Afton Weather Records (USC00130064)

Record envelope, standing records and threshold days for Afton (USC00130064), Iowa, United States, with 57 years of record.

Key Facts for Afton

Afton (USC00130064) is a weather station in Iowa, United States at 41.03 latitude and -94.20 longitude, 366 m (1,201 ft) above sea level.
The station reports from 1894 to 1950, 57 years of record.
1,464 records set at Afton still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Afton set a daily record precipitation of 11.4 mm (0.4 in) on 13 January 1950.

About the Station

Location: Iowa, United States, 41.03 latitude, -94.20 longitude.
Elevation: 366 m (1,201 ft).
Period of record: 1894 to 1950, 57 years.
Eligible elements: tmax, tmin, prcp, snow.

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 Afton. 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 Afton, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	17.2 C (63.0 F)	-34.4 C (-29.9 F)	n/a	n/a
Feb	26.1 C (79.0 F)	-31.7 C (-25.1 F)	n/a	n/a
Mar	31.1 C (88.0 F)	-25.0 C (-13.0 F)	n/a	n/a
Apr	34.4 C (93.9 F)	-11.7 C (10.9 F)	n/a	n/a
May	38.3 C (100.9 F)	-5.0 C (23.0 F)	n/a	n/a
Jun	39.4 C (102.9 F)	1.1 C (34.0 F)	n/a	n/a
Jul	44.4 C (111.9 F)	7.2 C (45.0 F)	n/a	n/a
Aug	43.9 C (111.0 F)	3.3 C (37.9 F)	n/a	n/a
Sep	40.6 C (105.1 F)	-4.4 C (24.1 F)	n/a	n/a
Oct	33.3 C (91.9 F)	-15.6 C (3.9 F)	n/a	n/a
Nov	27.8 C (82.0 F)	-20.6 C (-5.1 F)	n/a	n/a
Dec	20.6 C (69.1 F)	-32.8 C (-27.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Afton still stand. 1934 holds the most, with 60.

Standing records at Afton by the year they were set
Year set	Standing records
1894	15
1895	29
1896	31
1897	33
1898	28
1899	33
1900	15
1901	27
1902	27
1903	27
1904	19
1905	21
1906	18
1907	24
1908	14
1909	27
1910	25
1911	31
1912	26
1913	42
1914	23
1915	26
1916	21
1917	33
1918	25
1919	14
1920	20
1921	25
1922	11
1923	21
1924	29
1925	39
1926	15
1927	22
1928	30
1929	17
1930	39
1931	40
1932	29
1933	33
1934	60
1935	26
1936	60
1937	28
1938	24
1939	40
1940	17
1941	16
1942	25
1943	23
1944	27
1945	16
1946	25
1947	17
1948	16
1949	20

All-Time Record Progression

3 new records

3 all-time records were set at Afton between 28 June 1931 and 25 July 1936. Each dot is a new record.

When Afton set new all-time records
Date	Kind	Detail
1931-06-28	Record high minimum temperature	Record high minimum temperature 28.9 C (84.0 F)
1934-08-08	Record high maximum temperature	Record high maximum temperature 43.9 C (111.0 F)
1936-07-25	Record high maximum temperature	Record high maximum temperature 44.4 C (111.9 F)

Wettest Day of Each Month

Aug: 236.2 mm (9.3 in)

The wettest day on record for each calendar month at Afton. The most was 236.2 mm (9.3 in) on 27 August 1903.

Record daily precipitation for each month at Afton
Month	Record daily precipitation (mm)	Date
Jan	36.1 mm (1.4 in)	20 January 1904
Feb	50.8 mm (2.0 in)	17 February 1911
Mar	100.6 mm (4.0 in)	31 March 1897
Apr	88.1 mm (3.5 in)	24 April 1897
May	94.2 mm (3.7 in)	26 May 1915
Jun	109.7 mm (4.3 in)	24 June 1949
Jul	96.0 mm (3.8 in)	28 July 1915
Aug	236.2 mm (9.3 in)	27 August 1903
Sep	134.9 mm (5.3 in)	14 September 1914
Oct	79.0 mm (3.1 in)	31 October 1900
Nov	85.1 mm (3.4 in)	23 November 1931
Dec	40.6 mm (1.6 in)	3 December 1897

Period of Record Coverage

1894 to 1950

57 years of record at Afton, 1894 to 1950. 5 years have data for under 90 percent of days and are left out of rankings: 1894, 1904, 1929, 1930, 1950.

