South Pass City Weather Records (USC00488385)

Record envelope, standing records and threshold days for South Pass City (USC00488385), Wyoming, United States, with 115 years of record.

Key Facts for South Pass City

South Pass City (USC00488385) is a weather station in Wyoming, United States at 42.47 latitude and -108.80 longitude, 2,390 m (7,840 ft) above sea level.
The station reports from 1900 to 2014, 115 years of record.
1,464 records set at South Pass City still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
South Pass City set a daily record high minimum temperature of 5.6 C (42.1 F) on 16 October 2014.

About the Station

Location: Wyoming, United States, 42.47 latitude, -108.80 longitude.
Elevation: 2,390 m (7,840 ft).
Period of record: 1900 to 2014, 115 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at South Pass City. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at South Pass City, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	15.6 C (60.1 F)	-42.8 C (-45.0 F)	n/a	n/a
Feb	11.7 C (53.1 F)	-40.0 C (-40.0 F)	n/a	n/a
Mar	20.0 C (68.0 F)	-36.1 C (-33.0 F)	n/a	n/a
Apr	23.9 C (75.0 F)	-30.0 C (-22.0 F)	n/a	n/a
May	28.3 C (82.9 F)	-17.8 C (0.0 F)	n/a	n/a
Jun	33.9 C (93.0 F)	-14.4 C (6.1 F)	n/a	n/a
Jul	36.7 C (98.1 F)	-7.8 C (18.0 F)	n/a	n/a
Aug	38.9 C (102.0 F)	-12.8 C (9.0 F)	n/a	n/a
Sep	30.6 C (87.1 F)	-20.6 C (-5.1 F)	n/a	n/a
Oct	26.7 C (80.1 F)	-32.2 C (-26.0 F)	n/a	n/a
Nov	18.3 C (64.9 F)	-34.4 C (-29.9 F)	n/a	n/a
Dec	16.7 C (62.1 F)	-43.3 C (-45.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at South Pass City still stand. 1905 holds the most, with 39.

Standing records at South Pass City by the year they were set
Year set	Standing records
1900	25
1901	26
1902	13
1903	37
1904	26
1905	39
1906	25
1907	22
1909	11
1910	15
1911	16
1912	11
1913	35
1914	14
1915	17
1916	24
1917	28
1918	22
1919	22
1920	12
1921	15
1922	15
1923	10
1924	23
1925	11
1926	11
1927	16
1928	12
1929	13
1930	11
1931	21
1932	28
1933	19
1934	16
1935	16
1936	17
1937	19
1938	18
1939	14
1940	17
1941	10
1942	15
1943	22
1944	3
1945	25
1946	18
1947	14
1948	10
1949	10
1950	21
1951	10
1952	8
1953	6
1962	9
1963	23
1964	9
1965	12
1966	16
1967	11
1968	11
1969	22
1970	15
1971	14
1972	16
1974	2
1975	10
1976	14
1977	24
1978	25
1979	13
1980	4
1992	9
1993	10
1994	8
1995	13
1996	28
1997	6
1998	13
1999	16
2000	12
2001	9
2002	22
2003	32
2004	7
2005	5
2006	25
2007	28
2008	1
2009	8
2010	6
2011	5
2012	16
2014	1

All-Time Record Progression

6 new records

6 all-time records were set at South Pass City between 8 February 1933 and 3 January 1998. Each dot is a new record.

When South Pass City set new all-time records
Date	Kind	Detail
1933-02-08	Record low maximum temperature	Record low maximum temperature -23.9 C (-11.0 F)
1937-01-08	Record low maximum temperature	Record low maximum temperature -25.0 C (-13.0 F)
1949-08-08	Record high minimum temperature	Record high minimum temperature 19.4 C (66.9 F)
1952-05-16	Record daily precipitation	Record daily precipitation 50.8 mm (2.0 in)
1963-01-11	Record low maximum temperature	Record low maximum temperature -28.3 C (-18.9 F)
1998-01-03	Record daily precipitation	Record daily precipitation 57.9 mm (2.3 in)

Wettest Day of Each Month

Jan: 57.9 mm (2.3 in)

The wettest day on record for each calendar month at South Pass City. The most was 57.9 mm (2.3 in) on 3 January 1998.

