Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Guelph Oac. 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 Guelph Oac, 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)
-37.2 C (-35.0 F)
n/a
n/a
Feb
13.9 C (57.0 F)
-32.8 C (-27.0 F)
n/a
n/a
Mar
24.4 C (75.9 F)
-28.9 C (-20.0 F)
n/a
n/a
Apr
28.9 C (84.0 F)
-16.1 C (3.0 F)
n/a
n/a
May
32.2 C (90.0 F)
-7.8 C (18.0 F)
n/a
n/a
Jun
35.0 C (95.0 F)
-1.1 C (30.0 F)
n/a
n/a
Jul
38.3 C (100.9 F)
1.7 C (35.1 F)
n/a
n/a
Aug
38.3 C (100.9 F)
-1.1 C (30.0 F)
n/a
n/a
Sep
36.7 C (98.1 F)
-6.7 C (19.9 F)
n/a
n/a
Oct
29.4 C (84.9 F)
-12.8 C (9.0 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Dec
16.1 C (61.0 F)
-31.1 C (-24.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Guelph Oac still stand. 1885 holds the most, with 33.
Standing records at Guelph Oac by the year they were set
Year set
Standing records
1881
23
1882
16
1883
19
1884
29
1885
33
1886
23
1887
20
1888
23
1889
27
1890
10
1891
28
1892
33
1893
26
1899
22
1900
29
1901
8
1902
12
1903
28
1904
20
1905
11
1906
13
1907
6
1908
16
1909
15
1910
21
1911
26
1912
9
1913
11
1914
20
1915
13
1916
18
1917
21
1918
16
1919
12
1920
20
1921
15
1922
9
1923
18
1924
9
1925
17
1926
20
1927
21
1928
10
1929
16
1930
22
1931
17
1932
16
1933
28
1934
22
1935
6
1936
27
1937
11
1938
19
1939
11
1940
16
1941
16
1942
13
1943
13
1944
10
1945
23
1946
22
1947
17
1948
15
1949
23
1950
18
1951
16
1952
10
1953
13
1954
12
1955
17
1956
15
1957
10
1958
9
1959
12
1960
9
1961
8
1962
11
1963
18
1964
20
1965
19
1966
14
1967
11
1968
8
1969
10
1970
5
1971
9
1972
18
1973
13
All-Time Record Progression
5 new records
5 all-time records were set at Guelph Oac between 6 August 1918 and 24 November 1950. Each dot is a new record.
When Guelph Oac set new all-time records
Date
Kind
Detail
1918-08-06
Record high maximum temperature
Record high maximum temperature 38.3 C (100.9 F)
1921-07-10
Record daily precipitation
Record daily precipitation 83.6 mm (3.3 in)
1934-02-08
Record low maximum temperature
Record low maximum temperature -25.6 C (-14.1 F)
1938-08-10
Record daily precipitation
Record daily precipitation 103.4 mm (4.1 in)
1950-11-24
Record daily snowfall
Record daily snowfall 55.1 cm (21.7 in)
Wettest Day of Each Month
Aug: 103.4 mm (4.1 in)
The wettest day on record for each calendar month at Guelph Oac. The most was 103.4 mm (4.1 in) on 10 August 1938.
Record daily precipitation for each month at Guelph Oac
Month
Record daily precipitation (mm)
Date
Jan
54.4 mm (2.1 in)
4 January 1922
Feb
63.5 mm (2.5 in)
5 February 1938
Mar
43.2 mm (1.7 in)
31 March 1926
Apr
45.2 mm (1.8 in)
2 April 1967
May
66.0 mm (2.6 in)
25 May 1953
Jun
74.7 mm (2.9 in)
11 June 1922
Jul
83.6 mm (3.3 in)
10 July 1921
Aug
103.4 mm (4.1 in)
10 August 1938
Sep
52.8 mm (2.1 in)
11 September 1922
Oct
95.8 mm (3.8 in)
15 October 1954
Nov
57.2 mm (2.3 in)
2 November 1940
Dec
50.3 mm (2.0 in)
12 December 1972
Period of Record Coverage
1881 to 1973
Complete yearUnder 90 percent of days
88 years of record at Guelph Oac, 1881 to 1973. 2 years have data for under 90 percent of days and are left out of rankings: 1881, 1890.
