Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Brockville. 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 Brockville, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
16.7 C (62.1 F)
-38.3 C (-36.9 F)
n/a
n/a
Feb
13.9 C (57.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Mar
26.1 C (79.0 F)
-31.7 C (-25.1 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-15.0 C (5.0 F)
n/a
n/a
May
32.2 C (90.0 F)
-6.1 C (21.0 F)
n/a
n/a
Jun
39.4 C (102.9 F)
0.0 C (32.0 F)
n/a
n/a
Jul
39.4 C (102.9 F)
2.8 C (37.0 F)
n/a
n/a
Aug
36.7 C (98.1 F)
1.7 C (35.1 F)
n/a
n/a
Sep
34.4 C (93.9 F)
-3.9 C (25.0 F)
n/a
n/a
Oct
27.8 C (82.0 F)
-11.1 C (12.0 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-26.1 C (-15.0 F)
n/a
n/a
Dec
17.2 C (63.0 F)
-36.1 C (-33.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Brockville still stand. 1921 holds the most, with 54.
Standing records at Brockville by the year they were set
Year set
Standing records
1872
11
1873
17
1874
27
1875
47
1876
22
1877
13
1878
22
1879
9
1885
10
1886
20
1890
9
1915
4
1916
27
1917
26
1918
24
1919
32
1920
21
1921
54
1922
18
1923
9
1924
7
1925
10
1926
8
1927
15
1928
17
1929
19
1930
24
1931
19
1932
20
1933
26
1934
24
1935
20
1936
18
1937
15
1938
14
1939
16
1940
26
1941
14
1942
19
1943
27
1944
26
1945
27
1946
30
1947
29
1948
19
1949
27
1950
12
1951
16
1952
8
1953
18
1954
19
1955
16
1956
7
1957
22
1958
6
1959
26
1960
7
1961
10
1962
6
1963
16
1964
28
1965
26
1966
18
1967
12
1968
21
1969
13
1970
13
1971
17
1972
17
1973
16
1974
15
1975
20
1976
37
1977
20
1978
17
1979
39
1980
8
All-Time Record Progression
5 new records
5 all-time records were set at Brockville between 7 February 1942 and 14 September 1979. Each dot is a new record.
When Brockville set new all-time records
Date
Kind
Detail
1942-02-07
Record daily snowfall
Record daily snowfall 43.2 cm (17.0 in)
1951-07-04
Record daily precipitation
Record daily precipitation 89.4 mm (3.5 in)
1954-02-16
Record daily snowfall
Record daily snowfall 47.5 cm (18.7 in)
1966-01-30
Record daily snowfall
Record daily snowfall 51.8 cm (20.4 in)
1979-09-14
Record daily precipitation
Record daily precipitation 100.8 mm (4.0 in)
Wettest Day of Each Month
Sep: 100.8 mm (4.0 in)
The wettest day on record for each calendar month at Brockville. The most was 100.8 mm (4.0 in) on 14 September 1979.
Record daily precipitation for each month at Brockville
Month
Record daily precipitation (mm)
Date
Jan
51.8 mm (2.0 in)
30 January 1966
Feb
47.5 mm (1.9 in)
16 February 1954
Mar
45.7 mm (1.8 in)
14 March 1895
Apr
45.2 mm (1.8 in)
30 April 1925
May
64.8 mm (2.6 in)
11 May 1943
Jun
67.3 mm (2.6 in)
27 June 1919
Jul
89.4 mm (3.5 in)
4 July 1951
Aug
64.8 mm (2.6 in)
22 August 1915
Sep
100.8 mm (4.0 in)
14 September 1979
Oct
87.1 mm (3.4 in)
23 October 1923
Nov
54.6 mm (2.1 in)
30 November 1923
Dec
35.1 mm (1.4 in)
19 December 1934
Period of Record Coverage
1872 to 1980
Complete yearUnder 90 percent of days
77 years of record at Brockville, 1872 to 1980. 8 years have data for under 90 percent of days and are left out of rankings: 1872, 1879, 1885, 1890, 1915, 1938, 1962, 1980.
Cooler than the station meanWarmer than the station mean
One stripe for each of 67 complete years at Brockville, 1873 to 1979. Blue stripes are years cooler than the station's own mean of 7.0 C (44.5 F); red stripes are warmer. The coolest year was 1875, at 4.0 C (39.2 F), and the warmest was 1953, at 9.2 C (48.6 F). The strongest colour marks a difference of 3.0 C (5.4 F).