Record daily precipitation for each month at South Pass City
Month	Record daily precipitation (mm)	Date
Jan	57.9 mm (2.3 in)	3 January 1998
Feb	45.7 mm (1.8 in)	25 February 1904
Mar	30.5 mm (1.2 in)	17 March 1907
Apr	34.8 mm (1.4 in)	21 April 1944
May	50.8 mm (2.0 in)	16 May 1952
Jun	37.8 mm (1.5 in)	11 June 1947
Jul	46.2 mm (1.8 in)	9 July 1926
Aug	32.8 mm (1.3 in)	26 August 1933
Sep	40.6 mm (1.6 in)	18 September 1978
Oct	38.1 mm (1.5 in)	20 October 1979
Nov	45.7 mm (1.8 in)	11 November 1903
Dec	36.6 mm (1.4 in)	22 December 1964

Period of Record Coverage

1900 to 2014

93 years of record at South Pass City, 1900 to 2014. 21 years have data for under 90 percent of days and are left out of rankings: 1900, 1902, 1903, 1905, 1907, 1909, 1952, 1953 and others.

Days with data per year at South Pass City
Year	Days with data	Share of year	Complete
1900	245	67%	No
1901	329	90%	Yes
1902	284	78%	No
1903	315	86%	No
1904	340	93%	Yes
1905	328	90%	No
1906	356	98%	Yes
1907	269	74%	No
1909	184	50%	No
1910	365	100%	Yes
1911	362	99%	Yes
1912	364	99%	Yes
1913	365	100%	Yes
1914	334	92%	Yes
1915	365	100%	Yes
1916	366	100%	Yes
1917	365	100%	Yes
1918	364	100%	Yes
1919	365	100%	Yes
1920	366	100%	Yes
1921	365	100%	Yes
1922	365	100%	Yes
1923	365	100%	Yes
1924	366	100%	Yes
1925	365	100%	Yes
1926	365	100%	Yes
1927	365	100%	Yes
1928	366	100%	Yes
1929	365	100%	Yes
1930	365	100%	Yes
1931	365	100%	Yes
1932	366	100%	Yes
1933	365	100%	Yes
1934	365	100%	Yes
1935	365	100%	Yes
1936	366	100%	Yes
1937	364	100%	Yes
1938	365	100%	Yes
1939	363	99%	Yes
1940	365	100%	Yes
1941	365	100%	Yes
1942	365	100%	Yes
1943	365	100%	Yes
1944	366	100%	Yes
1945	365	100%	Yes
1946	365	100%	Yes
1947	363	99%	Yes
1948	366	100%	Yes
1949	362	99%	Yes
1950	354	97%	Yes
1951	365	100%	Yes
1952	328	90%	No
1953	182	50%	No
1962	183	50%	No
1963	363	99%	Yes
1964	364	99%	Yes
1965	364	100%	Yes
1966	360	99%	Yes
1967	362	99%	Yes
1968	362	99%	Yes
1969	361	99%	Yes
1970	359	98%	Yes
1971	333	91%	Yes
1972	270	74%	No
1974	132	36%	No
1975	362	99%	Yes
1976	365	100%	Yes
1977	360	99%	Yes
1978	361	99%	Yes
1979	359	98%	Yes
1980	119	33%	No
1992	204	56%	No
1993	342	94%	Yes
1994	347	95%	Yes
1995	345	95%	Yes
1996	351	96%	Yes
1997	342	94%	Yes
1998	325	89%	No
1999	332	91%	Yes
2000	335	92%	Yes
2001	329	90%	Yes
2002	337	92%	Yes
2003	347	95%	Yes
2004	194	53%	No
2005	61	17%	No
2006	334	92%	Yes
2007	363	99%	Yes
2008	59	16%	No
2009	218	60%	No
2010	362	99%	Yes
2011	313	86%	No
2012	254	69%	No
2014	12	3%	No

