Atikokan Cli Weather Records (CA006020381)

Record envelope, standing records and threshold days for Atikokan Cli (CA006020381), Ontario, Canada, with 58 years of record.

Key Facts for Atikokan Cli

Atikokan Cli (CA006020381) is a weather station in Ontario, Canada at 48.73 latitude and -91.63 longitude, 391 m (1,283 ft) above sea level.
The station reports from 1914 to 1971, 58 years of record.
1,464 records set at Atikokan Cli still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Atikokan Cli set a daily record high minimum temperature of 5.0 C (41.0 F) on 19 April 1971.

About the Station

Location: Ontario, Canada, 48.73 latitude, -91.63 longitude.
Elevation: 391 m (1,283 ft).
Period of record: 1914 to 1971, 58 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 Atikokan Cli. 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 Atikokan Cli, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	10.0 C (50.0 F)	-48.9 C (-56.0 F)	n/a	n/a
Feb	14.4 C (57.9 F)	-48.9 C (-56.0 F)	n/a	n/a
Mar	25.6 C (78.1 F)	-46.7 C (-52.1 F)	n/a	n/a
Apr	32.2 C (90.0 F)	-32.2 C (-26.0 F)	n/a	n/a
May	35.0 C (95.0 F)	-13.9 C (7.0 F)	n/a	n/a
Jun	37.8 C (100.0 F)	-6.1 C (21.0 F)	n/a	n/a
Jul	42.2 C (108.0 F)	-2.2 C (28.0 F)	n/a	n/a
Aug	35.0 C (95.0 F)	-6.7 C (19.9 F)	n/a	n/a
Sep	37.2 C (99.0 F)	-11.7 C (10.9 F)	n/a	n/a
Oct	30.0 C (86.0 F)	-28.9 C (-20.0 F)	n/a	n/a
Nov	21.1 C (70.0 F)	-39.4 C (-38.9 F)	n/a	n/a
Dec	11.1 C (52.0 F)	-46.1 C (-51.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Atikokan Cli still stand. 1925 holds the most, with 69.

Standing records at Atikokan Cli by the year they were set
Year set	Standing records
1914	10
1915	39
1917	43
1918	25
1919	44
1920	38
1921	27
1922	36
1923	34
1924	47
1925	69
1926	23
1927	20
1928	43
1929	33
1930	36
1931	40
1932	37
1933	26
1934	34
1935	28
1936	54
1937	22
1938	20
1939	33
1940	25
1941	19
1942	28
1943	25
1944	16
1945	28
1946	30
1947	30
1948	11
1949	13
1950	15
1951	20
1952	25
1953	33
1954	18
1955	19
1956	19
1957	7
1958	30
1959	11
1960	9
1961	5
1962	19
1963	21
1964	23
1965	12
1966	19
1967	12
1968	22
1969	15
1970	18
1971	6

Wettest Day of Each Month

Oct: 92.7 mm (3.6 in)

The wettest day on record for each calendar month at Atikokan Cli. The most was 92.7 mm (3.6 in) on 5 October 1946.

Record daily precipitation for each month at Atikokan Cli
Month	Record daily precipitation (mm)	Date
Jan	20.3 mm (0.8 in)	14 January 1953
Feb	20.3 mm (0.8 in)	13 February 1938
Mar	30.5 mm (1.2 in)	12 March 1936
Apr	65.3 mm (2.6 in)	29 April 1940
May	50.8 mm (2.0 in)	18 May 1933
Jun	76.2 mm (3.0 in)	20 June 1926
Jul	63.5 mm (2.5 in)	9 July 1934
Aug	76.2 mm (3.0 in)	6 August 1933
Sep	80.8 mm (3.2 in)	21 September 1941
Oct	92.7 mm (3.6 in)	5 October 1946
Nov	52.8 mm (2.1 in)	20 November 1934
Dec	16.5 mm (0.6 in)	15 December 1927

Period of Record Coverage

1914 to 1971

57 years of record at Atikokan Cli, 1914 to 1971. 6 years have data for under 90 percent of days and are left out of rankings: 1914, 1915, 1918, 1924, 1964, 1971.