Days with data per year at Afton
Year	Days with data	Share of year	Complete
1894	209	57%	No
1895	353	97%	Yes
1896	360	98%	Yes
1897	363	99%	Yes
1898	364	100%	Yes
1899	330	90%	Yes
1900	363	99%	Yes
1901	359	98%	Yes
1902	358	98%	Yes
1903	355	97%	Yes
1904	311	85%	No
1905	340	93%	Yes
1906	358	98%	Yes
1907	359	98%	Yes
1908	362	99%	Yes
1909	364	100%	Yes
1910	350	96%	Yes
1911	341	93%	Yes
1912	364	99%	Yes
1913	332	91%	Yes
1914	359	98%	Yes
1915	331	91%	Yes
1916	353	96%	Yes
1917	364	100%	Yes
1918	364	100%	Yes
1919	330	90%	Yes
1920	358	98%	Yes
1921	359	98%	Yes
1922	363	99%	Yes
1923	360	99%	Yes
1924	361	99%	Yes
1925	360	99%	Yes
1926	353	97%	Yes
1927	335	92%	Yes
1928	362	99%	Yes
1929	325	89%	No
1930	310	85%	No
1931	362	99%	Yes
1932	365	100%	Yes
1933	363	99%	Yes
1934	363	99%	Yes
1935	331	91%	Yes
1936	361	99%	Yes
1937	362	99%	Yes
1938	365	100%	Yes
1939	365	100%	Yes
1940	366	100%	Yes
1941	365	100%	Yes
1942	363	99%	Yes
1943	363	99%	Yes
1944	366	100%	Yes
1945	363	99%	Yes
1946	351	96%	Yes
1947	359	98%	Yes
1948	354	97%	Yes
1949	343	94%	Yes
1950	41	11%	No

Latest Records

Latest records at Afton
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
13 January 1950	Afton, US	daily rain	11.4 mm (0.4 in)	3.0 mm (0.12 in)	10 years	12 of 100 (Routine)
2 January 1950	Afton, US	daily high min (Tie)	1.1 C (34.0 F)	tie	11 years	2 of 100 (Routine)
23 December 1949	Afton, US	daily low min	-22.2 C (-8.0 F)	0.5 C (0.9 F)	6 years	6 of 100 (Routine)
11 December 1949	Afton, US	daily high max	15.0 C (59.0 F)	0.6 C (1.1 F)	52 years	20 of 100 (Routine)
28 November 1949	Afton, US	daily high max	17.8 C (64.0 F)	1.1 C (2.0 F)	8 years	8 of 100 (Routine)
11 November 1949	Afton, US	daily high max	25.0 C (77.0 F)	3.3 C (5.9 F)	26 years	16 of 100 (Routine)
5 November 1949	Afton, US	daily low min	-7.8 C (18.0 F)	1.7 C (3.1 F)	52 years	22 of 100 (Routine)
31 October 1949	Afton, US	daily low min	-11.1 C (12.0 F)	3.3 C (5.9 F)	36 years	21 of 100 (Routine)
8 October 1949	Afton, US	daily high min	17.8 C (64.0 F)	2.8 C (5.0 F)	44 years	23 of 100 (Routine)
23 September 1949	Afton, US	daily low min	1.1 C (34.0 F)	0.6 C (1.1 F)	32 years	15 of 100 (Routine)
13 September 1949	Afton, US	daily low min	1.1 C (34.0 F)	0.6 C (1.1 F)	47 years	20 of 100 (Routine)
13 September 1949	Afton, US	daily low max (Tie)	15.6 C (60.1 F)	tie	6 years	1 of 100 (Routine)
8 September 1949	Afton, US	daily low min	5.6 C (42.1 F)	2.2 C (4.0 F)	15 years	13 of 100 (Routine)
7 September 1949	Afton, US	daily low max	18.3 C (64.9 F)	1.1 C (2.0 F)	40 years	18 of 100 (Routine)
1 September 1949	Afton, US	daily low min	2.2 C (36.0 F)	6.7 C (12.1 F)	53 years	33 of 100 (Routine)
30 July 1949	Afton, US	daily low min	10.6 C (51.1 F)	0.5 C (0.9 F)	49 years	20 of 100 (Routine)
20 July 1949	Afton, US	daily rain	79.2 mm (3.1 in)	40.6 mm (1.6 in)	20 years	38 of 100 (Notable)
14 July 1949	Afton, US	daily low max	23.3 C (73.9 F)	1.1 C (2.0 F)	19 years	12 of 100 (Routine)
24 June 1949	Afton, US	monthly rain	109.7 mm (4.3 in)	4.5 mm (0.18 in)	19 years	22 of 100 (Routine)
13 June 1949	Afton, US	daily rain	26.2 mm (1.0 in)	0.3 mm (0.01 in)	48 years	19 of 100 (Routine)