Annual mean temperature at Brockville as warming stripes, 1873 to 1979
Year
Annual mean temperature
Difference from the station mean
1873
5.5 C
-1.47 C
1874
5.7 C
-1.26 C
1875
4.0 C
-2.95 C
1876
5.9 C
-1.07 C
1877
7.4 C
+0.47 C
1878
7.9 C
+0.95 C
1886
6.3 C
-0.64 C
1916
7.2 C
+0.21 C
1917
5.4 C
-1.57 C
1918
6.8 C
-0.20 C
1919
7.9 C
+0.93 C
1920
7.0 C
-0.01 C
1921
9.0 C
+1.98 C
1922
7.7 C
+0.70 C
1924
6.3 C
-0.70 C
1926
6.0 C
-0.98 C
1927
7.7 C
+0.71 C
1928
7.2 C
+0.19 C
1929
6.5 C
-0.45 C
1930
7.5 C
+0.49 C
1931
8.4 C
+1.47 C
1932
7.7 C
+0.68 C
1933
7.2 C
+0.21 C
1934
6.3 C
-0.71 C
1935
6.4 C
-0.55 C
1936
6.4 C
-0.62 C
1937
7.7 C
+0.74 C
1939
6.4 C
-0.54 C
1940
5.9 C
-1.07 C
1941
7.2 C
+0.27 C
1942
7.1 C
+0.14 C
1943
5.8 C
-1.21 C
1944
6.8 C
-0.20 C
1945
6.7 C
-0.30 C
1946
7.5 C
+0.49 C
1947
7.0 C
+0.00 C
1948
7.5 C
+0.53 C
1949
8.4 C
+1.45 C
1950
7.0 C
+0.06 C
1951
7.5 C
+0.55 C
1952
8.5 C
+1.51 C
1953
9.2 C
+2.26 C
1954
7.5 C
+0.57 C
1955
8.0 C
+1.04 C
1956
7.0 C
+0.03 C
1957
8.3 C
+1.31 C
1958
7.0 C
+0.04 C
1959
7.8 C
+0.80 C
1960
7.8 C
+0.81 C
1961
7.7 C
+0.70 C
1963
5.9 C
-1.05 C
1964
7.3 C
+0.34 C
1965
6.3 C
-0.65 C
1966
6.7 C
-0.31 C
1967
6.5 C
-0.52 C
1968
6.3 C
-0.69 C
1969
6.7 C
-0.26 C
1970
6.2 C
-0.73 C
1971
6.6 C
-0.39 C
1972
5.8 C
-1.17 C
1973
7.8 C
+0.86 C
1974
6.5 C
-0.43 C
1975
7.5 C
+0.56 C
1976
6.1 C
-0.83 C
1977
7.2 C
+0.19 C
1978
5.8 C
-1.16 C
1979
7.1 C
+0.14 C
The fitted trend in annual mean temperature here over 1873 to 1979 is 0.06 C (-0.01 to 0.14) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.12 F (-0.03 to 0.26) per decade. The slope is a straight line fitted to 67 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Brockville
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.06 C (-0.01 to 0.14) per decade
0.12 F (-0.03 to 0.26) per decade
1873 to 1979
67
Not clearly different from zero
Mean daily maximum
0.02 C (-0.07 to 0.10) per decade
0.03 F (-0.12 to 0.18) per decade
1873 to 1979
67
Not clearly different from zero
Mean daily minimum
0.11 C (0.03 to 0.20) per decade
0.2 F (0.1 to 0.4) per decade
1873 to 1979
67
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
1871 to 1980
Yearly extremes at Brockville: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
39.4 C (102.9 F)
1917
32.8 C (91.0 F)
