Record envelope, standing records and threshold days for Alliston (CA008300100), Prince Edward Island, Canada, with 81 years of record.
Key Facts for Alliston
Alliston (CA008300100) is a weather station in Prince Edward Island, Canada at 46.07 latitude and -62.60 longitude, 61 m (200 ft) above sea level.
The station reports from 1936 to 2016, 81 years of record.
1,464 records set at Alliston still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Alliston set a daily record low minimum temperature of -16.0 C (3.2 F) on 29 March 1982.
About the Station
Location: Prince Edward Island, Canada, 46.07 latitude, -62.60 longitude.
Elevation: 61 m (200 ft).
Period of record: 1936 to 2016, 81 years.
Eligible elements: tmax, tmin, prcp, snow.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Alliston. 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 Alliston, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
12.8 C (55.0 F)
-26.1 C (-15.0 F)
n/a
n/a
Feb
13.5 C (56.3 F)
-26.7 C (-16.1 F)
n/a
n/a
Mar
18.3 C (64.9 F)
-27.8 C (-18.0 F)
n/a
n/a
Apr
26.1 C (79.0 F)
-13.0 C (8.6 F)
n/a
n/a
May
30.6 C (87.1 F)
-6.7 C (19.9 F)
n/a
n/a
Jun
32.8 C (91.0 F)
-3.9 C (25.0 F)
n/a
n/a
Jul
33.9 C (93.0 F)
2.0 C (35.6 F)
n/a
n/a
Aug
36.1 C (97.0 F)
4.4 C (39.9 F)
n/a
n/a
Sep
32.2 C (90.0 F)
-0.6 C (30.9 F)
n/a
n/a
Oct
25.0 C (77.0 F)
-6.1 C (21.0 F)
n/a
n/a
Nov
21.1 C (70.0 F)
-13.3 C (8.1 F)
n/a
n/a
Dec
17.8 C (64.0 F)
-23.9 C (-11.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Alliston still stand. 1936 holds the most, with 61.
Standing records at Alliston by the year they were set
Year set
Standing records
1936
61
1937
54
1938
44
1939
46
1940
30
1941
41
1942
46
1943
28
1944
44
1945
35
1946
33
1947
41
1948
30
1949
39
1950
38
1951
33
1952
14
1953
28
1954
25
1955
21
1956
28
1957
33
1958
19
1959
28
1960
16
1961
32
1962
19
1963
34
1964
21
1965
32
1966
24
1967
41
1968
24
1969
25
1970
15
1971
21
1972
41
1973
25
1974
25
1975
30
1976
34
1977
24
1978
22
1979
58
1980
18
1981
40
1982
4
All-Time Record Progression
2 new records
2 all-time records were set at Alliston between 15 August 1971 and 19 July 1979. Each dot is a new record.
When Alliston set new all-time records
Date
Kind
Detail
1971-08-15
Record daily precipitation
Record daily precipitation 127.5 mm (5.0 in)
1979-07-19
Record high minimum temperature
Record high minimum temperature 22.5 C (72.5 F)
Wettest Day of Each Month
Aug: 127.5 mm (5.0 in)
The wettest day on record for each calendar month at Alliston. The most was 127.5 mm (5.0 in) on 15 August 1971.
Record daily precipitation for each month at Alliston
Month
Record daily precipitation (mm)
Date
Jan
38.1 mm (1.5 in)
25 January 1978
Feb
63.5 mm (2.5 in)
26 February 1979
Mar
30.5 mm (1.2 in)
8 March 1960
Apr
40.6 mm (1.6 in)
16 April 1964
May
54.4 mm (2.1 in)
1 May 1947
Jun
57.2 mm (2.3 in)
17 June 1973
Jul
63.5 mm (2.5 in)
21 July 1942
Aug
127.5 mm (5.0 in)
15 August 1971
Sep
78.5 mm (3.1 in)
28 September 1958
Oct
63.0 mm (2.5 in)
15 October 1978
Nov
52.1 mm (2.1 in)
8 November 1968
Dec
52.1 mm (2.1 in)
31 December 1978
Period of Record Coverage
1936 to 1982
Complete yearUnder 90 percent of days
47 years of record at Alliston, 1936 to 1982. 3 years have data for under 90 percent of days and are left out of rankings: 1943, 1981, 1982.