Climate Trend

38 complete years, 1895 to 1948

One stripe for each of 38 complete years at Afton, 1895 to 1948. Blue stripes are years cooler than the station's own mean of 10.4 C (50.6 F); red stripes are warmer. The coolest year was 1917, at 8.8 C (47.8 F), and the warmest was 1931, at 12.8 C (55.1 F). The strongest colour marks a difference of 2.5 C (4.5 F).

Annual mean temperature at Afton as warming stripes, 1895 to 1948
Year	Annual mean temperature	Difference from the station mean
1895	9.1 C	-1.21 C
1896	10.2 C	-0.15 C
1897	10.0 C	-0.35 C
1898	9.8 C	-0.60 C
1900	10.4 C	0.00 C
1901	9.9 C	-0.43 C
1902	9.5 C	-0.84 C
1903	9.5 C	-0.85 C
1906	10.2 C	-0.18 C
1907	9.8 C	-0.59 C
1908	10.6 C	+0.29 C
1909	9.8 C	-0.58 C
1912	8.8 C	-1.53 C
1914	10.7 C	+0.38 C
1917	8.8 C	-1.59 C
1921	12.4 C	+2.01 C
1922	11.0 C	+0.69 C
1923	10.6 C	+0.21 C
1924	9.3 C	-1.09 C
1925	10.8 C	+0.43 C
1926	10.3 C	-0.05 C
1928	10.7 C	+0.32 C
1931	12.8 C	+2.46 C
1932	10.0 C	-0.32 C
1933	11.5 C	+1.17 C
1934	12.2 C	+1.84 C
1936	10.3 C	-0.05 C
1937	9.8 C	-0.59 C
1938	11.8 C	+1.49 C
1939	11.9 C	+1.55 C
1940	9.8 C	-0.59 C
1941	11.5 C	+1.10 C
1942	10.3 C	-0.10 C
1943	9.5 C	-0.85 C
1944	9.9 C	-0.47 C
1945	9.2 C	-1.13 C
1946	11.4 C	+1.03 C
1948	9.7 C	-0.67 C

The fitted trend in annual mean temperature here over 1895 to 1948 is 0.18 C (-0.01 to 0.37) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.33 F (-0.01 to 0.67) per decade. The slope is a straight line fitted to 38 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Afton
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.18 C (-0.01 to 0.37) per decade	0.33 F (-0.01 to 0.67) per decade	1895 to 1948	38	Not clearly different from zero
Mean daily maximum	0.1 C (-0.1 to 0.3) per decade	0.2 F (-0.1 to 0.6) per decade	1895 to 1948	38	Not clearly different from zero
Mean daily minimum	0.24 C (0.04 to 0.43) per decade	0.4 F (0.1 to 0.8) per decade	1895 to 1948	38	Rise

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

1894 to 1950

Yearly extremes at Afton: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	44.4 C (111.9 F)	1936	37.8 C (100.0 F)	57
Coldest night (TNn)	-34.4 C (-29.9 F)	1912	-25.6 C (-14.1 F)	57
Wettest day (Rx1day)	236.2 mm (9.3 in)	1903	67.8 mm (2.7 in)	57
Wettest five days (Rx5day)	263.4 mm (10.4 in)	1903	106.2 mm (4.2 in)	57
Longest dry spell (CDD)	52 days	1904	27 days	57

Hottest day (TXx)

The hottest day of the year at Afton, 1894 to 1950. The record is 44.4 C (111.9 F) in 1936, marked on the chart; the median year is 37.8 C (100.0 F).