Cooler than the station meanWarmer than the station mean
One stripe for each of 83 complete years at Guelph Oac, 1882 to 1972. Blue stripes are years cooler than the station's own mean of 6.7 C (44.0 F); red stripes are warmer. The coolest year was 1904, at 4.8 C (40.6 F), and the warmest was 1921, at 8.5 C (47.3 F). The strongest colour marks a difference of 1.9 C (3.4 F).
Annual mean temperature at Guelph Oac as warming stripes, 1882 to 1972
Year
Annual mean temperature
Difference from the station mean
1882
7.4 C
+0.68 C
1883
5.5 C
-1.16 C
1884
6.3 C
-0.40 C
1886
6.1 C
-0.58 C
1887
6.4 C
-0.33 C
1888
5.5 C
-1.17 C
1889
6.7 C
+0.04 C
1891
7.6 C
+0.91 C
1893
5.0 C
-1.66 C
1899
7.1 C
+0.46 C
1900
7.8 C
+1.10 C
1901
6.5 C
-0.23 C
1902
6.4 C
-0.24 C
1903
6.8 C
+0.10 C
1904
4.8 C
-1.90 C
1905
6.5 C
-0.21 C
1906
7.4 C
+0.73 C
1907
6.4 C
-0.28 C
1908
7.4 C
+0.69 C
1909
6.8 C
+0.14 C
1910
6.9 C
+0.23 C
1911
7.6 C
+0.91 C
1912
6.0 C
-0.65 C
1913
7.9 C
+1.17 C
1914
6.8 C
+0.14 C
1915
7.0 C
+0.36 C
1916
6.9 C
+0.22 C
1917
4.8 C
-1.89 C
1918
6.8 C
+0.11 C
1919
7.6 C
+0.89 C
1920
6.0 C
-0.67 C
1921
8.5 C
+1.83 C
1922
7.4 C
+0.72 C
1923
6.3 C
-0.42 C
1924
5.4 C
-1.31 C
1925
6.2 C
-0.52 C
1926
4.9 C
-1.78 C
1927
6.8 C
+0.12 C
1928
6.5 C
-0.20 C
1929
6.0 C
-0.73 C
1930
6.8 C
+0.13 C
1931
8.1 C
+1.39 C
1932
7.1 C
+0.42 C
1933
7.3 C
+0.65 C
1934
6.3 C
-0.39 C
1935
6.3 C
-0.39 C
1936
6.4 C
-0.25 C
1937
7.0 C
+0.29 C
1938
7.7 C
+1.06 C
1939
6.9 C
+0.25 C
1940
5.7 C
-0.96 C
1941
7.6 C
+0.89 C
1942
6.9 C
+0.22 C
1943
5.9 C
-0.77 C
1944
6.6 C
-0.06 C
1945
6.3 C
-0.35 C
1946
7.5 C
+0.84 C
1947
7.1 C
+0.42 C
1948
7.3 C
+0.60 C
1949
8.3 C
+1.62 C
1950
6.5 C
-0.22 C
1951
7.1 C
+0.40 C
1952
7.7 C
+1.00 C
1953
8.1 C
+1.37 C
1954
7.0 C
+0.30 C
1955
7.7 C
+0.99 C
1956
6.5 C
-0.20 C
1957
6.9 C
+0.19 C
1958
6.3 C
-0.34 C
1959
7.2 C
+0.49 C
1960
6.5 C
-0.14 C
1961
6.9 C
+0.21 C
1962
6.2 C
-0.52 C
1963
5.9 C
-0.83 C
1964
6.6 C
-0.11 C
1965
5.8 C
-0.84 C
1966
6.4 C
-0.33 C
1967
6.0 C
-0.67 C
1968
6.5 C
-0.19 C
1969
6.7 C
+0.00 C
1970
6.3 C
-0.38 C
1971
6.7 C
-0.03 C
1972
5.6 C
-1.10 C
The fitted trend in annual mean temperature here over 1882 to 1972 is 0.02 C (-0.05 to 0.09) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.03 F (-0.09 to 0.15) per decade. The slope is a straight line fitted to 83 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Guelph Oac
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.02 C (-0.05 to 0.09) per decade
0.03 F (-0.09 to 0.15) per decade
1882 to 1972
83
Not clearly different from zero
Mean daily maximum
-0.05 C (-0.12 to 0.03) per decade
-0.08 F (-0.22 to 0.05) per decade
1882 to 1972
83
Not clearly different from zero
Mean daily minimum
0.08 C (0.01 to 0.16) per decade