77
Coldest night (TNn)
-38.3 C (-36.9 F)
1886
-30.6 C (-23.1 F)
77
Wettest day (Rx1day)
100.8 mm (4.0 in)
1979
44.7 mm (1.8 in)
79
Wettest five days (Rx5day)
143.6 mm (5.7 in)
1979
65.0 mm (2.6 in)
79
Longest dry spell (CDD)
42 days
1885
16 days
79
Hottest day (TXx)
The hottest day of the year at Brockville, 1871 to 1980. The record is 39.4 C (102.9 F) in 1917, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Brockville by year
Year
Hottest day (TXx)
1871
n/a
1872
31.1 C (88.0 F)
1873
31.1 C (88.0 F)
1874
31.7 C (89.1 F)
1875
31.7 C (89.1 F)
1876
33.9 C (93.0 F)
1877
33.3 C (91.9 F)
1878
34.4 C (93.9 F)
1879
32.8 C (91.0 F)
1885
28.9 C (84.0 F)
1886
32.2 C (90.0 F)
1890
26.1 C (79.0 F)
1895
n/a
1915
29.4 C (84.9 F)
1916
37.2 C (99.0 F)
1917
39.4 C (102.9 F)
1918
35.0 C (95.0 F)
1919
39.4 C (102.9 F)
1920
33.9 C (93.0 F)
1921
38.3 C (100.9 F)
1922
33.3 C (91.9 F)
1923
34.4 C (93.9 F)
1924
32.8 C (91.0 F)
1925
32.8 C (91.0 F)
1926
34.4 C (93.9 F)
1927
32.8 C (91.0 F)
1928
32.8 C (91.0 F)
1929
32.2 C (90.0 F)
1930
31.7 C (89.1 F)
1931
38.3 C (100.9 F)
1932
31.1 C (88.0 F)
1933
35.6 C (96.1 F)
1934
33.9 C (93.0 F)
1935
32.2 C (90.0 F)
1936
34.4 C (93.9 F)
1937
31.7 C (89.1 F)
1938
33.9 C (93.0 F)
1939
33.9 C (93.0 F)
1940
32.8 C (91.0 F)
1941
35.6 C (96.1 F)
1942
34.4 C (93.9 F)
1943
32.8 C (91.0 F)
1944
36.7 C (98.1 F)
1945
33.3 C (91.9 F)
1946
33.9 C (93.0 F)
1947
33.3 C (91.9 F)
1948
34.4 C (93.9 F)
1949
36.1 C (97.0 F)
1950
32.2 C (90.0 F)
1951
31.7 C (89.1 F)
1952
33.3 C (91.9 F)
1953
34.4 C (93.9 F)
1954
31.1 C (88.0 F)
1955
35.0 C (95.0 F)
1956
30.6 C (87.1 F)
1957
32.8 C (91.0 F)
1958
31.1 C (88.0 F)
1959
35.0 C (95.0 F)
1960
32.8 C (91.0 F)
1961
31.1 C (88.0 F)
1962
30.6 C (87.1 F)
1963
32.8 C (91.0 F)
1964
35.0 C (95.0 F)
1965
31.7 C (89.1 F)
1966
33.3 C (91.9 F)
1967
30.6 C (87.1 F)
1968
32.2 C (90.0 F)
1969
32.2 C (90.0 F)
1970
31.1 C (88.0 F)
1971
30.6 C (87.1 F)
1972
31.1 C (88.0 F)
1973
32.8 C (91.0 F)
1974
30.6 C (87.1 F)
1975
34.4 C (93.9 F)
1976
30.0 C (86.0 F)
1977
33.0 C (91.4 F)
1978
33.0 C (91.4 F)
1979
33.0 C (91.4 F)
1980
32.0 C (89.6 F)
Coldest night (TNn)
The coldest night of the year at Brockville, 1871 to 1980. The record is -38.3 C (-36.9 F) in 1886, marked on the chart; the median year is -30.6 C (-23.1 F).