Days with data per year at Atikokan Cli
Year	Days with data	Share of year	Complete
1914	69	19%	No
1915	196	54%	No
1917	334	92%	Yes
1918	242	66%	No
1919	365	100%	Yes
1920	366	100%	Yes
1921	365	100%	Yes
1922	365	100%	Yes
1923	348	95%	Yes
1924	273	75%	No
1925	335	92%	Yes
1926	334	92%	Yes
1927	362	99%	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	364	100%	Yes
1935	365	100%	Yes
1936	366	100%	Yes
1937	365	100%	Yes
1938	365	100%	Yes
1939	365	100%	Yes
1940	366	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	365	100%	Yes
1948	366	100%	Yes
1949	365	100%	Yes
1950	334	92%	Yes
1951	365	100%	Yes
1952	366	100%	Yes
1953	365	100%	Yes
1954	365	100%	Yes
1955	334	92%	Yes
1956	365	100%	Yes
1957	365	100%	Yes
1958	365	100%	Yes
1959	365	100%	Yes
1960	366	100%	Yes
1961	364	100%	Yes
1962	329	90%	Yes
1963	349	96%	Yes
1964	325	89%	No
1965	334	92%	Yes
1966	362	99%	Yes
1967	359	98%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	356	98%	Yes
1971	181	50%	No

Latest Records

Latest records at Atikokan Cli
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
19 April 1971	Atikokan Cli, CA	daily high min	5.0 C (41.0 F)	0.6 C (1.1 F)	52 years	20 of 100 (Routine)
11 April 1971	Atikokan Cli, CA	daily high min	8.3 C (46.9 F)	6.6 C (11.9 F)	44 years	28 of 100 (Routine)
8 April 1971	Atikokan Cli, CA	daily high min (Tie)	1.7 C (35.1 F)	tie	25 years	3 of 100 (Routine)
4 April 1971	Atikokan Cli, CA	daily low min	-26.1 C (-15.0 F)	3.9 C (7.0 F)	50 years	26 of 100 (Routine)
27 February 1971	Atikokan Cli, CA	daily rain	12.7 mm (0.5 in)	5.1 mm (0.20 in)	31 years	20 of 100 (Routine)
27 February 1971	Atikokan Cli, CA	daily snowfall	12.7 cm (5.0 in)	5.1 cm (2.0 in)	31 years	29 of 100 (Routine)
25 February 1971	Atikokan Cli, CA	daily high max	10.6 C (51.1 F)	0.6 C (1.1 F)	39 years	16 of 100 (Routine)
16 February 1971	Atikokan Cli, CA	daily high min	-5.0 C (23.0 F)	0.6 C (1.1 F)	31 years	14 of 100 (Routine)
15 February 1971	Atikokan Cli, CA	daily high min	-6.1 C (21.0 F)	0.6 C (1.1 F)	36 years	15 of 100 (Routine)
26 December 1970	Atikokan Cli, CA	daily rain	10.2 mm (0.4 in)	2.6 mm (0.10 in)	0 years	11 of 100 (Routine)
26 December 1970	Atikokan Cli, CA	daily snowfall	10.2 cm (4.0 in)	2.6 cm (1.0 in)	0 years	11 of 100 (Routine)
1 December 1970	Atikokan Cli, CA	daily high min	-2.8 C (27.0 F)	1.1 C (2.0 F)	48 years	20 of 100 (Routine)
23 November 1970	Atikokan Cli, CA	daily low max	-11.1 C (12.0 F)	0.5 C (0.9 F)	44 years	18 of 100 (Routine)
19 November 1970	Atikokan Cli, CA	daily high min (Tie)	-1.1 C (30.0 F)	tie	40 years	4 of 100 (Routine)
29 September 1970	Atikokan Cli, CA	daily high min	8.3 C (46.9 F)	0.5 C (0.9 F)	48 years	19 of 100 (Routine)
21 September 1970	Atikokan Cli, CA	daily high min	15.6 C (60.1 F)	0.6 C (1.1 F)	28 years	14 of 100 (Routine)
20 September 1970	Atikokan Cli, CA	daily high min	17.2 C (63.0 F)	2.2 C (4.0 F)	8 years	11 of 100 (Routine)
7 September 1970	Atikokan Cli, CA	daily high min	20.0 C (68.0 F)	5.6 C (10.1 F)	29 years	23 of 100 (Routine)
3 September 1970	Atikokan Cli, CA	daily high min	17.8 C (64.0 F)	2.8 C (5.0 F)	9 years	12 of 100 (Routine)
3 September 1970	Atikokan Cli, CA	daily rain (Tie)	25.4 mm (1.0 in)	tie	55 years	5 of 100 (Routine)

Climate Trend

37 complete years, 1919 to 1970

One stripe for each of 37 complete years at Atikokan Cli, 1919 to 1970. Blue stripes are years cooler than the station's own mean of 1.9 C (35.3 F); red stripes are warmer. The coolest year was 1957, at 0.5 C (32.8 F), and the warmest was 1931, at 4.4 C (39.9 F). The strongest colour marks a difference of 2.6 C (4.7 F).