0.15 F (0.01 to 0.29) per decade
1882 to 1972
83
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
1881 to 1973
Yearly extremes at Guelph Oac: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
38.3 C (100.9 F)
1918
32.8 C (91.0 F)
88
Coldest night (TNn)
-37.2 C (-35.0 F)
1884
-25.6 C (-14.1 F)
88
Wettest day (Rx1day)
103.4 mm (4.1 in)
1938
43.2 mm (1.7 in)
88
Wettest five days (Rx5day)
164.2 mm (6.5 in)
1954
65.3 mm (2.6 in)
88
Longest dry spell (CDD)
38 days
1885
18 days
88
Hottest day (TXx)
The hottest day of the year at Guelph Oac, 1881 to 1973. The record is 38.3 C (100.9 F) in 1918, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Guelph Oac by year
Year
Hottest day (TXx)
1881
36.7 C (98.1 F)
1882
32.2 C (90.0 F)
1883
31.7 C (89.1 F)
1884
33.9 C (93.0 F)
1885
32.2 C (90.0 F)
1886
33.3 C (91.9 F)
1887
35.6 C (96.1 F)
1888
35.0 C (95.0 F)
1889
31.7 C (89.1 F)
1890
36.7 C (98.1 F)
1891
35.0 C (95.0 F)
1892
33.3 C (91.9 F)
1893
34.4 C (93.9 F)
1899
35.0 C (95.0 F)
1900
35.6 C (96.1 F)
1901
34.4 C (93.9 F)
1902
31.7 C (89.1 F)
1903
32.2 C (90.0 F)
1904
32.2 C (90.0 F)
1905
31.7 C (89.1 F)
1906
31.7 C (89.1 F)
1907
31.1 C (88.0 F)
1908
31.7 C (89.1 F)
1909
34.4 C (93.9 F)
1910
33.9 C (93.0 F)
1911
37.2 C (99.0 F)
1912
31.7 C (89.1 F)
1913
35.0 C (95.0 F)
1914
33.9 C (93.0 F)
1915
30.0 C (86.0 F)
1916
36.1 C (97.0 F)
1917
34.4 C (93.9 F)
1918
38.3 C (100.9 F)
1919
34.4 C (93.9 F)
1920
31.7 C (89.1 F)
1921
34.4 C (93.9 F)
1922
32.8 C (91.0 F)
1923
32.8 C (91.0 F)
1924
32.8 C (91.0 F)
1925
32.2 C (90.0 F)
1926
33.3 C (91.9 F)
1927
32.2 C (90.0 F)
1928
31.1 C (88.0 F)
1929
32.8 C (91.0 F)
1930
33.3 C (91.9 F)
1931
36.1 C (97.0 F)
1932
32.2 C (90.0 F)
1933
35.6 C (96.1 F)
1934
33.9 C (93.0 F)
1935
32.2 C (90.0 F)
1936
38.3 C (100.9 F)
1937
32.2 C (90.0 F)
1938
32.8 C (91.0 F)
1939
34.4 C (93.9 F)
1940
31.7 C (89.1 F)
1941
34.4 C (93.9 F)
1942
32.2 C (90.0 F)
1943
31.7 C (89.1 F)
1944
34.4 C (93.9 F)
1945
32.2 C (90.0 F)
1946
33.3 C (91.9 F)
1947
34.4 C (93.9 F)
1948
35.6 C (96.1 F)
1949
35.0 C (95.0 F)
1950
32.2 C (90.0 F)
1951
32.2 C (90.0 F)
1952
34.4 C (93.9 F)
1953
35.0 C (95.0 F)
1954
31.1 C (88.0 F)
1955
36.7 C (98.1 F)
1956
32.2 C (90.0 F)
1957
32.2 C (90.0 F)
1958
31.1 C (88.0 F)
1959
32.8 C (91.0 F)
1960
31.1 C (88.0 F)
1961
30.0 C (86.0 F)
1962
31.1 C (88.0 F)
1963
33.3 C (91.9 F)
1964
32.8 C (91.0 F)
1965
32.2 C (90.0 F)
1966
33.9 C (93.0 F)
1967
31.1 C (88.0 F)
1968
31.7 C (89.1 F)
1969
32.2 C (90.0 F)
1970
30.6 C (87.1 F)
1971
33.3 C (91.9 F)
1972
31.1 C (88.0 F)
1973
33.9 C (93.0 F)
Coldest night (TNn)
The coldest night of the year at Guelph Oac, 1881 to 1973. The record is -37.2 C (-35.0 F) in 1884, marked on the chart; the median year is -25.6 C (-14.1 F).