Coldest night (TNn) at Brockville by year
Year
Coldest night (TNn)
1871
n/a
1872
-35.6 C (-32.1 F)
1873
-31.7 C (-25.1 F)
1874
-31.7 C (-25.1 F)
1875
-36.1 C (-33.0 F)
1876
-30.0 C (-22.0 F)
1877
-30.0 C (-22.0 F)
1878
-32.2 C (-26.0 F)
1879
-32.8 C (-27.0 F)
1885
-18.3 C (-0.9 F)
1886
-38.3 C (-36.9 F)
1890
-23.9 C (-11.0 F)
1895
n/a
1915
-19.4 C (-2.9 F)
1916
-30.6 C (-23.1 F)
1917
-33.9 C (-29.0 F)
1918
-32.8 C (-27.0 F)
1919
-26.1 C (-15.0 F)
1920
-33.3 C (-27.9 F)
1921
-28.9 C (-20.0 F)
1922
-27.8 C (-18.0 F)
1923
-18.9 C (-2.0 F)
1924
-36.7 C (-34.1 F)
1925
-38.3 C (-36.9 F)
1926
-28.9 C (-20.0 F)
1927
-27.2 C (-17.0 F)
1928
-27.2 C (-17.0 F)
1929
-27.2 C (-17.0 F)
1930
-31.1 C (-24.0 F)
1931
-27.2 C (-17.0 F)
1932
-30.0 C (-22.0 F)
1933
-36.1 C (-33.0 F)
1934
-32.8 C (-27.0 F)
1935
-33.9 C (-29.0 F)
1936
-28.3 C (-18.9 F)
1937
-26.1 C (-15.0 F)
1938
-31.7 C (-25.1 F)
1939
-32.2 C (-26.0 F)
1940
-29.4 C (-20.9 F)
1941
-27.2 C (-17.0 F)
1942
-35.0 C (-31.0 F)
1943
-35.6 C (-32.1 F)
1944
-31.1 C (-24.0 F)
1945
-32.8 C (-27.0 F)
1946
-32.2 C (-26.0 F)
1947
-26.1 C (-15.0 F)
1948
-32.8 C (-27.0 F)
1949
-26.7 C (-16.1 F)
1950
-31.1 C (-24.0 F)
1951
-30.6 C (-23.1 F)
1952
-26.7 C (-16.1 F)
1953
-23.3 C (-9.9 F)
1954
-31.7 C (-25.1 F)
1955
-28.9 C (-20.0 F)
1956
-24.4 C (-11.9 F)
1957
-34.4 C (-29.9 F)
1958
-26.7 C (-16.1 F)
1959
-27.2 C (-17.0 F)
1960
-26.7 C (-16.1 F)
1961
-27.2 C (-17.0 F)
1962
-27.8 C (-18.0 F)
1963
-31.1 C (-24.0 F)
1964
-27.8 C (-18.0 F)
1965
-31.1 C (-24.0 F)
1966
-32.2 C (-26.0 F)
1967
-32.2 C (-26.0 F)
1968
-35.0 C (-31.0 F)
1969
-23.9 C (-11.0 F)
1970
-31.7 C (-25.1 F)
1971
-31.7 C (-25.1 F)
1972
-33.3 C (-27.9 F)
1973
-28.3 C (-18.9 F)
1974
-26.7 C (-16.1 F)
1975
-28.9 C (-20.0 F)
1976
-31.7 C (-25.1 F)
1977
-27.8 C (-18.0 F)
1978
-30.0 C (-22.0 F)
1979
-33.5 C (-28.3 F)
1980
-24.5 C (-12.1 F)
Wettest day (Rx1day)
The wettest day of the year at Brockville, 1871 to 1980. The record is 100.8 mm (4.0 in) in 1979, marked on the chart; the median year is 44.7 mm (1.8 in).
Wettest day (Rx1day) at Brockville by year
Year
Wettest day (Rx1day)
1871
20.3 mm (0.8 in)
1872
48.3 mm (1.9 in)
1873
53.8 mm (2.1 in)
1874
31.8 mm (1.3 in)
1875
38.1 mm (1.5 in)
1876
35.6 mm (1.4 in)
1877
38.1 mm (1.5 in)
1878
53.3 mm (2.1 in)
1879
27.7 mm (1.1 in)
1885
46.2 mm (1.8 in)
1886
49.5 mm (1.9 in)
1890
35.1 mm (1.4 in)
1895
45.7 mm (1.8 in)
1915
64.8 mm (2.6 in)
1916
38.6 mm (1.5 in)
1917
36.8 mm (1.4 in)
1918
81.8 mm (3.2 in)
1919
67.3 mm (2.6 in)
1920
22.9 mm (0.9 in)
1921
30.2 mm (1.2 in)
1922
40.4 mm (1.6 in)
1923
87.1 mm (3.4 in)
1924
77.5 mm (3.1 in)
1925
45.2 mm (1.8 in)
1926
47.5 mm (1.9 in)
1927
43.9 mm (1.7 in)
1928
53.8 mm (2.1 in)
1929
48.3 mm (1.9 in)
1930
25.1 mm (1.0 in)
1931
26.7 mm (1.1 in)
1932
27.9 mm (1.1 in)
1933
49.5 mm (1.9 in)
1934
40.6 mm (1.6 in)
1935
42.2 mm (1.7 in)
1936
44.7 mm (1.8 in)
1937
49.0 mm (1.9 in)
1938
45.2 mm (1.8 in)
1939
58.2 mm (2.3 in)
1940
57.2 mm (2.3 in)
1941
39.4 mm (1.6 in)
1942
