Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Sioux Lookout A. 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 Sioux Lookout A, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
6.7 C (44.1 F)
-45.0 C (-49.0 F)
n/a
n/a
Feb
8.9 C (48.0 F)
-46.1 C (-51.0 F)
n/a
n/a
Mar
18.9 C (66.0 F)
-37.8 C (-36.0 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-30.0 C (-22.0 F)
n/a
n/a
May
33.1 C (91.6 F)
-15.6 C (3.9 F)
n/a
n/a
Jun
35.0 C (95.0 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
36.1 C (97.0 F)
1.1 C (34.0 F)
n/a
n/a
Aug
35.6 C (96.1 F)
0.0 C (32.0 F)
n/a
n/a
Sep
35.0 C (95.0 F)
-6.1 C (21.0 F)
n/a
n/a
Oct
26.7 C (80.1 F)
-16.1 C (3.0 F)
n/a
n/a
Nov
18.9 C (66.0 F)
-33.9 C (-29.0 F)
n/a
n/a
Dec
8.9 C (48.0 F)
-41.1 C (-42.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Sioux Lookout A still stand. 1939 holds the most, with 49.
Standing records at Sioux Lookout A by the year they were set
Year set
Standing records
1938
14
1939
49
1940
38
1941
44
1942
40
1943
43
1944
24
1945
45
1946
41
1947
33
1948
25
1949
32
1950
36
1951
39
1952
38
1953
38
1954
28
1955
26
1956
45
1957
14
1958
44
1959
27
1960
13
1961
16
1962
28
1963
41
1964
41
1965
22
1966
34
1967
35
1968
30
1969
40
1970
12
1971
13
1972
35
1973
24
1974
30
1975
34
1976
41
1977
40
1978
12
1979
24
1980
28
1981
40
1982
31
1983
37
All-Time Record Progression
3 new records
3 all-time records were set at Sioux Lookout A between 14 January 1972 and 30 July 1975. Each dot is a new record.
When Sioux Lookout A set new all-time records
Date
Kind
Detail
1972-01-14
Record low maximum temperature
Record low maximum temperature -35.6 C (-32.1 F)
1975-07-17
Record high minimum temperature
Record high minimum temperature 24.4 C (75.9 F)
1975-07-30
Record high maximum temperature
Record high maximum temperature 36.1 C (97.0 F)
Wettest Day of Each Month
Sep: 115.8 mm (4.6 in)
The wettest day on record for each calendar month at Sioux Lookout A. The most was 115.8 mm (4.6 in) on 20 September 1941.
Record daily precipitation for each month at Sioux Lookout A
Month
Record daily precipitation (mm)
Date
Jan
25.9 mm (1.0 in)
11 January 1975
Feb
32.5 mm (1.3 in)
27 February 1971
Mar
29.4 mm (1.2 in)
31 March 1978
Apr
31.5 mm (1.2 in)
8 April 1962
May
56.4 mm (2.2 in)
16 May 1968
Jun
78.7 mm (3.1 in)
29 June 1941
Jul
69.9 mm (2.8 in)
18 July 1961
Aug
47.5 mm (1.9 in)
22 August 1962
Sep
115.8 mm (4.6 in)
20 September 1941
Oct
60.2 mm (2.4 in)
2 October 1951
Nov
40.6 mm (1.6 in)
16 November 1941
Dec
23.1 mm (0.9 in)
31 December 1965
Period of Record Coverage
1938 to 1983
Complete yearUnder 90 percent of days
46 years of record at Sioux Lookout A, 1938 to 1983. 1 years have data for under 90 percent of days and are left out of rankings: 1938.