Coldest night (TNn) at Guelph Oac by year
Year
Coldest night (TNn)
1881
-13.3 C (8.1 F)
1882
-24.4 C (-11.9 F)
1883
-26.7 C (-16.1 F)
1884
-37.2 C (-35.0 F)
1885
-28.9 C (-20.0 F)
1886
-31.1 C (-24.0 F)
1887
-25.6 C (-14.1 F)
1888
-28.3 C (-18.9 F)
1889
-28.3 C (-18.9 F)
1890
-20.0 C (-4.0 F)
1891
-18.3 C (-0.9 F)
1892
-28.9 C (-20.0 F)
1893
-32.2 C (-26.0 F)
1899
-29.4 C (-20.9 F)
1900
-26.1 C (-15.0 F)
1901
-25.6 C (-14.1 F)
1902
-21.7 C (-7.1 F)
1903
-23.3 C (-9.9 F)
1904
-31.7 C (-25.1 F)
1905
-26.1 C (-15.0 F)
1906
-26.1 C (-15.0 F)
1907
-26.1 C (-15.0 F)
1908
-28.3 C (-18.9 F)
1909
-24.4 C (-11.9 F)
1910
-25.6 C (-14.1 F)
1911
-18.3 C (-0.9 F)
1912
-29.4 C (-20.9 F)
1913
-20.6 C (-5.1 F)
1914
-30.6 C (-23.1 F)
1915
-20.6 C (-5.1 F)
1916
-30.0 C (-22.0 F)
1917
-26.7 C (-16.1 F)
1918
-31.7 C (-25.1 F)
1919
-22.2 C (-8.0 F)
1920
-28.9 C (-20.0 F)
1921
-23.9 C (-11.0 F)
1922
-21.1 C (-6.0 F)
1923
-24.4 C (-11.9 F)
1924
-23.9 C (-11.0 F)
1925
-30.0 C (-22.0 F)
1926
-26.1 C (-15.0 F)
1927
-26.7 C (-16.1 F)
1928
-28.9 C (-20.0 F)
1929
-30.0 C (-22.0 F)
1930
-25.0 C (-13.0 F)
1931
-22.2 C (-8.0 F)
1932
-17.8 C (0.0 F)
1933
-28.3 C (-18.9 F)
1934
-32.8 C (-27.0 F)
1935
-25.6 C (-14.1 F)
1936
-25.6 C (-14.1 F)
1937
-18.3 C (-0.9 F)
1938
-21.7 C (-7.1 F)
1939
-27.8 C (-18.0 F)
1940
-26.1 C (-15.0 F)
1941
-28.3 C (-18.9 F)
1942
-31.1 C (-24.0 F)
1943
-29.4 C (-20.9 F)
1944
-26.7 C (-16.1 F)
1945
-29.4 C (-20.9 F)
1946
-23.9 C (-11.0 F)
1947
-19.4 C (-2.9 F)
1948
-30.6 C (-23.1 F)
1949
-21.1 C (-6.0 F)
1950
-26.7 C (-16.1 F)
1951
-21.7 C (-7.1 F)
1952
-22.8 C (-9.0 F)
1953
-19.4 C (-2.9 F)
1954
-23.9 C (-11.0 F)
1955
-24.4 C (-11.9 F)
1956
-20.6 C (-5.1 F)
1957
-26.1 C (-15.0 F)
1958
-25.0 C (-13.0 F)
1959
-24.4 C (-11.9 F)
1960
-23.3 C (-9.9 F)
1961
-25.0 C (-13.0 F)
1962
-23.9 C (-11.0 F)
1963
-28.9 C (-20.0 F)
1964
-23.9 C (-11.0 F)
1965
-26.7 C (-16.1 F)
1966
-26.1 C (-15.0 F)
1967
-30.0 C (-22.0 F)
1968
-25.6 C (-14.1 F)
1969
-21.1 C (-6.0 F)
1970
-28.3 C (-18.9 F)
1971
-23.9 C (-11.0 F)
1972
-23.3 C (-9.9 F)
1973
-22.2 C (-8.0 F)
Wettest day (Rx1day)
The wettest day of the year at Guelph Oac, 1881 to 1973. The record is 103.4 mm (4.1 in) in 1938, marked on the chart; the median year is 43.2 mm (1.7 in).