Annual mean temperature at Atikokan Cli as warming stripes, 1919 to 1970
Year	Annual mean temperature	Difference from the station mean
1919	1.9 C	+0.01 C
1920	2.1 C	+0.29 C
1921	3.7 C	+1.80 C
1922	3.0 C	+1.16 C
1927	1.2 C	-0.68 C
1928	1.9 C	+0.07 C
1929	0.6 C	-1.23 C
1930	2.1 C	+0.21 C
1931	4.4 C	+2.52 C
1932	1.4 C	-0.50 C
1933	1.2 C	-0.66 C
1934	1.3 C	-0.51 C
1935	1.8 C	-0.09 C
1936	0.9 C	-0.97 C
1937	0.8 C	-1.05 C
1938	2.0 C	+0.17 C
1939	1.6 C	-0.29 C
1940	1.3 C	-0.58 C
1941	3.1 C	+1.25 C
1942	1.5 C	-0.37 C
1947	1.4 C	-0.49 C
1948	2.0 C	+0.14 C
1949	2.2 C	+0.30 C
1951	1.3 C	-0.52 C
1952	2.9 C	+1.01 C
1953	3.1 C	+1.28 C
1956	1.1 C	-0.78 C
1957	0.5 C	-1.38 C
1958	0.8 C	-1.04 C
1959	0.8 C	-1.06 C
1961	3.0 C	+1.19 C
1963	2.6 C	+0.79 C
1966	1.5 C	-0.31 C
1967	1.2 C	-0.63 C
1968	2.6 C	+0.76 C
1969	2.2 C	+0.36 C
1970	1.8 C	-0.01 C

The fitted trend in annual mean temperature here over 1919 to 1970 is -0.1 C (-0.3 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.5 to 0.3) per decade. The slope is a straight line fitted to 37 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Atikokan Cli
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.1 C (-0.3 to 0.1) per decade	-0.1 F (-0.5 to 0.3) per decade	1919 to 1970	37	Not clearly different from zero
Mean daily maximum	-0.17 C (-0.36 to 0.02) per decade	-0.30 F (-0.65 to 0.04) per decade	1919 to 1970	37	Not clearly different from zero
Mean daily minimum	0.1 C (-0.2 to 0.3) per decade	0.1 F (-0.4 to 0.6) per decade	1919 to 1970	37	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

1914 to 1971

Yearly extremes at Atikokan Cli: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	42.2 C (108.0 F)	1936	33.3 C (91.9 F)	57
Coldest night (TNn)	-48.9 C (-56.0 F)	1939	-43.9 C (-47.0 F)	57
Wettest day (Rx1day)	92.7 mm (3.6 in)	1946	38.1 mm (1.5 in)	57
Wettest five days (Rx5day)	134.1 mm (5.3 in)	1941	54.6 mm (2.1 in)	57
Longest dry spell (CDD)	34 days	1958	21 days	57

Hottest day (TXx)

The hottest day of the year at Atikokan Cli, 1914 to 1971. The record is 42.2 C (108.0 F) in 1936, marked on the chart; the median year is 33.3 C (91.9 F).