Latest Records

Latest records at South Pass City
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
16 October 2014	South Pass City, US	daily high min	5.6 C (42.1 F)	1.7 C (3.1 F)	96 years	41 of 100 (Notable)
10 September 2012	South Pass City, US	daily high min	6.7 C (44.1 F)	0.6 C (1.1 F)	49 years	25 of 100 (Routine)
14 July 2012	South Pass City, US	daily high min (Tie)	11.1 C (52.0 F)	tie	74 years	8 of 100 (Routine)
5 July 2012	South Pass City, US	daily high min	10.6 C (51.1 F)	1.2 C (2.2 F)	75 years	35 of 100 (Notable)
1 July 2012	South Pass City, US	daily high max (Tie)	30.6 C (87.1 F)	tie	11 years	3 of 100 (Routine)
28 June 2012	South Pass City, US	daily high max (Tie)	30.0 C (86.0 F)	tie	46 years	5 of 100 (Routine)
26 May 2012	South Pass City, US	daily low max	0.6 C (33.1 F)	1.6 C (2.9 F)	95 years	40 of 100 (Notable)
24 April 2012	South Pass City, US	daily high max (Tie)	19.4 C (66.9 F)	tie	66 years	7 of 100 (Routine)
23 April 2012	South Pass City, US	daily high min	2.8 C (37.0 F)	1.1 C (2.0 F)	63 years	30 of 100 (Routine)
23 April 2012	South Pass City, US	daily high max	22.8 C (73.0 F)	1.7 C (3.1 F)	43 years	24 of 100 (Routine)
22 April 2012	South Pass City, US	daily high max	23.3 C (73.9 F)	2.2 C (4.0 F)	43 years	25 of 100 (Routine)
11 April 2012	South Pass City, US	daily high max	19.4 C (66.9 F)	2.2 C (4.0 F)	9 years	15 of 100 (Routine)
10 April 2012	South Pass City, US	daily high max	18.9 C (66.0 F)	0.6 C (1.1 F)	16 years	15 of 100 (Routine)
31 March 2012	South Pass City, US	daily high max	17.2 C (63.0 F)	2.8 C (5.0 F)	8 years	17 of 100 (Routine)
28 March 2012	South Pass City, US	daily high min (Tie)	-1.1 C (30.0 F)	tie	87 years	9 of 100 (Routine)
26 March 2012	South Pass City, US	daily high max	14.4 C (57.9 F)	1.1 C (2.0 F)	5 years	13 of 100 (Routine)
25 March 2012	South Pass City, US	daily high max	14.4 C (57.9 F)	2.2 C (4.0 F)	8 years	16 of 100 (Routine)
24 March 2012	South Pass City, US	daily high max	15.0 C (59.0 F)	1.1 C (2.0 F)	8 years	14 of 100 (Routine)
23 March 2012	South Pass City, US	daily high max	15.0 C (59.0 F)	0.6 C (1.1 F)	73 years	32 of 100 (Routine)
17 March 2012	South Pass City, US	daily high min	-1.1 C (30.0 F)	0.6 C (1.1 F)	45 years	23 of 100 (Routine)

Climate Trend

68 complete years, 1904 to 2010

One stripe for each of 68 complete years at South Pass City, 1904 to 2010. Blue stripes are years cooler than the station's own mean of 1.4 C (34.6 F); red stripes are warmer. The coolest year was 1945, at 0.1 C (32.2 F), and the warmest was 2007, at 3.7 C (38.7 F). The strongest colour marks a difference of 2.3 C (4.1 F).

Annual mean temperature at South Pass City as warming stripes, 1904 to 2010
Year	Annual mean temperature	Difference from the station mean
1904	2.6 C	+1.17 C
1906	1.1 C	-0.36 C
1910	2.5 C	+1.05 C
1911	0.7 C	-0.79 C
1912	0.2 C	-1.24 C
1913	0.9 C	-0.51 C
1915	1.5 C	+0.01 C
1916	0.5 C	-0.92 C
1917	0.2 C	-1.21 C
1918	1.5 C	+0.01 C
1919	1.6 C	+0.13 C
1920	0.6 C	-0.84 C
1921	2.2 C	+0.75 C
1922	0.3 C	-1.19 C
1923	0.5 C	-0.98 C
1924	0.4 C	-1.02 C
1925	1.8 C	+0.32 C
1926	1.7 C	+0.28 C
1927	0.8 C	-0.65 C
1928	0.6 C	-0.82 C
1929	0.5 C	-0.90 C
1930	0.6 C	-0.81 C
1931	1.7 C	+0.26 C
1932	0.2 C	-1.21 C
1933	1.1 C	-0.34 C
1934	2.9 C	+1.42 C
1935	0.6 C	-0.88 C
1936	0.7 C	-0.78 C
1937	0.2 C	-1.21 C
1938	0.7 C	-0.74 C
1939	1.9 C	+0.43 C
1940	2.6 C	+1.14 C
1941	1.9 C	+0.48 C
1942	1.1 C	-0.32 C
1943	1.8 C	+0.39 C
1944	0.9 C	-0.52 C
1945	0.1 C	-1.35 C
1946	0.9 C	-0.58 C
1947	0.7 C	-0.70 C
1948	0.8 C	-0.66 C
1949	1.9 C	+0.45 C
1950	1.7 C	+0.25 C
1951	0.6 C	-0.85 C
1963	3.6 C	+2.11 C
1964	1.5 C	+0.10 C
1965	2.1 C	+0.69 C
1966	2.7 C	+1.25 C
1967	2.7 C	+1.28 C
1968	2.1 C	+0.70 C
1969	3.1 C	+1.67 C
1970	2.4 C	+0.96 C
1975	1.0 C	-0.48 C
1976	1.6 C	+0.17 C
1977	2.6 C	+1.15 C
1978	0.7 C	-0.76 C
1979	0.8 C	-0.62 C
1993	0.6 C	-0.89 C
1994	1.9 C	+0.45 C
1995	1.6 C	+0.18 C
1996	1.7 C	+0.26 C
1997	1.3 C	-0.19 C
1999	2.0 C	+0.56 C
2000	1.8 C	+0.34 C
2001	2.4 C	+0.94 C
2002	1.2 C	-0.23 C
2003	2.4 C	+1.00 C
2007	3.7 C	+2.28 C
2010	2.0 C	+0.59 C