Wettest day (Rx1day) at Guelph Oac by year
Year
Wettest day (Rx1day)
1881
31.5 mm (1.2 in)
1882
48.3 mm (1.9 in)
1883
43.2 mm (1.7 in)
1884
43.2 mm (1.7 in)
1885
30.2 mm (1.2 in)
1886
36.3 mm (1.4 in)
1887
44.2 mm (1.7 in)
1888
32.5 mm (1.3 in)
1889
38.1 mm (1.5 in)
1890
36.8 mm (1.4 in)
1891
57.2 mm (2.3 in)
1892
35.6 mm (1.4 in)
1893
53.3 mm (2.1 in)
1899
29.5 mm (1.2 in)
1900
43.2 mm (1.7 in)
1901
41.4 mm (1.6 in)
1902
49.5 mm (1.9 in)
1903
35.1 mm (1.4 in)
1904
53.8 mm (2.1 in)
1905
42.9 mm (1.7 in)
1906
60.2 mm (2.4 in)
1907
37.3 mm (1.5 in)
1908
28.2 mm (1.1 in)
1909
42.9 mm (1.7 in)
1910
33.3 mm (1.3 in)
1911
30.0 mm (1.2 in)
1912
51.3 mm (2.0 in)
1913
35.3 mm (1.4 in)
1914
40.4 mm (1.6 in)
1915
42.2 mm (1.7 in)
1916
48.8 mm (1.9 in)
1917
45.7 mm (1.8 in)
1918
49.5 mm (1.9 in)
1919
49.5 mm (1.9 in)
1920
43.2 mm (1.7 in)
1921
83.6 mm (3.3 in)
1922
74.7 mm (2.9 in)
1923
45.7 mm (1.8 in)
1924
36.8 mm (1.4 in)
1925
35.6 mm (1.4 in)
1926
50.8 mm (2.0 in)
1927
55.9 mm (2.2 in)
1928
38.1 mm (1.5 in)
1929
35.6 mm (1.4 in)
1930
35.8 mm (1.4 in)
1931
30.5 mm (1.2 in)
1932
43.2 mm (1.7 in)
1933
31.8 mm (1.3 in)
1934
31.8 mm (1.3 in)
1935
44.2 mm (1.7 in)
1936
59.7 mm (2.4 in)
1937
48.0 mm (1.9 in)
1938
103.4 mm (4.1 in)
1939
31.0 mm (1.2 in)
1940
57.2 mm (2.3 in)
1941
48.3 mm (1.9 in)
1942
54.4 mm (2.1 in)
1943
35.6 mm (1.4 in)
1944
50.8 mm (2.0 in)
1945
47.0 mm (1.9 in)
1946
22.9 mm (0.9 in)
1947
50.8 mm (2.0 in)
1948
37.1 mm (1.5 in)
1949
46.5 mm (1.8 in)
1950
55.1 mm (2.2 in)
1951
62.0 mm (2.4 in)
1952
41.1 mm (1.6 in)
1953
66.0 mm (2.6 in)
1954
95.8 mm (3.8 in)
1955
49.0 mm (1.9 in)
1956
57.7 mm (2.3 in)
1957
51.3 mm (2.0 in)
1958
42.4 mm (1.7 in)
1959
28.4 mm (1.1 in)
1960
35.1 mm (1.4 in)
1961
59.9 mm (2.4 in)
1962
31.8 mm (1.3 in)
1963
31.8 mm (1.3 in)
1964
51.3 mm (2.0 in)
1965
40.6 mm (1.6 in)
1966
46.2 mm (1.8 in)
1967
45.2 mm (1.8 in)
1968
79.5 mm (3.1 in)
1969
46.2 mm (1.8 in)
1970
33.5 mm (1.3 in)
1971
61.0 mm (2.4 in)
1972
50.3 mm (2.0 in)
1973
33.3 mm (1.3 in)
Wettest five days (Rx5day)
The wettest five days of the year at Guelph Oac, 1881 to 1973. The record is 164.2 mm (6.5 in) in 1954, marked on the chart; the median year is 65.3 mm (2.6 in).