Hottest day (TXx) at Atikokan Cli by year
Year	Hottest day (TXx)
1914	32.2 C (90.0 F)
1915	36.7 C (98.1 F)
1917	36.1 C (97.0 F)
1918	31.7 C (89.1 F)
1919	35.0 C (95.0 F)
1920	33.9 C (93.0 F)
1921	36.7 C (98.1 F)
1922	34.4 C (93.9 F)
1923	33.3 C (91.9 F)
1924	26.7 C (80.1 F)
1925	32.2 C (90.0 F)
1926	32.8 C (91.0 F)
1927	32.2 C (90.0 F)
1928	31.1 C (88.0 F)
1929	36.7 C (98.1 F)
1930	34.4 C (93.9 F)
1931	37.8 C (100.0 F)
1932	35.0 C (95.0 F)
1933	37.2 C (99.0 F)
1934	32.8 C (91.0 F)
1935	33.9 C (93.0 F)
1936	42.2 C (108.0 F)
1937	34.4 C (93.9 F)
1938	31.7 C (89.1 F)
1939	34.4 C (93.9 F)
1940	35.6 C (96.1 F)
1941	35.0 C (95.0 F)
1942	31.1 C (88.0 F)
1943	33.3 C (91.9 F)
1944	31.7 C (89.1 F)
1945	33.3 C (91.9 F)
1946	32.2 C (90.0 F)
1947	34.4 C (93.9 F)
1948	35.6 C (96.1 F)
1949	34.4 C (93.9 F)
1950	32.2 C (90.0 F)
1951	32.8 C (91.0 F)
1952	32.8 C (91.0 F)
1953	35.0 C (95.0 F)
1954	32.2 C (90.0 F)
1955	34.4 C (93.9 F)
1956	34.4 C (93.9 F)
1957	31.1 C (88.0 F)
1958	31.7 C (89.1 F)
1959	33.9 C (93.0 F)
1960	30.6 C (87.1 F)
1961	33.3 C (91.9 F)
1962	30.6 C (87.1 F)
1963	32.2 C (90.0 F)
1964	32.8 C (91.0 F)
1965	30.6 C (87.1 F)
1966	35.0 C (95.0 F)
1967	31.7 C (89.1 F)
1968	30.0 C (86.0 F)
1969	33.9 C (93.0 F)
1970	32.2 C (90.0 F)
1971	29.4 C (84.9 F)

Coldest night (TNn)

The coldest night of the year at Atikokan Cli, 1914 to 1971. The record is -48.9 C (-56.0 F) in 1939, marked on the chart; the median year is -43.9 C (-47.0 F).

Coldest night (TNn) at Atikokan Cli by year
Year	Coldest night (TNn)
1914	-6.7 C (19.9 F)
1915	-40.0 C (-40.0 F)
1917	-45.6 C (-50.1 F)
1918	-44.4 C (-47.9 F)
1919	-43.9 C (-47.0 F)
1920	-41.7 C (-43.1 F)
1921	-41.1 C (-42.0 F)
1922	-44.4 C (-47.9 F)
1923	-44.4 C (-47.9 F)
1924	-41.1 C (-42.0 F)
1925	-43.3 C (-45.9 F)
1926	-41.1 C (-42.0 F)
1927	-44.4 C (-47.9 F)
1928	-41.1 C (-42.0 F)
1929	-42.8 C (-45.0 F)
1930	-45.0 C (-49.0 F)
1931	-40.0 C (-40.0 F)
1932	-45.6 C (-50.1 F)
1933	-48.3 C (-54.9 F)
1934	-47.2 C (-53.0 F)
1935	-45.6 C (-50.1 F)
1936	-43.9 C (-47.0 F)
1937	-45.6 C (-50.1 F)
1938	-46.7 C (-52.1 F)
1939	-48.9 C (-56.0 F)
1940	-43.9 C (-47.0 F)
1941	-43.3 C (-45.9 F)
1942	-45.0 C (-49.0 F)
1943	-48.9 C (-56.0 F)
1944	-42.8 C (-45.0 F)
1945	-44.4 C (-47.9 F)
1946	-46.1 C (-51.0 F)
1947	-44.4 C (-47.9 F)
1948	-42.8 C (-45.0 F)
1949	-41.1 C (-42.0 F)
1950	-46.7 C (-52.1 F)
1951	-45.6 C (-50.1 F)
1952	-40.0 C (-40.0 F)
1953	-42.8 C (-45.0 F)
1954	-44.4 C (-47.9 F)
1955	-43.3 C (-45.9 F)
1956	-40.0 C (-40.0 F)
1957	-47.2 C (-53.0 F)
1958	-43.9 C (-47.0 F)
1959	-43.9 C (-47.0 F)
1960	-35.6 C (-32.1 F)
1961	-41.7 C (-43.1 F)
1962	-42.8 C (-45.0 F)
1963	-43.9 C (-47.0 F)
1964	-40.0 C (-40.0 F)
1965	-42.2 C (-44.0 F)
1966	-43.9 C (-47.0 F)
1967	-43.9 C (-47.0 F)
1968	-41.7 C (-43.1 F)
1969	-39.4 C (-38.9 F)
1970	-42.2 C (-44.0 F)
1971	-35.6 C (-32.1 F)

Wettest day (Rx1day)

The wettest day of the year at Atikokan Cli, 1914 to 1971. The record is 92.7 mm (3.6 in) in 1946, marked on the chart; the median year is 38.1 mm (1.5 in).