43.2 mm (1.7 in)
1943
64.8 mm (2.6 in)
1944
41.7 mm (1.6 in)
1945
54.6 mm (2.1 in)
1946
49.3 mm (1.9 in)
1947
45.2 mm (1.8 in)
1948
46.7 mm (1.8 in)
1949
34.8 mm (1.4 in)
1950
50.3 mm (2.0 in)
1951
89.4 mm (3.5 in)
1952
37.3 mm (1.5 in)
1953
59.2 mm (2.3 in)
1954
47.5 mm (1.9 in)
1955
72.4 mm (2.9 in)
1956
24.4 mm (1.0 in)
1957
35.1 mm (1.4 in)
1958
32.3 mm (1.3 in)
1959
53.1 mm (2.1 in)
1960
27.9 mm (1.1 in)
1961
44.7 mm (1.8 in)
1962
28.4 mm (1.1 in)
1963
40.4 mm (1.6 in)
1964
29.7 mm (1.2 in)
1965
33.0 mm (1.3 in)
1966
51.8 mm (2.0 in)
1967
50.3 mm (2.0 in)
1968
37.6 mm (1.5 in)
1969
52.1 mm (2.1 in)
1970
42.2 mm (1.7 in)
1971
34.0 mm (1.3 in)
1972
65.3 mm (2.6 in)
1973
36.6 mm (1.4 in)
1974
49.0 mm (1.9 in)
1975
63.2 mm (2.5 in)
1976
40.6 mm (1.6 in)
1977
45.0 mm (1.8 in)
1978
39.0 mm (1.5 in)
1979
100.8 mm (4.0 in)
1980
37.8 mm (1.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Brockville, 1871 to 1980. The record is 143.6 mm (5.7 in) in 1979, marked on the chart; the median year is 65.0 mm (2.6 in).
Wettest five days (Rx5day) at Brockville by year
Year
Wettest five days (Rx5day)
1871
38.1 mm (1.5 in)
1872
57.9 mm (2.3 in)
1873
76.1 mm (3.0 in)
1874
45.2 mm (1.8 in)
1875
49.3 mm (1.9 in)
1876
73.2 mm (2.9 in)
1877
56.6 mm (2.2 in)
1878
65.5 mm (2.6 in)
1879
50.0 mm (2.0 in)
1885
53.8 mm (2.1 in)
1886
74.9 mm (2.9 in)
1890
40.6 mm (1.6 in)
1895
48.2 mm (1.9 in)
1915
64.8 mm (2.6 in)
1916
83.1 mm (3.3 in)
1917
54.5 mm (2.1 in)
1918
86.9 mm (3.4 in)
1919
67.3 mm (2.6 in)
1920
52.0 mm (2.0 in)
1921
42.6 mm (1.7 in)
1922
52.6 mm (2.1 in)
1923
92.2 mm (3.6 in)
1924
83.3 mm (3.3 in)
1925
62.7 mm (2.5 in)
1926
80.0 mm (3.1 in)
1927
79.4 mm (3.1 in)
1928
67.3 mm (2.6 in)
1929
59.7 mm (2.4 in)
1930
55.1 mm (2.2 in)
1931
48.7 mm (1.9 in)
1932
53.8 mm (2.1 in)
1933
57.1 mm (2.2 in)
1934
45.5 mm (1.8 in)
1935
65.8 mm (2.6 in)
1936
53.8 mm (2.1 in)
1937
71.2 mm (2.8 in)
1938
76.5 mm (3.0 in)
1939
62.3 mm (2.5 in)
1940
75.3 mm (3.0 in)
1941
66.1 mm (2.6 in)
1942
65.1 mm (2.6 in)
1943
72.9 mm (2.9 in)
1944
67.0 mm (2.6 in)
1945
97.3 mm (3.8 in)
1946
72.4 mm (2.9 in)
1947
95.3 mm (3.8 in)
1948
64.5 mm (2.5 in)
1949
59.2 mm (2.3 in)
1950
83.8 mm (3.3 in)
1951
109.5 mm (4.3 in)
1952
92.7 mm (3.6 in)
1953
68.9 mm (2.7 in)
1954
93.2 mm (3.7 in)
1955
90.9 mm (3.6 in)
1956
54.7 mm (2.2 in)
1957
56.7 mm (2.2 in)
1958
58.5 mm (2.3 in)
1959
86.1 mm (3.4 in)
1960
58.7 mm (2.3 in)
1961
63.4 mm (2.5 in)
1962
50.0 mm (2.0 in)
1963
55.7 mm (2.2 in)
1964
49.0 mm (1.9 in)
1965
66.3 mm (2.6 in)
1966
76.7 mm (3.0 in)
1967
73.9 mm (2.9 in)
1968
61.2 mm (2.4 in)
1969
53.9 mm (2.1 in)
1970
85.6 mm (3.4 in)
1971
56.4 mm (2.2 in)
1972
66.4 mm (2.6 in)
1973
65.0 mm (2.6 in)
1974
55.6 mm (2.2 in)
1975
83.3 mm (3.3 in)
1976
80.9 mm (3.2 in)
1977
52.4 mm (2.1 in)
1978
58.6 mm (2.3 in)
1979
143.6 mm (5.7 in)
1980
67.0 mm (2.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Brockville, 1871 to 1980. The record is 42 days in 1885, marked on the chart; the median year is 16 days.