Wettest five days (Rx5day) at Guelph Oac by year
Year
Wettest five days (Rx5day)
1881
49.3 mm (1.9 in)
1882
50.5 mm (2.0 in)
1883
43.5 mm (1.7 in)
1884
56.8 mm (2.2 in)
1885
33.3 mm (1.3 in)
1886
47.2 mm (1.9 in)
1887
44.2 mm (1.7 in)
1888
50.7 mm (2.0 in)
1889
70.1 mm (2.8 in)
1890
63.8 mm (2.5 in)
1891
61.0 mm (2.4 in)
1892
53.9 mm (2.1 in)
1893
54.4 mm (2.1 in)
1899
37.9 mm (1.5 in)
1900
51.4 mm (2.0 in)
1901
75.4 mm (3.0 in)
1902
65.3 mm (2.6 in)
1903
59.4 mm (2.3 in)
1904
74.7 mm (2.9 in)
1905
53.9 mm (2.1 in)
1906
62.4 mm (2.5 in)
1907
59.4 mm (2.3 in)
1908
52.4 mm (2.1 in)
1909
53.6 mm (2.1 in)
1910
56.7 mm (2.2 in)
1911
40.1 mm (1.6 in)
1912
115.1 mm (4.5 in)
1913
43.0 mm (1.7 in)
1914
62.0 mm (2.4 in)
1915
72.5 mm (2.9 in)
1916
83.6 mm (3.3 in)
1917
104.9 mm (4.1 in)
1918
55.9 mm (2.2 in)
1919
71.7 mm (2.8 in)
1920
55.6 mm (2.2 in)
1921
113.3 mm (4.5 in)
1922
81.8 mm (3.2 in)
1923
65.3 mm (2.6 in)
1924
68.4 mm (2.7 in)
1925
67.9 mm (2.7 in)
1926
121.9 mm (4.8 in)
1927
109.7 mm (4.3 in)
1928
64.8 mm (2.6 in)
1929
62.9 mm (2.5 in)
1930
56.1 mm (2.2 in)
1931
35.6 mm (1.4 in)
1932
57.4 mm (2.3 in)
1933
56.7 mm (2.2 in)
1934
72.5 mm (2.9 in)
1935
77.5 mm (3.1 in)
1936
74.7 mm (2.9 in)
1937
65.3 mm (2.6 in)
1938
105.9 mm (4.2 in)
1939
49.0 mm (1.9 in)
1940
78.8 mm (3.1 in)
1941
56.1 mm (2.2 in)
1942
77.5 mm (3.1 in)
1943
70.2 mm (2.8 in)
1944
53.6 mm (2.1 in)
1945
78.4 mm (3.1 in)
1946
44.4 mm (1.7 in)
1947
69.4 mm (2.7 in)
1948
86.8 mm (3.4 in)
1949
69.1 mm (2.7 in)
1950
93.9 mm (3.7 in)
1951
81.1 mm (3.2 in)
1952
69.6 mm (2.7 in)
1953
98.5 mm (3.9 in)
1954
164.2 mm (6.5 in)
1955
55.7 mm (2.2 in)
1956
99.4 mm (3.9 in)
1957
98.0 mm (3.9 in)
1958
80.2 mm (3.2 in)
1959
61.7 mm (2.4 in)
1960
74.6 mm (2.9 in)
1961
73.9 mm (2.9 in)
1962
56.3 mm (2.2 in)
1963
38.4 mm (1.5 in)
1964
65.0 mm (2.6 in)
1965
66.3 mm (2.6 in)
1966
84.3 mm (3.3 in)
1967
82.3 mm (3.2 in)
1968
92.5 mm (3.6 in)
1969
46.5 mm (1.8 in)
1970
52.0 mm (2.0 in)
1971
73.2 mm (2.9 in)
1972
66.3 mm (2.6 in)
1973
73.3 mm (2.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at Guelph Oac, 1881 to 1973. The record is 38 days in 1885, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Guelph Oac by year
Year
Longest dry spell (CDD)
1881
19 days
1882
29 days
1883
22 days
1884
17 days
1885
38 days
1886
17 days
1887
17 days
1888
15 days
1889
24 days
1890
24 days
1891
19 days
1892
19 days
1893
18 days
1899
21 days
1900
26 days
1901
15 days
1902
19 days
1903
23 days
1904
29 days
1905
18 days
1906
17 days
1907
15 days
1908
25 days
1909
18 days
1910
34 days
1911
27 days
1912
35 days
1913
18 days
1914
16 days
1915
17 days
1916
29 days
1917
14 days
1918
16 days
1919
24 days
1920
16 days
1921
23 days