Hottest day (TXx) at Afton by year
Year	Hottest day (TXx)
1894	41.7 C (107.1 F)
1895	36.7 C (98.1 F)
1896	36.7 C (98.1 F)
1897	40.6 C (105.1 F)
1898	38.3 C (100.9 F)
1899	36.7 C (98.1 F)
1900	36.7 C (98.1 F)
1901	41.7 C (107.1 F)
1902	35.0 C (95.0 F)
1903	36.1 C (97.0 F)
1904	34.4 C (93.9 F)
1905	36.7 C (98.1 F)
1906	36.7 C (98.1 F)
1907	35.6 C (96.1 F)
1908	35.6 C (96.1 F)
1909	37.2 C (99.0 F)
1910	37.2 C (99.0 F)
1911	40.6 C (105.1 F)
1912	35.6 C (96.1 F)
1913	40.6 C (105.1 F)
1914	41.1 C (106.0 F)
1915	33.9 C (93.0 F)
1916	39.4 C (102.9 F)
1917	37.8 C (100.0 F)
1918	43.3 C (109.9 F)
1919	36.7 C (98.1 F)
1920	36.1 C (97.0 F)
1921	37.8 C (100.0 F)
1922	38.3 C (100.9 F)
1923	37.8 C (100.0 F)
1924	36.1 C (97.0 F)
1925	39.4 C (102.9 F)
1926	38.3 C (100.9 F)
1927	37.8 C (100.0 F)
1928	35.6 C (96.1 F)
1929	36.7 C (98.1 F)
1930	41.1 C (106.0 F)
1931	42.2 C (108.0 F)
1932	37.8 C (100.0 F)
1933	39.4 C (102.9 F)
1934	43.9 C (111.0 F)
1935	38.3 C (100.9 F)
1936	44.4 C (111.9 F)
1937	38.3 C (100.9 F)
1938	38.9 C (102.0 F)
1939	40.6 C (105.1 F)
1940	41.7 C (107.1 F)
1941	40.6 C (105.1 F)
1942	36.7 C (98.1 F)
1943	35.0 C (95.0 F)
1944	35.6 C (96.1 F)
1945	37.2 C (99.0 F)
1946	35.0 C (95.0 F)
1947	38.3 C (100.9 F)
1948	36.1 C (97.0 F)
1949	35.0 C (95.0 F)
1950	11.1 C (52.0 F)

Coldest night (TNn)

The coldest night of the year at Afton, 1894 to 1950. The record is -34.4 C (-29.9 F) in 1912, marked on the chart; the median year is -25.6 C (-14.1 F).

Coldest night (TNn) at Afton by year
Year	Coldest night (TNn)
1894	-22.8 C (-9.0 F)
1895	-29.4 C (-20.9 F)
1896	-23.3 C (-9.9 F)
1897	-26.7 C (-16.1 F)
1898	-23.9 C (-11.0 F)
1899	-26.7 C (-16.1 F)
1900	-23.9 C (-11.0 F)
1901	-27.2 C (-17.0 F)
1902	-27.2 C (-17.0 F)
1903	-25.6 C (-14.1 F)
1904	-27.8 C (-18.0 F)
1905	-31.7 C (-25.1 F)
1906	-22.2 C (-8.0 F)
1907	-26.1 C (-15.0 F)
1908	-22.2 C (-8.0 F)
1909	-25.6 C (-14.1 F)
1910	-25.0 C (-13.0 F)
1911	-25.6 C (-14.1 F)
1912	-34.4 C (-29.9 F)
1913	-23.9 C (-11.0 F)
1914	-26.1 C (-15.0 F)
1915	-29.4 C (-20.9 F)
1916	-28.3 C (-18.9 F)
1917	-30.6 C (-23.1 F)
1918	-30.0 C (-22.0 F)
1919	-28.9 C (-20.0 F)
1920	-22.8 C (-9.0 F)
1921	-20.6 C (-5.1 F)
1922	-21.7 C (-7.1 F)
1923	-23.3 C (-9.9 F)
1924	-32.8 C (-27.0 F)
1925	-24.4 C (-11.9 F)
1926	-24.4 C (-11.9 F)
1927	-23.9 C (-11.0 F)
1928	-23.3 C (-9.9 F)
1929	-26.7 C (-16.1 F)
1930	-28.3 C (-18.9 F)
1931	-19.4 C (-2.9 F)
1932	-26.7 C (-16.1 F)
1933	-28.3 C (-18.9 F)
1934	-22.8 C (-9.0 F)
1935	-24.4 C (-11.9 F)
1936	-29.4 C (-20.9 F)
1937	-21.1 C (-6.0 F)
1938	-22.8 C (-9.0 F)
1939	-23.3 C (-9.9 F)
1940	-30.0 C (-22.0 F)
1941	-17.8 C (0.0 F)
1942	-28.9 C (-20.0 F)
1943	-28.3 C (-18.9 F)
1944	-27.2 C (-17.0 F)
1945	-24.4 C (-11.9 F)
1946	-22.8 C (-9.0 F)
1947	-24.4 C (-11.9 F)
1948	-28.9 C (-20.0 F)
1949	-26.1 C (-15.0 F)
1950	-23.3 C (-9.9 F)