Cooler than the station meanWarmer than the station mean
One stripe for each of 44 complete years at Sioux Lookout A, 1939 to 1983. Blue stripes are years cooler than the station's own mean of 1.2 C (34.1 F); red stripes are warmer. The coolest year was 1950, at -1.1 C (30.1 F), and the warmest was 1981, at 2.9 C (37.2 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Sioux Lookout A as warming stripes, 1939 to 1983
Year
Annual mean temperature
Difference from the station mean
1939
1.4 C
+0.18 C
1940
1.5 C
+0.36 C
1941
2.6 C
+1.45 C
1942
1.9 C
+0.76 C
1943
0.6 C
-0.53 C
1944
2.1 C
+0.88 C
1945
0.7 C
-0.43 C
1946
1.5 C
+0.28 C
1947
1.1 C
-0.04 C
1948
1.9 C
+0.69 C
1949
1.4 C
+0.18 C
1950
-1.1 C
-2.24 C
1951
0.4 C
-0.79 C
1952
2.2 C
+1.04 C
1953
2.3 C
+1.08 C
1954
1.3 C
+0.14 C
1955
1.8 C
+0.59 C
1956
0.9 C
-0.26 C
1957
1.1 C
-0.04 C
1958
1.3 C
+0.09 C
1959
0.8 C
-0.35 C
1960
1.3 C
+0.10 C
1961
2.2 C
+1.00 C
1962
1.1 C
-0.09 C
1963
1.4 C
+0.27 C
1964
0.9 C
-0.23 C
1965
0.1 C
-1.05 C
1966
0.0 C
-1.16 C
1967
0.0 C
-1.15 C
1968
0.9 C
-0.26 C
1969
1.1 C
-0.11 C
1970
0.7 C
-0.46 C
1971
1.0 C
-0.20 C
1972
-0.4 C
-1.61 C
1973
2.2 C
+1.01 C
1974
0.5 C
-0.72 C
1975
1.6 C
+0.43 C
1976
0.8 C
-0.42 C
1977
1.9 C
+0.71 C
1978
0.2 C
-0.94 C
1980
1.0 C
-0.15 C
1981
2.9 C
+1.72 C
1982
0.4 C
-0.78 C
1983
2.4 C
+1.19 C
The fitted trend in annual mean temperature here over 1939 to 1983 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: -0.2 F (-0.5 to 0.2) per decade. The slope is a straight line fitted to 44 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Sioux Lookout A
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.3 to 0.1) per decade
-0.2 F (-0.5 to 0.2) per decade
1939 to 1983
44
Not clearly different from zero
Mean daily maximum
0.01 C (-0.18 to 0.20) per decade
0.01 F (-0.33 to 0.35) per decade
1939 to 1983
44
Not clearly different from zero
Mean daily minimum
-0.17 C (-0.39 to 0.04) per decade
-0.3 F (-0.7 to 0.1) per decade
1939 to 1983
44
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
1938 to 1983
Yearly extremes at Sioux Lookout A: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.1 C (97.0 F)
1975
32.8 C (91.0 F)
46
Coldest night (TNn)
-46.1 C (-51.0 F)
1966
-39.2 C (-38.6 F)
46
Wettest day (Rx1day)
115.8 mm (4.6 in)
1941
39.8 mm (1.6 in)
46
Wettest five days (Rx5day)
184.1 mm (7.2 in)
1941
64.8 mm (2.6 in)
46
Longest dry spell (CDD)
32 days
1972
17 days
46
Hottest day (TXx)
The hottest day of the year at Sioux Lookout A, 1938 to 1983. The record is 36.1 C (97.0 F) in 1975, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Sioux Lookout A by year
Year
Hottest day (TXx)
1938
29.4 C (84.9 F)
1939
31.1 C (88.0 F)
1940
35.0 C (95.0 F)
1941
35.0 C (95.0 F)
1942
31.7 C (89.1 F)
1943
33.3 C (91.9 F)
1944
31.1 C (88.0 F)
1945
33.9 C (93.0 F)
1946
31.1 C (88.0 F)
1947
35.6 C (96.1 F)
1948
32.8 C (91.0 F)
1949
35.0 C (95.0 F)
1950
30.6 C (87.1 F)
1951
32.2 C (90.0 F)
1952
33.9 C (93.0 F)
1953
31.1 C (88.0 F)
1954
30.6 C (87.1 F)
1955
34.4 C (93.9 F)
1956
35.0 C (95.0 F)
1957
33.3 C (91.9 F)
1958
32.8 C (91.0 F)
1959
32.2 C (90.0 F)
1960
31.7 C (89.1 F)
1961
32.2 C (90.0 F)
1962
31.7 C (89.1 F)
1963
32.8 C (91.0 F)
1964
32.8 C (91.0 F)
1965
30.0 C (86.0 F)
1966
33.3 C (91.9 F)
1967
32.8 C (91.0 F)
1968
30.0 C (86.0 F)
1969
32.8 C (91.0 F)
1970
32.8 C (91.0 F)
1971
30.6 C (87.1 F)
1972
30.6 C (87.1 F)
1973
31.7 C (89.1 F)
1974
31.7 C (89.1 F)
1975
36.1 C (97.0 F)
1976
35.0 C (95.0 F)
1977
31.0 C (87.8 F)
1978
30.9 C (87.6 F)
1979
33.1 C (91.6 F)
1980
33.1 C (91.6 F)
1981
33.7 C (92.7 F)
1982
31.1 C (88.0 F)
1983
35.7 C (96.3 F)
Coldest night (TNn)
The coldest night of the year at Sioux Lookout A, 1938 to 1983. The record is -46.1 C (-51.0 F) in 1966, marked on the chart; the median year is -39.2 C (-38.6 F).