Wettest day (Rx1day) at Atikokan Cli by year
Year	Wettest day (Rx1day)
1914	28.4 mm (1.1 in)
1915	58.4 mm (2.3 in)
1917	20.3 mm (0.8 in)
1918	35.6 mm (1.4 in)
1919	27.7 mm (1.1 in)
1920	65.3 mm (2.6 in)
1921	33.5 mm (1.3 in)
1922	39.4 mm (1.6 in)
1923	54.6 mm (2.1 in)
1924	45.2 mm (1.8 in)
1925	38.1 mm (1.5 in)
1926	76.2 mm (3.0 in)
1927	39.4 mm (1.6 in)
1928	39.4 mm (1.6 in)
1929	23.6 mm (0.9 in)
1930	32.8 mm (1.3 in)
1931	38.9 mm (1.5 in)
1932	59.2 mm (2.3 in)
1933	76.2 mm (3.0 in)
1934	63.5 mm (2.5 in)
1935	55.1 mm (2.2 in)
1936	30.5 mm (1.2 in)
1937	53.3 mm (2.1 in)
1938	47.5 mm (1.9 in)
1939	55.9 mm (2.2 in)
1940	65.3 mm (2.6 in)
1941	80.8 mm (3.2 in)
1942	34.5 mm (1.4 in)
1943	54.6 mm (2.1 in)
1944	71.6 mm (2.8 in)
1945	27.2 mm (1.1 in)
1946	92.7 mm (3.6 in)
1947	46.2 mm (1.8 in)
1948	38.1 mm (1.5 in)
1949	41.1 mm (1.6 in)
1950	38.1 mm (1.5 in)
1951	25.4 mm (1.0 in)
1952	31.8 mm (1.3 in)
1953	21.1 mm (0.8 in)
1954	25.4 mm (1.0 in)
1955	26.7 mm (1.1 in)
1956	29.0 mm (1.1 in)
1957	38.1 mm (1.5 in)
1958	16.0 mm (0.6 in)
1959	32.5 mm (1.3 in)
1960	32.0 mm (1.3 in)
1961	27.9 mm (1.1 in)
1962	15.2 mm (0.6 in)
1963	30.5 mm (1.2 in)
1964	40.6 mm (1.6 in)
1965	25.4 mm (1.0 in)
1966	40.1 mm (1.6 in)
1967	12.7 mm (0.5 in)
1968	20.3 mm (0.8 in)
1969	26.7 mm (1.1 in)
1970	27.9 mm (1.1 in)
1971	12.7 mm (0.5 in)

Wettest five days (Rx5day)

The wettest five days of the year at Atikokan Cli, 1914 to 1971. The record is 134.1 mm (5.3 in) in 1941, marked on the chart; the median year is 54.6 mm (2.1 in).