The annual mean temperature here has risen by 0.11 C (0.05 to 0.18) per decade over 1904 to 2010. In Fahrenheit: 0.2 F (0.1 to 0.3) per decade. The slope is a straight line fitted to 68 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at South Pass City
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.11 C (0.05 to 0.18) per decade	0.2 F (0.1 to 0.3) per decade	1904 to 2010	68	Rise
Mean daily maximum	0.1 C (0.1 to 0.2) per decade	0.3 F (0.1 to 0.4) per decade	1904 to 2010	68	Rise
Mean daily minimum	0.08 C (-0.01 to 0.17) per decade	0.15 F (-0.02 to 0.31) per decade	1904 to 2010	68	Not clearly different from zero

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1900 to 2014

Yearly extremes at South Pass City: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.9 C (102.0 F)	1903	29.4 C (84.9 F)	93
Coldest night (TNn)	-43.3 C (-45.9 F)	1924	-32.8 C (-27.0 F)	93
Wettest day (Rx1day)	57.9 mm (2.3 in)	1998	24.9 mm (1.0 in)	103
Wettest five days (Rx5day)	87.1 mm (3.4 in)	1972	37.8 mm (1.5 in)	103
Longest dry spell (CDD)	79 days	1928	30 days	103

Hottest day (TXx)

The hottest day of the year at South Pass City, 1900 to 2014. The record is 38.9 C (102.0 F) in 1903, marked on the chart; the median year is 29.4 C (84.9 F).

Hottest day (TXx) at South Pass City by year
Year	Hottest day (TXx)
1900	32.8 C (91.0 F)
1901	36.7 C (98.1 F)
1902	30.0 C (86.0 F)
1903	38.9 C (102.0 F)
1904	31.1 C (88.0 F)
1905	31.7 C (89.1 F)
1906	35.0 C (95.0 F)
1907	29.4 C (84.9 F)
1909	28.9 C (84.0 F)
1910	28.3 C (82.9 F)
1911	33.9 C (93.0 F)
1912	26.7 C (80.1 F)
1913	27.8 C (82.0 F)
1914	27.2 C (81.0 F)
1915	26.7 C (80.1 F)
1916	28.3 C (82.9 F)
1917	28.9 C (84.0 F)
1918	30.6 C (87.1 F)
1919	30.6 C (87.1 F)
1920	29.4 C (84.9 F)
1921	30.0 C (86.0 F)
1922	28.9 C (84.0 F)
1923	30.0 C (86.0 F)
1924	29.4 C (84.9 F)
1925	32.2 C (90.0 F)
1926	30.6 C (87.1 F)
1927	29.4 C (84.9 F)
1928	28.9 C (84.0 F)
1929	30.6 C (87.1 F)
1930	29.4 C (84.9 F)
1931	32.8 C (91.0 F)
1932	28.3 C (82.9 F)
1933	30.0 C (86.0 F)
1934	30.6 C (87.1 F)
1935	30.6 C (87.1 F)
1936	29.4 C (84.9 F)
1937	28.9 C (84.0 F)
1938	28.9 C (84.0 F)
1939	36.1 C (97.0 F)
1940	32.2 C (90.0 F)
1941	30.0 C (86.0 F)
1942	30.0 C (86.0 F)
1943	30.0 C (86.0 F)
1944	26.7 C (80.1 F)
1945	28.3 C (82.9 F)
1946	27.8 C (82.0 F)
1947	27.2 C (81.0 F)
1948	28.3 C (82.9 F)
1949	29.4 C (84.9 F)
1950	28.9 C (84.0 F)
1951	30.0 C (86.0 F)
1952	28.3 C (82.9 F)
1953	29.4 C (84.9 F)
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	29.4 C (84.9 F)
1963	28.3 C (82.9 F)
1964	28.9 C (84.0 F)
1965	28.9 C (84.0 F)
1966	30.0 C (86.0 F)
1967	28.3 C (82.9 F)
1968	30.6 C (87.1 F)
1969	30.0 C (86.0 F)
1970	31.7 C (89.1 F)
1971	30.0 C (86.0 F)
1972	28.9 C (84.0 F)
1973	n/a
1974	28.3 C (82.9 F)
1975	28.9 C (84.0 F)
1976	31.1 C (88.0 F)
1977	30.6 C (87.1 F)
1978	29.4 C (84.9 F)
1979	30.6 C (87.1 F)
1980	23.3 C (73.9 F)
1991	n/a
1992	28.9 C (84.0 F)
1993	27.2 C (81.0 F)
1994	30.6 C (87.1 F)
1995	29.4 C (84.9 F)
1996	30.6 C (87.1 F)
1997	29.4 C (84.9 F)
1998	31.7 C (89.1 F)
1999	28.9 C (84.0 F)
2000	31.1 C (88.0 F)
2001	31.7 C (89.1 F)
2002	32.2 C (90.0 F)
2003	31.7 C (89.1 F)
2004	28.3 C (82.9 F)
2005	12.8 C (55.0 F)
2006	32.8 C (91.0 F)
2007	32.2 C (90.0 F)
2008	6.1 C (43.0 F)
2009	30.0 C (86.0 F)
2010	30.0 C (86.0 F)
2011	29.4 C (84.9 F)
2012	30.6 C (87.1 F)
2014	18.9 C (66.0 F)