Cooler than the station meanWarmer than the station mean
One stripe for each of 40 complete years at Alliston, 1936 to 1980. Blue stripes are years cooler than the station's own mean of 5.9 C (42.6 F); red stripes are warmer. The coolest year was 1965, at 4.8 C (40.6 F), and the warmest was 1951, at 7.4 C (45.2 F). The strongest colour marks a difference of 1.5 C (2.7 F).
Annual mean temperature at Alliston as warming stripes, 1936 to 1980
Year
Annual mean temperature
Difference from the station mean
1936
6.9 C
+0.94 C
1937
7.0 C
+1.06 C
1938
6.3 C
+0.39 C
1939
5.5 C
-0.38 C
1940
5.6 C
-0.33 C
1941
5.4 C
-0.50 C
1944
6.3 C
+0.42 C
1945
6.7 C
+0.82 C
1946
6.4 C
+0.51 C
1947
6.7 C
+0.77 C
1948
5.6 C
-0.28 C
1949
7.0 C
+1.06 C
1950
6.0 C
+0.07 C
1951
7.4 C
+1.44 C
1952
6.8 C
+0.87 C
1954
6.7 C
+0.82 C
1955
6.1 C
+0.18 C
1956
5.2 C
-0.70 C
1958
5.6 C
-0.31 C
1959
5.5 C
-0.37 C
1960
6.1 C
+0.14 C
1961
5.4 C
-0.56 C
1962
4.9 C
-0.99 C
1963
5.2 C
-0.71 C
1964
4.9 C
-0.98 C
1965
4.8 C
-1.13 C
1966
6.4 C
+0.48 C
1967
5.3 C
-0.60 C
1968
5.7 C
-0.23 C
1969
6.6 C
+0.71 C
1970
5.6 C
-0.34 C
1971
6.0 C
+0.08 C
1972
4.8 C
-1.07 C
1973
6.3 C
+0.34 C
1974
5.3 C
-0.65 C
1975
5.8 C
-0.11 C
1976
6.1 C
+0.17 C
1977
6.1 C
+0.22 C
1978
5.3 C
-0.61 C
1980
5.1 C
-0.82 C
The annual mean temperature here has fallen by 0.2 C (0.1 to 0.4) per decade over 1936 to 1980. In Fahrenheit: 0.4 F (0.1 to 0.7) per decade. The slope is a straight line fitted to 40 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Alliston
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.2 C (-0.4 to -0.1) per decade
-0.4 F (-0.7 to -0.1) per decade
1936 to 1980
40
Fall
Mean daily maximum
-0.2 C (-0.4 to -0.1) per decade
-0.4 F (-0.6 to -0.1) per decade
1936 to 1980
40
Fall
Mean daily minimum
-0.3 C (-0.4 to -0.1) per decade
-0.5 F (-0.8 to -0.1) per decade
1936 to 1980
40
Fall
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
1936 to 1982
Yearly extremes at Alliston: 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)
1944
31.1 C (88.0 F)
47
Coldest night (TNn)
-27.8 C (-18.0 F)
1938
-23.9 C (-11.0 F)
47
Wettest day (Rx1day)
127.5 mm (5.0 in)
1971
45.5 mm (1.8 in)
47
Wettest five days (Rx5day)
198.9 mm (7.8 in)
1971
71.6 mm (2.8 in)
47
Longest dry spell (CDD)
28 days
1939
14 days
47
Hottest day (TXx)
The hottest day of the year at Alliston, 1936 to 1982. The record is 36.1 C (97.0 F) in 1944, marked on the chart; the median year is 31.1 C (88.0 F).
