Record envelope, standing records and threshold days for Ontario Ksrv (USC00356294), Oregon, United States, with 109 years of record.
Key Facts for Ontario Ksrv
Ontario Ksrv (USC00356294) is a weather station in Oregon, United States at 44.04 latitude and -116.97 longitude, 654 m (2,145 ft) above sea level.
The station reports from 1903 to 2011, 109 years of record.
1,464 records set at Ontario Ksrv still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Ontario Ksrv set a daily record high maximum temperature of 18.3 C (64.9 F) on 16 February 2011.
About the Station
Location: Oregon, United States, 44.04 latitude, -116.97 longitude.
Elevation: 654 m (2,145 ft).
Period of record: 1903 to 2011, 109 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
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 Ontario Ksrv. 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 Ontario Ksrv, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.8 C (64.0 F)
-31.7 C (-25.1 F)
n/a
n/a
Feb
19.4 C (66.9 F)
-31.1 C (-24.0 F)
n/a
n/a
Mar
29.4 C (84.9 F)
-12.8 C (9.0 F)
n/a
n/a
Apr
34.4 C (93.9 F)
-8.3 C (17.1 F)
n/a
n/a
May
39.4 C (102.9 F)
-3.9 C (25.0 F)
n/a
n/a
Jun
42.2 C (108.0 F)
-0.6 C (30.9 F)
n/a
n/a
Jul
45.0 C (113.0 F)
1.1 C (34.0 F)
n/a
n/a
Aug
45.0 C (113.0 F)
0.6 C (33.1 F)
n/a
n/a
Sep
40.0 C (104.0 F)
-4.4 C (24.1 F)
n/a
n/a
Oct
34.4 C (93.9 F)
-10.0 C (14.0 F)
n/a
n/a
Nov
25.6 C (78.1 F)
-21.1 C (-6.0 F)
n/a
n/a
Dec
18.9 C (66.0 F)
-30.6 C (-23.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Ontario Ksrv still stand. 1966 holds the most, with 58.
Standing records at Ontario Ksrv by the year they were set
Year set
Standing records
1945
10
1946
13
1947
11
1948
21
1949
31
1950
31
1951
16
1952
21
1953
24
1954
29
1955
18
1956
26
1957
28
1958
25
1959
26
1960
40
1961
31
1962
29
1963
24
1964
23
1965
36
1966
58
1967
29
1968
31
1969
21
1970
30
1971
36
1972
38
1973
18
1974
30
1975
25
1976
18
1977
36
1978
21
1979
17
1980
17
1981
14
1982
15
1983
22
1984
23
1985
46
1986
22
1987
18
1988
19
1989
31
1990
26
1991
14
1992
16
1993
44
1994
14
1995
20
1996
17
1997
7
1998
14
1999
18
2000
7
2001
13
2002
23
2003
22
2004
1
2005
9
2006
9
2007
6
2008
11
2009
7
2010
16
2011
2
All-Time Record Progression
6 new records
6 all-time records were set at Ontario Ksrv between 11 January 1979 and 8 January 1993. Each dot is a new record.
When Ontario Ksrv set new all-time records
Date
Kind
Detail
1979-01-11
Record snow depth
Record snow depth 33.0 cm (13.0 in)
1979-01-14
Record snow depth
Record snow depth 50.8 cm (20.0 in)
1983-07-31
Record high minimum temperature
Record high minimum temperature 25.6 C (78.1 F)
1989-02-06
Record low maximum temperature
Record low maximum temperature -17.2 C (1.0 F)
1990-12-22
Record low maximum temperature
Record low maximum temperature -18.3 C (-0.9 F)
1993-01-08
Record daily snowfall
Record daily snowfall 25.4 cm (10.0 in)
Wettest Day of Each Month
Apr: 61.0 mm (2.4 in)
The wettest day on record for each calendar month at Ontario Ksrv. The most was 61.0 mm (2.4 in) on 17 April 1905.