1922
22 days
1923
20 days
1924
35 days
1925
11 days
1926
13 days
1927
25 days
1928
17 days
1929
20 days
1930
12 days
1931
15 days
1932
17 days
1933
19 days
1934
18 days
1935
17 days
1936
22 days
1937
12 days
1938
12 days
1939
20 days
1940
12 days
1941
16 days
1942
17 days
1943
32 days
1944
17 days
1945
14 days
1946
16 days
1947
21 days
1948
19 days
1949
22 days
1950
15 days
1951
14 days
1952
13 days
1953
11 days
1954
19 days
1955
18 days
1956
19 days
1957
22 days
1958
22 days
1959
13 days
1960
14 days
1961
21 days
1962
24 days
1963
33 days
1964
18 days
1965
11 days
1966
20 days
1967
21 days
1968
13 days
1969
16 days
1970
16 days
1971
22 days
1972
13 days
1973
27 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
83 years with a frost
Across 83 years with a frost, the median last spring frost at Guelph Oac falls on 15 May and the median first autumn frost on 28 September, which leaves a median of 140 days between them.
In 1943 to 1972 the median growing season was 138 days. That is 4 days fewer than in 1882 to 1919.
Fitted over all years, the growing season changes by -0.4 days per decade at this station.
Frost dates and growing season at Guelph Oac
Measure
Median, all years
Earliest period (1882 to 1919)
Recent period (1943 to 1972)
Recent against earliest
Fitted trend
Last spring frost
15 May
15 May
14 May
1 day earlier
+0.2 days per decade
First autumn frost
28 September
28 September
28 September
no change
-0.2 days per decade
Growing days
140 days
142 days
138 days
4 days fewer
-0.4 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
86 years, 1882 to 1973
A day with at least 43.2 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 93.2 mm (3.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Guelph Oac: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
43.2 mm (1.7 in)
5 years
55.2 mm (2.2 in)
10 years
63.7 mm (2.5 in)
25 years
75.0 mm (3.0 in)
50 years
83.9 mm (3.3 in)
100 years
93.2 mm (3.7 in)
Longer than the 86 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, 86 years of values from 1882 to 1973.
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: 103.4 mm (4.1 in) in 1938; 95.8 mm (3.8 in) in 1954; 83.6 mm (3.3 in) in 1921.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Guelph Oac, at 1962. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1962 ran 0.2 C (0.4 F) lower than in the years before (possible change).
Suspected changes in the annual mean temperature at Guelph Oac, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1962
-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 Guelph Oac standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Guelph Oac 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.