Hottest day (TXx) at Alliston by year
Year
Hottest day (TXx)
1936
30.6 C (87.1 F)
1937
34.4 C (93.9 F)
1938
32.8 C (91.0 F)
1939
32.8 C (91.0 F)
1940
32.2 C (90.0 F)
1941
31.1 C (88.0 F)
1942
32.8 C (91.0 F)
1943
26.7 C (80.1 F)
1944
36.1 C (97.0 F)
1945
31.1 C (88.0 F)
1946
30.6 C (87.1 F)
1947
31.7 C (89.1 F)
1948
32.2 C (90.0 F)
1949
33.9 C (93.0 F)
1950
31.1 C (88.0 F)
1951
29.4 C (84.9 F)
1952
33.3 C (91.9 F)
1953
30.6 C (87.1 F)
1954
28.3 C (82.9 F)
1955
32.2 C (90.0 F)
1956
29.4 C (84.9 F)
1957
31.1 C (88.0 F)
1958
28.3 C (82.9 F)
1959
30.0 C (86.0 F)
1960
33.9 C (93.0 F)
1961
31.1 C (88.0 F)
1962
31.1 C (88.0 F)
1963
32.2 C (90.0 F)
1964
29.4 C (84.9 F)
1965
32.2 C (90.0 F)
1966
28.9 C (84.0 F)
1967
31.1 C (88.0 F)
1968
30.6 C (87.1 F)
1969
30.0 C (86.0 F)
1970
30.6 C (87.1 F)
1971
30.6 C (87.1 F)
1972
31.1 C (88.0 F)
1973
30.0 C (86.0 F)
1974
30.6 C (87.1 F)
1975
33.9 C (93.0 F)
1976
32.8 C (91.0 F)
1977
31.1 C (88.0 F)
1978
30.0 C (86.0 F)
1979
32.0 C (89.6 F)
1980
31.0 C (87.8 F)
1981
30.0 C (86.0 F)
1982
10.0 C (50.0 F)
Coldest night (TNn)
The coldest night of the year at Alliston, 1936 to 1982. The record is -27.8 C (-18.0 F) in 1938, marked on the chart; the median year is -23.9 C (-11.0 F).
Coldest night (TNn) at Alliston by year
Year
Coldest night (TNn)
1936
-22.8 C (-9.0 F)
1937
-23.9 C (-11.0 F)
1938
-27.8 C (-18.0 F)
1939
-24.4 C (-11.9 F)
1940
-23.3 C (-9.9 F)
1941
-21.7 C (-7.1 F)
1942
-23.9 C (-11.0 F)
1943
-26.1 C (-15.0 F)
1944
-22.2 C (-8.0 F)
1945
-20.6 C (-5.1 F)
1946
-25.0 C (-13.0 F)
1947
-21.1 C (-6.0 F)
1948
-26.7 C (-16.1 F)
1949
-18.9 C (-2.0 F)
1950
-25.6 C (-14.1 F)
1951
-25.6 C (-14.1 F)
1952
-20.6 C (-5.1 F)
1953
-17.8 C (0.0 F)
1954
-22.8 C (-9.0 F)
1955
-26.7 C (-16.1 F)
1956
-18.9 C (-2.0 F)
1957
-26.1 C (-15.0 F)
1958
-21.1 C (-6.0 F)
1959
-22.8 C (-9.0 F)
1960
-24.4 C (-11.9 F)
1961
-25.6 C (-14.1 F)
1962
-23.9 C (-11.0 F)
1963
-22.2 C (-8.0 F)
1964
-20.6 C (-5.1 F)
1965
-23.9 C (-11.0 F)
1966
-23.3 C (-9.9 F)
1967
-26.7 C (-16.1 F)
1968
-24.4 C (-11.9 F)
1969
-18.3 C (-0.9 F)
1970
-22.2 C (-8.0 F)
1971
-25.0 C (-13.0 F)
1972
-25.6 C (-14.1 F)
1973
-24.4 C (-11.9 F)
1974
-24.4 C (-11.9 F)
1975
-26.1 C (-15.0 F)
1976
-21.7 C (-7.1 F)
1977
-20.6 C (-5.1 F)
1978
-23.0 C (-9.4 F)
1979
-23.3 C (-9.9 F)
1980
-23.0 C (-9.4 F)
1981
-25.0 C (-13.0 F)
1982
-25.0 C (-13.0 F)
Wettest day (Rx1day)
The wettest day of the year at Alliston, 1936 to 1982. The record is 127.5 mm (5.0 in) in 1971, marked on the chart; the median year is 45.5 mm (1.8 in).