Coldest night (TNn)

The coldest night of the year at South Pass City, 1900 to 2014. The record is -43.3 C (-45.9 F) in 1924, marked on the chart; the median year is -32.8 C (-27.0 F).

Coldest night (TNn) at South Pass City by year
Year	Coldest night (TNn)
1900	-27.2 C (-17.0 F)
1901	-30.0 C (-22.0 F)
1902	-31.7 C (-25.1 F)
1903	-37.8 C (-36.0 F)
1904	-35.0 C (-31.0 F)
1905	-40.0 C (-40.0 F)
1906	-36.1 C (-33.0 F)
1907	-25.0 C (-13.0 F)
1909	-34.4 C (-29.9 F)
1910	-35.0 C (-31.0 F)
1911	-36.1 C (-33.0 F)
1912	-31.7 C (-25.1 F)
1913	-39.4 C (-38.9 F)
1914	-32.2 C (-26.0 F)
1915	-36.1 C (-33.0 F)
1916	-38.3 C (-36.9 F)
1917	-39.4 C (-38.9 F)
1918	-37.2 C (-35.0 F)
1919	-35.6 C (-32.1 F)
1920	-30.0 C (-22.0 F)
1921	-30.6 C (-23.1 F)
1922	-42.8 C (-45.0 F)
1923	-37.8 C (-36.0 F)
1924	-43.3 C (-45.9 F)
1925	-28.9 C (-20.0 F)
1926	-33.3 C (-27.9 F)
1927	-35.6 C (-32.1 F)
1928	-32.2 C (-26.0 F)
1929	-37.2 C (-35.0 F)
1930	-40.0 C (-40.0 F)
1931	-32.8 C (-27.0 F)
1932	-35.6 C (-32.1 F)
1933	-38.9 C (-38.0 F)
1934	-28.3 C (-18.9 F)
1935	-37.8 C (-36.0 F)
1936	-37.8 C (-36.0 F)
1937	-38.9 C (-38.0 F)
1938	-33.9 C (-29.0 F)
1939	-36.7 C (-34.1 F)
1940	-35.0 C (-31.0 F)
1941	-31.1 C (-24.0 F)
1942	-37.2 C (-35.0 F)
1943	-36.7 C (-34.1 F)
1944	-31.1 C (-24.0 F)
1945	-30.0 C (-22.0 F)
1946	-31.1 C (-24.0 F)
1947	-31.1 C (-24.0 F)
1948	-37.8 C (-36.0 F)
1949	-33.3 C (-27.9 F)
1950	-31.7 C (-25.1 F)
1951	-36.1 C (-33.0 F)
1952	-33.3 C (-27.9 F)
1953	-12.8 C (9.0 F)
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	-28.3 C (-18.9 F)
1963	-36.1 C (-33.0 F)
1964	-35.0 C (-31.0 F)
1965	-30.6 C (-23.1 F)
1966	-29.4 C (-20.9 F)
1967	-25.6 C (-14.1 F)
1968	-28.9 C (-20.0 F)
1969	-27.8 C (-18.0 F)
1970	-30.0 C (-22.0 F)
1971	-32.8 C (-27.0 F)
1972	-31.7 C (-25.1 F)
1973	n/a
1974	-30.0 C (-22.0 F)
1975	-31.7 C (-25.1 F)
1976	-31.7 C (-25.1 F)
1977	-33.9 C (-29.0 F)
1978	-34.4 C (-29.9 F)
1979	-40.0 C (-40.0 F)
1980	-36.7 C (-34.1 F)
1991	n/a
1992	-32.8 C (-27.0 F)
1993	-30.6 C (-23.1 F)
1994	-28.3 C (-18.9 F)
1995	-28.9 C (-20.0 F)
1996	-36.7 C (-34.1 F)
1997	-28.3 C (-18.9 F)
1998	-32.8 C (-27.0 F)
1999	-30.0 C (-22.0 F)
2000	-28.9 C (-20.0 F)
2001	-31.1 C (-24.0 F)
2002	-34.4 C (-29.9 F)
2003	-35.0 C (-31.0 F)
2004	-33.3 C (-27.9 F)
2005	-31.1 C (-24.0 F)
2006	-31.7 C (-25.1 F)
2007	-31.7 C (-25.1 F)
2008	-23.9 C (-11.0 F)
2009	-33.9 C (-29.0 F)
2010	-32.2 C (-26.0 F)
2011	-36.1 C (-33.0 F)
2012	-26.7 C (-16.1 F)
2014	-7.2 C (19.0 F)

Wettest day (Rx1day)

The wettest day of the year at South Pass City, 1900 to 2014. The record is 57.9 mm (2.3 in) in 1998, marked on the chart; the median year is 24.9 mm (1.0 in).