Wettest day (Rx1day)

The wettest day of the year at Afton, 1894 to 1950. The record is 236.2 mm (9.3 in) in 1903, marked on the chart; the median year is 67.8 mm (2.7 in).

Wettest day (Rx1day) at Afton by year
Year	Wettest day (Rx1day)
1894	38.1 mm (1.5 in)
1895	111.8 mm (4.4 in)
1896	74.4 mm (2.9 in)
1897	100.6 mm (4.0 in)
1898	43.2 mm (1.7 in)
1899	53.3 mm (2.1 in)
1900	89.7 mm (3.5 in)
1901	47.0 mm (1.9 in)
1902	75.2 mm (3.0 in)
1903	236.2 mm (9.3 in)
1904	55.9 mm (2.2 in)
1905	53.6 mm (2.1 in)
1906	51.8 mm (2.0 in)
1907	55.6 mm (2.2 in)
1908	52.3 mm (2.1 in)
1909	81.0 mm (3.2 in)
1910	95.5 mm (3.8 in)
1911	50.8 mm (2.0 in)
1912	67.8 mm (2.7 in)
1913	53.6 mm (2.1 in)
1914	134.9 mm (5.3 in)
1915	96.0 mm (3.8 in)
1916	67.3 mm (2.6 in)
1917	52.1 mm (2.1 in)
1918	57.2 mm (2.3 in)
1919	76.2 mm (3.0 in)
1920	81.5 mm (3.2 in)
1921	76.7 mm (3.0 in)
1922	112.0 mm (4.4 in)
1923	39.6 mm (1.6 in)
1924	103.1 mm (4.1 in)
1925	64.8 mm (2.6 in)
1926	50.8 mm (2.0 in)
1927	53.8 mm (2.1 in)
1928	61.2 mm (2.4 in)
1929	39.4 mm (1.6 in)
1930	105.2 mm (4.1 in)
1931	85.1 mm (3.4 in)
1932	58.4 mm (2.3 in)
1933	106.9 mm (4.2 in)
1934	41.9 mm (1.6 in)
1935	84.6 mm (3.3 in)
1936	71.9 mm (2.8 in)
1937	54.6 mm (2.1 in)
1938	78.0 mm (3.1 in)
1939	44.5 mm (1.8 in)
1940	86.4 mm (3.4 in)
1941	85.1 mm (3.4 in)
1942	41.9 mm (1.6 in)
1943	77.5 mm (3.1 in)
1944	97.0 mm (3.8 in)
1945	45.5 mm (1.8 in)
1946	83.1 mm (3.3 in)
1947	70.9 mm (2.8 in)
1948	44.2 mm (1.7 in)
1949	109.7 mm (4.3 in)
1950	11.4 mm (0.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at Afton, 1894 to 1950. The record is 263.4 mm (10.4 in) in 1903, marked on the chart; the median year is 106.2 mm (4.2 in).