Wettest day (Rx1day) at Alliston by year
Year
Wettest day (Rx1day)
1936
45.5 mm (1.8 in)
1937
39.4 mm (1.6 in)
1938
56.6 mm (2.2 in)
1939
28.2 mm (1.1 in)
1940
51.8 mm (2.0 in)
1941
29.7 mm (1.2 in)
1942
63.5 mm (2.5 in)
1943
33.8 mm (1.3 in)
1944
36.6 mm (1.4 in)
1945
30.5 mm (1.2 in)
1946
27.7 mm (1.1 in)
1947
54.4 mm (2.1 in)
1948
31.5 mm (1.2 in)
1949
81.8 mm (3.2 in)
1950
19.6 mm (0.8 in)
1951
44.5 mm (1.8 in)
1952
26.9 mm (1.1 in)
1953
24.1 mm (0.9 in)
1954
42.2 mm (1.7 in)
1955
51.1 mm (2.0 in)
1956
35.1 mm (1.4 in)
1957
39.1 mm (1.5 in)
1958
78.5 mm (3.1 in)
1959
50.3 mm (2.0 in)
1960
42.2 mm (1.7 in)
1961
50.8 mm (2.0 in)
1962
45.5 mm (1.8 in)
1963
46.5 mm (1.8 in)
1964
42.9 mm (1.7 in)
1965
28.2 mm (1.1 in)
1966
48.3 mm (1.9 in)
1967
48.0 mm (1.9 in)
1968
63.5 mm (2.5 in)
1969
55.9 mm (2.2 in)
1970
42.7 mm (1.7 in)
1971
127.5 mm (5.0 in)
1972
36.6 mm (1.4 in)
1973
57.2 mm (2.3 in)
1974
49.0 mm (1.9 in)
1975
38.9 mm (1.5 in)
1976
49.0 mm (1.9 in)
1977
68.8 mm (2.7 in)
1978
63.0 mm (2.5 in)
1979
63.5 mm (2.5 in)
1980
51.4 mm (2.0 in)
1981
46.0 mm (1.8 in)
1982
31.0 mm (1.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Alliston, 1936 to 1982. The record is 198.9 mm (7.8 in) in 1971, marked on the chart; the median year is 71.6 mm (2.8 in).