Wettest day (Rx1day) at South Pass City by year
Year	Wettest day (Rx1day)
1900	15.2 mm (0.6 in)
1901	30.5 mm (1.2 in)
1902	23.9 mm (0.9 in)
1903	45.7 mm (1.8 in)
1904	45.7 mm (1.8 in)
1905	35.6 mm (1.4 in)
1906	29.2 mm (1.1 in)
1907	30.5 mm (1.2 in)
1909	37.8 mm (1.5 in)
1910	20.3 mm (0.8 in)
1911	30.5 mm (1.2 in)
1912	23.1 mm (0.9 in)
1913	9.4 mm (0.37 in)
1914	17.3 mm (0.7 in)
1915	26.7 mm (1.1 in)
1916	12.7 mm (0.5 in)
1917	13.5 mm (0.5 in)
1918	15.7 mm (0.6 in)
1919	20.6 mm (0.8 in)
1920	20.3 mm (0.8 in)
1921	24.9 mm (1.0 in)
1922	20.6 mm (0.8 in)
1923	33.5 mm (1.3 in)
1924	17.5 mm (0.7 in)
1925	19.1 mm (0.8 in)
1926	46.2 mm (1.8 in)
1927	25.7 mm (1.0 in)
1928	20.6 mm (0.8 in)
1929	24.4 mm (1.0 in)
1930	27.4 mm (1.1 in)
1931	22.9 mm (0.9 in)
1932	32.3 mm (1.3 in)
1933	32.8 mm (1.3 in)
1934	27.4 mm (1.1 in)
1935	19.1 mm (0.8 in)
1936	24.1 mm (0.9 in)
1937	27.4 mm (1.1 in)
1938	16.3 mm (0.6 in)
1939	18.5 mm (0.7 in)
1940	22.4 mm (0.9 in)
1941	27.7 mm (1.1 in)
1942	27.7 mm (1.1 in)
1943	25.9 mm (1.0 in)
1944	34.8 mm (1.4 in)
1945	34.8 mm (1.4 in)
1946	20.6 mm (0.8 in)
1947	37.8 mm (1.5 in)
1948	21.1 mm (0.8 in)
1949	18.0 mm (0.7 in)
1950	33.0 mm (1.3 in)
1951	24.1 mm (0.9 in)
1952	50.8 mm (2.0 in)
1953	14.7 mm (0.6 in)
1954	12.2 mm (0.5 in)
1955	17.8 mm (0.7 in)
1956	26.7 mm (1.1 in)
1957	25.4 mm (1.0 in)
1958	20.3 mm (0.8 in)
1959	17.0 mm (0.7 in)
1960	26.7 mm (1.1 in)
1961	15.0 mm (0.6 in)
1962	20.6 mm (0.8 in)
1963	34.5 mm (1.4 in)
1964	36.6 mm (1.4 in)
1965	22.4 mm (0.9 in)
1966	17.8 mm (0.7 in)
1967	23.4 mm (0.9 in)
1968	13.2 mm (0.5 in)
1969	29.0 mm (1.1 in)
1970	17.0 mm (0.7 in)
1971	25.7 mm (1.0 in)
1972	29.7 mm (1.2 in)
1973	8.1 mm (0.32 in)
1974	13.5 mm (0.5 in)
1975	22.1 mm (0.9 in)
1976	35.8 mm (1.4 in)
1977	24.9 mm (1.0 in)
1978	40.6 mm (1.6 in)
1979	38.1 mm (1.5 in)
1980	26.9 mm (1.1 in)
1991	28.7 mm (1.1 in)
1992	19.3 mm (0.8 in)
1993	30.5 mm (1.2 in)
1994	25.4 mm (1.0 in)
1995	27.9 mm (1.1 in)
1996	27.4 mm (1.1 in)
1997	36.3 mm (1.4 in)
1998	57.9 mm (2.3 in)
1999	27.2 mm (1.1 in)
2000	32.3 mm (1.3 in)
2001	17.8 mm (0.7 in)
2002	15.7 mm (0.6 in)
2003	17.8 mm (0.7 in)
2004	33.0 mm (1.3 in)
2005	13.2 mm (0.5 in)
2006	24.9 mm (1.0 in)
2007	23.6 mm (0.9 in)
2008	10.4 mm (0.4 in)
2009	38.1 mm (1.5 in)
2010	38.1 mm (1.5 in)
2011	41.9 mm (1.6 in)
2012	12.7 mm (0.5 in)
2014	0.0 mm (0.00 in)

Wettest five days (Rx5day)

The wettest five days of the year at South Pass City, 1900 to 2014. The record is 87.1 mm (3.4 in) in 1972, marked on the chart; the median year is 37.8 mm (1.5 in).