Coldest night (TNn) at Sioux Lookout A by year
Year
Coldest night (TNn)
1938
-36.7 C (-34.1 F)
1939
-39.4 C (-38.9 F)
1940
-37.8 C (-36.0 F)
1941
-38.9 C (-38.0 F)
1942
-39.4 C (-38.9 F)
1943
-43.3 C (-45.9 F)
1944
-34.4 C (-29.9 F)
1945
-38.9 C (-38.0 F)
1946
-37.2 C (-35.0 F)
1947
-37.8 C (-36.0 F)
1948
-37.8 C (-36.0 F)
1949
-42.2 C (-44.0 F)
1950
-41.7 C (-43.1 F)
1951
-41.7 C (-43.1 F)
1952
-35.0 C (-31.0 F)
1953
-40.0 C (-40.0 F)
1954
-37.8 C (-36.0 F)
1955
-39.4 C (-38.9 F)
1956
-33.9 C (-29.0 F)
1957
-41.7 C (-43.1 F)
1958
-38.3 C (-36.9 F)
1959
-37.8 C (-36.0 F)
1960
-34.4 C (-29.9 F)
1961
-38.3 C (-36.9 F)
1962
-38.3 C (-36.9 F)
1963
-43.3 C (-45.9 F)
1964
-38.9 C (-38.0 F)
1965
-41.1 C (-42.0 F)
1966
-46.1 C (-51.0 F)
1967
-41.7 C (-43.1 F)
1968
-43.3 C (-45.9 F)
1969
-34.4 C (-29.9 F)
1970
-38.3 C (-36.9 F)
1971
-37.2 C (-35.0 F)
1972
-41.1 C (-42.0 F)
1973
-41.1 C (-42.0 F)
1974
-45.0 C (-49.0 F)
1975
-39.4 C (-38.9 F)
1976
-39.4 C (-38.9 F)
1977
-39.5 C (-39.1 F)
1978
-35.6 C (-32.1 F)
1979
-39.4 C (-38.9 F)
1980
-35.7 C (-32.3 F)
1981
-42.0 C (-43.6 F)
1982
-43.2 C (-45.8 F)
1983
-39.0 C (-38.2 F)
Wettest day (Rx1day)
The wettest day of the year at Sioux Lookout A, 1938 to 1983. The record is 115.8 mm (4.6 in) in 1941, marked on the chart; the median year is 39.8 mm (1.6 in).
Wettest day (Rx1day) at Sioux Lookout A by year
Year
Wettest day (Rx1day)
1938
24.9 mm (1.0 in)
1939
55.6 mm (2.2 in)
1940
27.9 mm (1.1 in)
1941
115.8 mm (4.6 in)
1942
36.6 mm (1.4 in)
1943
75.9 mm (3.0 in)
1944
36.3 mm (1.4 in)
1945
41.4 mm (1.6 in)
1946
48.3 mm (1.9 in)
1947
33.5 mm (1.3 in)
1948
28.2 mm (1.1 in)
1949
29.5 mm (1.2 in)
1950
49.5 mm (1.9 in)
1951
60.2 mm (2.4 in)
1952
29.7 mm (1.2 in)
1953
33.0 mm (1.3 in)
1954
35.6 mm (1.4 in)
1955
46.0 mm (1.8 in)
1956
26.4 mm (1.0 in)
1957
42.2 mm (1.7 in)
1958
34.8 mm (1.4 in)
1959
37.8 mm (1.5 in)
1960
20.3 mm (0.8 in)
1961
69.9 mm (2.8 in)
1962
47.5 mm (1.9 in)
1963
50.5 mm (2.0 in)
1964
45.7 mm (1.8 in)
1965
25.7 mm (1.0 in)
1966
50.3 mm (2.0 in)
1967
43.2 mm (1.7 in)
1968
56.4 mm (2.2 in)
1969
43.4 mm (1.7 in)
1970
47.5 mm (1.9 in)
1971
47.5 mm (1.9 in)
1972
42.4 mm (1.7 in)
1973
49.0 mm (1.9 in)
1974
40.9 mm (1.6 in)
1975
29.7 mm (1.2 in)
1976
23.1 mm (0.9 in)
1977
32.8 mm (1.3 in)
1978
29.4 mm (1.2 in)
1979
29.0 mm (1.1 in)
1980
44.8 mm (1.8 in)
1981
26.8 mm (1.1 in)
1982
35.4 mm (1.4 in)
1983
38.8 mm (1.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Sioux Lookout A, 1938 to 1983. The record is 184.1 mm (7.2 in) in 1941, marked on the chart; the median year is 64.8 mm (2.6 in).