Wettest five days (Rx5day) at Alliston by year
Year
Wettest five days (Rx5day)
1936
77.2 mm (3.0 in)
1937
78.5 mm (3.1 in)
1938
70.4 mm (2.8 in)
1939
39.1 mm (1.5 in)
1940
79.2 mm (3.1 in)
1941
56.7 mm (2.2 in)
1942
149.4 mm (5.9 in)
1943
50.5 mm (2.0 in)
1944
57.9 mm (2.3 in)
1945
56.6 mm (2.2 in)
1946
45.7 mm (1.8 in)
1947
67.8 mm (2.7 in)
1948
35.4 mm (1.4 in)
1949
87.7 mm (3.5 in)
1950
33.0 mm (1.3 in)
1951
56.7 mm (2.2 in)
1952
37.8 mm (1.5 in)
1953
37.3 mm (1.5 in)
1954
51.3 mm (2.0 in)
1955
97.6 mm (3.8 in)
1956
99.6 mm (3.9 in)
1957
109.7 mm (4.3 in)
1958
89.9 mm (3.5 in)
1959
73.3 mm (2.9 in)
1960
50.6 mm (2.0 in)
1961
67.4 mm (2.7 in)
1962
74.7 mm (2.9 in)
1963
76.4 mm (3.0 in)
1964
62.2 mm (2.4 in)
1965
53.6 mm (2.1 in)
1966
72.4 mm (2.9 in)
1967
78.8 mm (3.1 in)
1968
118.2 mm (4.7 in)
1969
91.2 mm (3.6 in)
1970
73.4 mm (2.9 in)
1971
198.9 mm (7.8 in)
1972
60.0 mm (2.4 in)
1973
71.6 mm (2.8 in)
1974
74.2 mm (2.9 in)
1975
58.7 mm (2.3 in)
1976
84.3 mm (3.3 in)
1977
80.5 mm (3.2 in)
1978
65.0 mm (2.6 in)
1979
89.0 mm (3.5 in)
1980
68.7 mm (2.7 in)
1981
79.0 mm (3.1 in)
1982
56.0 mm (2.2 in)
Longest dry spell (CDD)
The longest dry spell of the year at Alliston, 1936 to 1982. The record is 28 days in 1939, marked on the chart; the median year is 14 days.
Longest dry spell (CDD) at Alliston by year
Year
Longest dry spell (CDD)
1936
10 days
1937
18 days
1938
18 days
1939
28 days
1940
22 days
1941
10 days
1942
18 days
1943
16 days
1944
17 days
1945
13 days
1946
11 days
1947
20 days
1948
15 days
1949
17 days
1950
25 days
1951
14 days
1952
15 days
1953
14 days
1954
20 days
1955
11 days
1956
15 days
1957
11 days
1958
18 days
1959
10 days
1960
17 days
1961
19 days
1962
13 days
1963
10 days
1964
10 days
1965
17 days
1966
13 days
1967
13 days
1968
12 days
1969
19 days
1970
12 days
1971
12 days
1972
13 days
1973
14 days
1974
13 days
1975
19 days
1976
11 days
1977
9 days
1978
18 days
1979
14 days
1980
11 days
1981
14 days
1982
12 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
40 years with a frost
Across 40 years with a frost, the median last spring frost at Alliston falls on 21 May and the median first autumn frost on 14 October, which leaves a median of 148 days between them.
Fitted over all years, the growing season changes by 0.0 days per decade at this station.
Frost dates and growing season at Alliston
Measure
Median, all years
Earliest period
Recent period (1948 to 1980)
Recent against earliest
Fitted trend
Last spring frost
21 May
n/a
19 May
n/a
-1.2 days per decade
First autumn frost
14 October
n/a
14 October
n/a
-1.2 days per decade
Growing days
148 days
n/a
150 days
n/a
0.0 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
43 years, 1936 to 1981
A day with at least 44.9 mm (1.8 in) of rain is expected about once in 2 years. A day with at least 107.0 mm (4.2 in) of rain is expected about once in 100 years.
Rainfall return levels at Alliston: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
44.9 mm (1.8 in)
5 years
60.4 mm (2.4 in)
10 years
71.0 mm (2.8 in)
25 years
85.0 mm (3.3 in)
50 years
95.9 mm (3.8 in)
Longer than the 43 years of record
100 years
107.0 mm (4.2 in)
Longer than the 43 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, 43 years of values from 1936 to 1981.
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: 127.5 mm (5.0 in) in 1971; 81.8 mm (3.2 in) in 1949; 78.5 mm (3.1 in) in 1958.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Alliston, at 1941. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1941 ran 0.5 C (0.8 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Alliston, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1941
-0.5
-0.8
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 Alliston standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Alliston 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.