Wettest five days (Rx5day) at South Pass City by year
Year	Wettest five days (Rx5day)
1900	34.3 mm (1.4 in)
1901	43.2 mm (1.7 in)
1902	23.9 mm (0.9 in)
1903	68.5 mm (2.7 in)
1904	66.0 mm (2.6 in)
1905	35.6 mm (1.4 in)
1906	47.5 mm (1.9 in)
1907	68.6 mm (2.7 in)
1909	47.9 mm (1.9 in)
1910	49.1 mm (1.9 in)
1911	60.5 mm (2.4 in)
1912	26.6 mm (1.0 in)
1913	16.3 mm (0.6 in)
1914	25.4 mm (1.0 in)
1915	43.8 mm (1.7 in)
1916	20.0 mm (0.8 in)
1917	36.9 mm (1.5 in)
1918	31.6 mm (1.2 in)
1919	28.0 mm (1.1 in)
1920	33.8 mm (1.3 in)
1921	42.0 mm (1.7 in)
1922	28.9 mm (1.1 in)
1923	39.1 mm (1.5 in)
1924	26.9 mm (1.1 in)
1925	36.2 mm (1.4 in)
1926	86.5 mm (3.4 in)
1927	35.4 mm (1.4 in)
1928	37.8 mm (1.5 in)
1929	40.9 mm (1.6 in)
1930	43.9 mm (1.7 in)
1931	32.8 mm (1.3 in)
1932	44.3 mm (1.7 in)
1933	37.9 mm (1.5 in)
1934	27.7 mm (1.1 in)
1935	23.1 mm (0.9 in)
1936	48.8 mm (1.9 in)
1937	53.6 mm (2.1 in)
1938	28.3 mm (1.1 in)
1939	19.0 mm (0.7 in)
1940	26.7 mm (1.1 in)
1941	46.2 mm (1.8 in)
1942	55.9 mm (2.2 in)
1943	48.3 mm (1.9 in)
1944	45.3 mm (1.8 in)
1945	65.6 mm (2.6 in)
1946	27.2 mm (1.1 in)
1947	69.1 mm (2.7 in)
1948	41.9 mm (1.6 in)
1949	47.5 mm (1.9 in)
1950	44.2 mm (1.7 in)
1951	37.3 mm (1.5 in)
1952	53.1 mm (2.1 in)
1953	22.3 mm (0.9 in)
1954	21.9 mm (0.9 in)
1955	46.2 mm (1.8 in)
1956	37.1 mm (1.5 in)
1957	44.2 mm (1.7 in)
1958	20.3 mm (0.8 in)
1959	27.7 mm (1.1 in)
1960	34.1 mm (1.3 in)
1961	29.5 mm (1.2 in)
1962	36.4 mm (1.4 in)
1963	56.4 mm (2.2 in)
1964	71.1 mm (2.8 in)
1965	31.8 mm (1.3 in)
1966	30.7 mm (1.2 in)
1967	35.6 mm (1.4 in)
1968	32.0 mm (1.3 in)
1969	62.0 mm (2.4 in)
1970	31.0 mm (1.2 in)
1971	74.5 mm (2.9 in)
1972	87.1 mm (3.4 in)
1973	8.9 mm (0.35 in)
1974	13.5 mm (0.5 in)
1975	37.3 mm (1.5 in)
1976	42.1 mm (1.7 in)
1977	42.2 mm (1.7 in)
1978	42.1 mm (1.7 in)
1979	51.5 mm (2.0 in)
1980	69.4 mm (2.7 in)
1991	33.5 mm (1.3 in)
1992	21.8 mm (0.9 in)
1993	71.0 mm (2.8 in)
1994	45.7 mm (1.8 in)
1995	37.8 mm (1.5 in)
1996	52.8 mm (2.1 in)
1997	51.3 mm (2.0 in)
1998	57.9 mm (2.3 in)
1999	63.7 mm (2.5 in)
2000	33.3 mm (1.3 in)
2001	22.4 mm (0.9 in)
2002	25.9 mm (1.0 in)
2003	32.8 mm (1.3 in)
2004	38.3 mm (1.5 in)
2005	13.5 mm (0.5 in)
2006	24.9 mm (1.0 in)
2007	40.1 mm (1.6 in)
2008	12.2 mm (0.5 in)
2009	41.9 mm (1.6 in)
2010	49.5 mm (1.9 in)
2011	63.9 mm (2.5 in)
2012	28.4 mm (1.1 in)
2014	0.0 mm (0.00 in)

Longest dry spell (CDD)

The longest dry spell of the year at South Pass City, 1900 to 2014. The record is 79 days in 1928, marked on the chart; the median year is 30 days.