Longest dry spell (CDD) at Brockville by year
Year
Longest dry spell (CDD)
1871
16 days
1872
17 days
1873
15 days
1874
12 days
1875
14 days
1876
17 days
1877
20 days
1878
12 days
1879
15 days
1885
42 days
1886
19 days
1890
16 days
1895
10 days
1915
23 days
1916
22 days
1917
34 days
1918
18 days
1919
21 days
1920
22 days
1921
21 days
1922
29 days
1923
22 days
1924
35 days
1925
32 days
1926
16 days
1927
22 days
1928
18 days
1929
18 days
1930
21 days
1931
20 days
1932
22 days
1933
16 days
1934
16 days
1935
18 days
1936
14 days
1937
16 days
1938
13 days
1939
16 days
1940
13 days
1941
26 days
1942
16 days
1943
14 days
1944
19 days
1945
10 days
1946
10 days
1947
28 days
1948
14 days
1949
14 days
1950
11 days
1951
13 days
1952
17 days
1953
19 days
1954
8 days
1955
16 days
1956
16 days
1957
23 days
1958
13 days
1959
16 days
1960
12 days
1961
21 days
1962
12 days
1963
19 days
1964
13 days
1965
18 days
1966
12 days
1967
18 days
1968
17 days
1969
13 days
1970
18 days
1971
11 days
1972
13 days
1973
12 days
1974
10 days
1975
16 days
1976
16 days
1977
13 days
1978
17 days
1979
13 days
1980
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
67 years with a frost
Across 67 years with a frost, the median last spring frost at Brockville falls on 7 May and the median first autumn frost on 1 October, which leaves a median of 147 days between them.
In 1949 to 1979 the median growing season was 147 days. That is 3 days fewer than in 1873 to 1941.
Fitted over all years, the growing season changes by -0.1 days per decade at this station.
Frost dates and growing season at Brockville
Measure
Median, all years
Earliest period (1873 to 1941)
Recent period (1949 to 1979)
Recent against earliest
Fitted trend
Last spring frost
7 May
6 May
9 May
3 days later
+0.2 days per decade
First autumn frost
1 October
4 October
2 October
2 days earlier
+0.1 days per decade
Growing days
147 days
150 days
147 days
3 days fewer
-0.1 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
68 years, 1872 to 1979
A day with at least 43.9 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 100.7 mm (4.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Brockville: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
43.9 mm (1.7 in)
5 years
57.6 mm (2.3 in)
10 years
67.2 mm (2.6 in)
25 years
80.1 mm (3.2 in)
50 years
90.2 mm (3.6 in)
100 years
100.7 mm (4.0 in)
Longer than the 68 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, 68 years of values from 1872 to 1979.
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: 100.8 mm (4.0 in) in 1979; 89.4 mm (3.5 in) in 1951; 87.1 mm (3.4 in) in 1923.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Brockville, at 1948. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1948 ran 0.2 C (0.4 F) higher than in the years before (possible change).
Suspected changes in the annual mean temperature at Brockville, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1948
+0.2
+0.4
possible
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 Brockville standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Brockville 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.