Wettest five days (Rx5day) at Afton by year
Year	Wettest five days (Rx5day)
1894	44.5 mm (1.8 in)
1895	129.1 mm (5.1 in)
1896	110.2 mm (4.3 in)
1897	165.0 mm (6.5 in)
1898	74.9 mm (2.9 in)
1899	93.4 mm (3.7 in)
1900	158.7 mm (6.2 in)
1901	93.2 mm (3.7 in)
1902	111.7 mm (4.4 in)
1903	263.4 mm (10.4 in)
1904	76.3 mm (3.0 in)
1905	85.1 mm (3.4 in)
1906	68.1 mm (2.7 in)
1907	78.0 mm (3.1 in)
1908	152.1 mm (6.0 in)
1909	148.1 mm (5.8 in)
1910	127.5 mm (5.0 in)
1911	91.0 mm (3.6 in)
1912	108.2 mm (4.3 in)
1913	81.4 mm (3.2 in)
1914	198.5 mm (7.8 in)
1915	259.8 mm (10.2 in)
1916	83.6 mm (3.3 in)
1917	150.1 mm (5.9 in)
1918	70.9 mm (2.8 in)
1919	156.2 mm (6.1 in)
1920	120.8 mm (4.8 in)
1921	143.0 mm (5.6 in)
1922	123.0 mm (4.8 in)
1923	77.7 mm (3.1 in)
1924	133.3 mm (5.2 in)
1925	77.0 mm (3.0 in)
1926	114.4 mm (4.5 in)
1927	104.6 mm (4.1 in)
1928	105.4 mm (4.1 in)
1929	62.3 mm (2.5 in)
1930	106.2 mm (4.2 in)
1931	101.8 mm (4.0 in)
1932	136.5 mm (5.4 in)
1933	114.8 mm (4.5 in)
1934	93.9 mm (3.7 in)
1935	113.6 mm (4.5 in)
1936	77.5 mm (3.1 in)
1937	67.8 mm (2.7 in)
1938	118.4 mm (4.7 in)
1939	91.5 mm (3.6 in)
1940	167.6 mm (6.6 in)
1941	121.4 mm (4.8 in)
1942	66.9 mm (2.6 in)
1943	118.6 mm (4.7 in)
1944	111.5 mm (4.4 in)
1945	76.8 mm (3.0 in)
1946	84.1 mm (3.3 in)
1947	84.3 mm (3.3 in)
1948	61.8 mm (2.4 in)
1949	149.3 mm (5.9 in)
1950	11.4 mm (0.4 in)

Longest dry spell (CDD)

The longest dry spell of the year at Afton, 1894 to 1950. The record is 52 days in 1904, marked on the chart; the median year is 27 days.

Longest dry spell (CDD) at Afton by year
Year	Longest dry spell (CDD)
1894	33 days
1895	31 days
1896	34 days
1897	23 days
1898	22 days
1899	31 days
1900	29 days
1901	29 days
1902	20 days
1903	33 days
1904	52 days
1905	26 days
1906	40 days
1907	25 days
1908	25 days
1909	25 days
1910	41 days
1911	29 days
1912	26 days
1913	27 days
1914	46 days
1915	26 days
1916	26 days
1917	34 days
1918	33 days
1919	31 days
1920	26 days
1921	34 days
1922	25 days
1923	18 days
1924	22 days
1925	36 days
1926	16 days
1927	22 days
1928	17 days
1929	21 days
1930	29 days
1931	34 days
1932	24 days
1933	32 days
1934	35 days
1935	18 days
1936	24 days
1937	27 days
1938	25 days
1939	37 days
1940	25 days
1941	18 days
1942	31 days
1943	20 days
1944	24 days
1945	24 days
1946	33 days
1947	35 days
1948	21 days
1949	27 days
1950	28 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

38 years with a frost

Across 38 years with a frost, the median last spring frost at Afton falls on 27 April and the median first autumn frost on 10 October, which leaves a median of 163 days between them.

Fitted over all years, the growing season changes by +2.0 days per decade at this station.

Frost dates and growing season at Afton
Measure	Median, all years	Earliest period	Recent period (1906 to 1948)	Recent against earliest	Fitted trend
Last spring frost	27 April	n/a	29 April	n/a	+0.4 days per decade
First autumn frost	10 October	n/a	11 October	n/a	+2.4 days per decade
Growing days	163 days	n/a	162 days	n/a	+2.0 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

48 years, 1895 to 1949

A day with at least 65.8 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 183.9 mm (7.2 in) of rain is expected about once in 100 years.

Rainfall return levels at Afton: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	65.8 mm (2.6 in)
5 years	90.5 mm (3.6 in)
10 years	109.3 mm (4.3 in)
25 years	136.3 mm (5.4 in)
50 years	158.9 mm (6.3 in)	Longer than the 48 years of record
100 years	183.9 mm (7.2 in)	Longer than the 48 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, 48 years of values from 1895 to 1949.

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: 236.2 mm (9.3 in) in 1903; 112.0 mm (4.4 in) in 1922; 111.8 mm (4.4 in) in 1895.

Download the Data

Data for Afton standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Afton 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).