Longest dry spell (CDD) at South Pass City by year
Year	Longest dry spell (CDD)
1900	33 days
1901	23 days
1902	31 days
1903	35 days
1904	43 days
1905	43 days
1906	21 days
1907	36 days
1909	35 days
1910	34 days
1911	27 days
1912	29 days
1913	34 days
1914	69 days
1915	33 days
1916	25 days
1917	37 days
1918	25 days
1919	39 days
1920	49 days
1921	44 days
1922	60 days
1923	18 days
1924	37 days
1925	19 days
1926	23 days
1927	26 days
1928	79 days
1929	61 days
1930	38 days
1931	41 days
1932	37 days
1933	45 days
1934	36 days
1935	32 days
1936	27 days
1937	26 days
1938	23 days
1939	58 days
1940	46 days
1941	24 days
1942	25 days
1943	23 days
1944	31 days
1945	24 days
1946	27 days
1947	40 days
1948	26 days
1949	16 days
1950	48 days
1951	26 days
1952	77 days
1953	32 days
1954	30 days
1955	28 days
1956	35 days
1957	17 days
1958	52 days
1959	29 days
1960	41 days
1961	33 days
1962	39 days
1963	29 days
1964	34 days
1965	25 days
1966	20 days
1967	18 days
1968	15 days
1969	32 days
1970	21 days
1971	19 days
1972	22 days
1973	20 days
1974	21 days
1975	29 days
1976	35 days
1977	49 days
1978	40 days
1979	57 days
1980	23 days
1991	23 days
1992	45 days
1993	19 days
1994	19 days
1995	19 days
1996	28 days
1997	20 days
1998	27 days
1999	24 days
2000	31 days
2001	22 days
2002	31 days
2003	35 days
2004	32 days
2005	14 days
2006	29 days
2007	39 days
2008	8 days
2009	30 days
2010	37 days
2011	41 days
2012	25 days
2014	5 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

68 years with a frost

Across 68 years with a frost, the median last spring frost at South Pass City falls on 28 June and the median first autumn frost on 3 July, which leaves a median of 6 days between them.

In 1947 to 2010 the median growing season was 16 days. That is 10 days more than in 1904 to 1938.

Fitted over all years, the growing season changes by +2.2 days per decade at this station.

Frost dates and growing season at South Pass City
Measure	Median, all years	Earliest period (1904 to 1938)	Recent period (1947 to 2010)	Recent against earliest	Fitted trend
Last spring frost	28 June	28 June	27 June	1 day earlier	-0.1 days per decade
First autumn frost	3 July	2 July	7 July	5 days later	+2.1 days per decade
Growing days	6 days	6 days	16 days	10 days more	+2.2 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

80 years, 1903 to 2011

A day with at least 24.4 mm (1.0 in) of rain is expected about once in 2 years. A day with at least 51.1 mm (2.0 in) of rain is expected about once in 100 years.

Rainfall return levels at South Pass City: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	24.4 mm (1.0 in)
5 years	32.0 mm (1.3 in)
10 years	36.9 mm (1.5 in)
25 years	42.8 mm (1.7 in)
50 years	47.0 mm (1.9 in)
100 years	51.1 mm (2.0 in)	Longer than the 80 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 80 years of values from 1903 to 2011.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 50.8 mm (2.0 in) in 1952; 46.2 mm (1.8 in) in 1926; 45.7 mm (1.8 in) in 1903.

Station Changes

3 suspected

3 changes were suspected in the annual mean temperature of South Pass City, at 1930, 1949 and 1978. Each is measured against neighbouring stations.

Relative to 5 neighbouring stations, the station's annual mean temperature from 1930 ran 0.5 C (0.8 F) lower than in the years before (possible change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1949 ran 0.9 C (1.7 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1978 ran 1.2 C (2.1 F) lower than in the years before (likely change).

Suspected changes in the annual mean temperature at South Pass City, against neighbouring stations
Year	Shift (C)	Shift (F)	Strength	Neighbours
1930	-0.5	-0.8	possible	5
1949	+0.9	+1.7	likely	5
1978	-1.2	-2.1	likely	5

Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.

Download the Data

Data for South Pass City standing records by year: CSV or JSON. Field meanings are on the data page.
Data for South Pass City threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).