Wettest five days (Rx5day) at Atikokan Cli by year
Year	Wettest five days (Rx5day)
1914	56.1 mm (2.2 in)
1915	78.7 mm (3.1 in)
1917	29.2 mm (1.1 in)
1918	39.4 mm (1.6 in)
1919	52.1 mm (2.1 in)
1920	71.1 mm (2.8 in)
1921	60.2 mm (2.4 in)
1922	45.0 mm (1.8 in)
1923	99.1 mm (3.9 in)
1924	55.3 mm (2.2 in)
1925	46.2 mm (1.8 in)
1926	100.6 mm (4.0 in)
1927	55.4 mm (2.2 in)
1928	65.6 mm (2.6 in)
1929	36.4 mm (1.4 in)
1930	43.7 mm (1.7 in)
1931	57.2 mm (2.3 in)
1932	70.6 mm (2.8 in)
1933	81.8 mm (3.2 in)
1934	67.3 mm (2.6 in)
1935	85.3 mm (3.4 in)
1936	46.2 mm (1.8 in)
1937	75.7 mm (3.0 in)
1938	71.2 mm (2.8 in)
1939	81.3 mm (3.2 in)
1940	83.0 mm (3.3 in)
1941	134.1 mm (5.3 in)
1942	54.6 mm (2.1 in)
1943	76.4 mm (3.0 in)
1944	84.7 mm (3.3 in)
1945	56.9 mm (2.2 in)
1946	92.7 mm (3.6 in)
1947	83.8 mm (3.3 in)
1948	50.3 mm (2.0 in)
1949	57.1 mm (2.2 in)
1950	48.2 mm (1.9 in)
1951	43.9 mm (1.7 in)
1952	31.8 mm (1.3 in)
1953	38.4 mm (1.5 in)
1954	63.6 mm (2.5 in)
1955	54.6 mm (2.1 in)
1956	45.9 mm (1.8 in)
1957	46.7 mm (1.8 in)
1958	26.5 mm (1.0 in)
1959	34.6 mm (1.4 in)
1960	40.4 mm (1.6 in)
1961	44.4 mm (1.7 in)
1962	30.5 mm (1.2 in)
1963	62.4 mm (2.5 in)
1964	42.4 mm (1.7 in)
1965	41.6 mm (1.6 in)
1966	41.4 mm (1.6 in)
1967	29.4 mm (1.2 in)
1968	28.6 mm (1.1 in)
1969	36.3 mm (1.4 in)
1970	39.3 mm (1.5 in)
1971	20.3 mm (0.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Atikokan Cli, 1914 to 1971. The record is 34 days in 1958, marked on the chart; the median year is 21 days.

Longest dry spell (CDD) at Atikokan Cli by year
Year	Longest dry spell (CDD)
1914	15 days
1915	25 days
1917	17 days
1918	18 days
1919	25 days
1920	30 days
1921	18 days
1922	19 days
1923	28 days
1924	19 days
1925	23 days
1926	18 days
1927	19 days
1928	30 days
1929	18 days
1930	17 days
1931	33 days
1932	19 days
1933	14 days
1934	23 days
1935	19 days
1936	24 days
1937	16 days
1938	21 days
1939	21 days
1940	20 days
1941	25 days
1942	33 days
1943	21 days
1944	28 days
1945	23 days
1946	21 days
1947	23 days
1948	26 days
1949	22 days
1950	20 days
1951	16 days
1952	26 days
1953	25 days
1954	14 days
1955	16 days
1956	22 days
1957	25 days
1958	34 days
1959	21 days
1960	23 days
1961	25 days
1962	28 days
1963	20 days
1964	17 days
1965	17 days
1966	16 days
1967	20 days
1968	20 days
1969	31 days
1970	16 days
1971	14 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

37 years with a frost

Across 37 years with a frost, the median last spring frost at Atikokan Cli falls on 14 June and the median first autumn frost on 27 August, which leaves a median of 73 days between them.

Fitted over all years, the growing season changes by +5.4 days per decade at this station.

Frost dates and growing season at Atikokan Cli
Measure	Median, all years	Earliest period	Recent period (1930 to 1970)	Recent against earliest	Fitted trend
Last spring frost	14 June	n/a	15 June	n/a	-1.0 days per decade
First autumn frost	27 August	n/a	27 August	n/a	+4.4 days per decade
Growing days	73 days	n/a	73 days	n/a	+5.4 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

42 years, 1919 to 1970

A day with at least 40.7 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 107.4 mm (4.2 in) of rain is expected about once in 100 years.

Rainfall return levels at Atikokan Cli: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	40.7 mm (1.6 in)
5 years	57.2 mm (2.3 in)
10 years	68.7 mm (2.7 in)
25 years	83.8 mm (3.3 in)
50 years	95.4 mm (3.8 in)	Longer than the 42 years of record
100 years	107.4 mm (4.2 in)	Longer than the 42 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, 42 years of values from 1919 to 1970.

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: 92.7 mm (3.6 in) in 1946; 80.8 mm (3.2 in) in 1941; 76.2 mm (3.0 in) in 1926.

Download the Data

Data for Atikokan Cli standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Atikokan Cli 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 2026-10-17. Last revised 17 October 2026 (2026-10-17).