Wettest five days (Rx5day) at Sioux Lookout A by year
Year
Wettest five days (Rx5day)
1938
42.4 mm (1.7 in)
1939
82.1 mm (3.2 in)
1940
62.0 mm (2.4 in)
1941
184.1 mm (7.2 in)
1942
55.7 mm (2.2 in)
1943
145.5 mm (5.7 in)
1944
64.0 mm (2.5 in)
1945
65.6 mm (2.6 in)
1946
69.4 mm (2.7 in)
1947
54.1 mm (2.1 in)
1948
41.1 mm (1.6 in)
1949
63.2 mm (2.5 in)
1950
93.4 mm (3.7 in)
1951
79.2 mm (3.1 in)
1952
67.8 mm (2.7 in)
1953
60.7 mm (2.4 in)
1954
80.9 mm (3.2 in)
1955
47.3 mm (1.9 in)
1956
48.0 mm (1.9 in)
1957
59.0 mm (2.3 in)
1958
53.3 mm (2.1 in)
1959
85.6 mm (3.4 in)
1960
30.7 mm (1.2 in)
1961
95.3 mm (3.8 in)
1962
81.8 mm (3.2 in)
1963
85.7 mm (3.4 in)
1964
97.3 mm (3.8 in)
1965
50.1 mm (2.0 in)
1966
144.8 mm (5.7 in)
1967
58.9 mm (2.3 in)
1968
70.2 mm (2.8 in)
1969
87.5 mm (3.4 in)
1970
77.8 mm (3.1 in)
1971
68.1 mm (2.7 in)
1972
55.1 mm (2.2 in)
1973
68.6 mm (2.7 in)
1974
94.8 mm (3.7 in)
1975
42.6 mm (1.7 in)
1976
43.5 mm (1.7 in)
1977
54.8 mm (2.2 in)
1978
56.8 mm (2.2 in)
1979
43.1 mm (1.7 in)
1980
51.8 mm (2.0 in)
1981
58.4 mm (2.3 in)
1982
79.4 mm (3.1 in)
1983
73.9 mm (2.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at Sioux Lookout A, 1938 to 1983. The record is 32 days in 1972, marked on the chart; the median year is 17 days.
Longest dry spell (CDD) at Sioux Lookout A by year
Year
Longest dry spell (CDD)
1938
11 days
1939
31 days
1940
19 days
1941
14 days
1942
16 days
1943
19 days
1944
28 days
1945
13 days
1946
15 days
1947
15 days
1948
26 days
1949
11 days
1950
16 days
1951
11 days
1952
26 days
1953
16 days
1954
17 days
1955
20 days
1956
23 days
1957
15 days
1958
30 days
1959
12 days
1960
25 days
1961
19 days
1962
19 days
1963
18 days
1964
15 days
1965
11 days
1966
14 days
1967
24 days
1968
11 days
1969
28 days
1970
16 days
1971
14 days
1972
32 days
1973
20 days
1974
15 days
1975
18 days
1976
15 days
1977
15 days
1978
25 days
1979
13 days
1980
23 days
1981
20 days
1982
19 days
1983
17 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
44 years with a frost
Across 44 years with a frost, the median last spring frost at Sioux Lookout A falls on 28 May and the median first autumn frost on 20 September, which leaves a median of 113 days between them.
Fitted over all years, the growing season changes by +0.8 days per decade at this station.
Frost dates and growing season at Sioux Lookout A
Measure
Median, all years
Earliest period
Recent period (1953 to 1983)
Recent against earliest
Fitted trend
Last spring frost
28 May
n/a
26 May
n/a
-0.4 days per decade
First autumn frost
20 September
n/a
20 September
n/a
+0.4 days per decade
Growing days
113 days
n/a
117 days
n/a
+0.8 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
45 years, 1939 to 1983
A day with at least 38.6 mm (1.5 in) of rain is expected about once in 2 years. A day with at least 98.1 mm (3.9 in) of rain is expected about once in 100 years.
Rainfall return levels at Sioux Lookout A: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
38.6 mm (1.5 in)
5 years
51.6 mm (2.0 in)
10 years
61.3 mm (2.4 in)
25 years
74.9 mm (2.9 in)
50 years
86.1 mm (3.4 in)
Longer than the 45 years of record
100 years
98.1 mm (3.9 in)
Longer than the 45 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, 45 years of values from 1939 to 1983.
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: 115.8 mm (4.6 in) in 1941; 75.9 mm (3.0 in) in 1943; 69.9 mm (2.8 in) in 1961.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Sioux Lookout A standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Sioux Lookout A 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.