Record daily precipitation for each month at Ontario Ksrv
Month
Record daily precipitation (mm)
Date
Jan
34.3 mm (1.4 in)
8 January 1993
Feb
50.8 mm (2.0 in)
24 February 1904
Mar
26.7 mm (1.1 in)
4 March 1983
Apr
61.0 mm (2.4 in)
17 April 1905
May
39.6 mm (1.6 in)
22 May 1998
Jun
22.1 mm (0.9 in)
12 June 1992
Jul
17.3 mm (0.7 in)
10 July 1997
Aug
30.0 mm (1.2 in)
14 August 1979
Sep
40.4 mm (1.6 in)
14 September 1959
Oct
26.2 mm (1.0 in)
30 October 1982
Nov
20.8 mm (0.8 in)
24 November 1997
Dec
35.6 mm (1.4 in)
24 December 1968
Period of Record Coverage
1945 to 2011
Complete yearUnder 90 percent of days
67 years of record at Ontario Ksrv, 1945 to 2011. 17 years have data for under 90 percent of days and are left out of rankings: 1945, 1947, 1955, 1986, 1987, 1988, 1989, 1990 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 54 complete years at Ontario Ksrv, 1948 to 2010. Blue stripes are years cooler than the station's own mean of 10.7 C (51.3 F); red stripes are warmer. The coolest year was 1985, at 8.4 C (47.1 F), and the warmest was 1966, at 12.3 C (54.1 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at Ontario Ksrv as warming stripes, 1948 to 2010
Year
Annual mean temperature
Difference from the station mean
1948
10.0 C
-0.79 C
1949
9.9 C
-0.80 C
1950
10.1 C
-0.61 C
1951
10.0 C
-0.76 C
1952
10.0 C
-0.76 C
1953
11.1 C
+0.38 C
1954
10.6 C
-0.15 C
1956
10.7 C
-0.01 C
1957
10.5 C
-0.20 C
1958
11.9 C
+1.19 C
1959
11.3 C
+0.60 C
1960
11.1 C
+0.37 C
1961
12.1 C
+1.32 C
1962
10.8 C
+0.09 C
1963
11.6 C
+0.82 C
1964
10.0 C
-0.79 C
1965
11.3 C
+0.60 C
1966
12.3 C
+1.53 C
1967
11.9 C
+1.12 C
1968
11.5 C
+0.73 C
1969
11.3 C
+0.53 C
1970
11.2 C
+0.46 C
1971
11.4 C
+0.61 C
1972
11.0 C
+0.22 C
1973
12.0 C
+1.30 C
1974
11.3 C
+0.53 C
1975
10.1 C
-0.64 C
1976
9.8 C
-0.99 C
1977
10.6 C
-0.12 C
1978
10.6 C
-0.12 C
1979
10.5 C
-0.29 C
1980
10.8 C
+0.08 C
1981
11.4 C
+0.67 C
1982
9.4 C
-1.35 C
1983
10.9 C
+0.14 C
1984
9.5 C
-1.29 C
1985
8.4 C
-2.36 C
1986
10.6 C
-0.16 C
1987
11.3 C
+0.59 C
1988
10.9 C
+0.15 C
1989
9.2 C
-1.56 C
1990
11.2 C
+0.47 C
1991
10.6 C
-0.10 C
1992
11.7 C
+0.92 C
1993
8.9 C
-1.87 C
1994
10.8 C
+0.10 C
1995
10.7 C
-0.08 C
1996
10.7 C
-0.06 C
1999
10.6 C
-0.13 C
2001
11.0 C
+0.25 C
2002
10.6 C
-0.15 C
2003
11.7 C
+0.94 C
2008
10.4 C
-0.39 C
2010
10.5 C
-0.23 C
The fitted trend in annual mean temperature here over 1948 to 2010 is -0.1 C (-0.2 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.3 to 0.2) per decade. The slope is a straight line fitted to 54 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Ontario Ksrv
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.2 to 0.1) per decade
-0.1 F (-0.3 to 0.2) per decade
1948 to 2010
54
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.3 to 0.1) per decade
-0.2 F (-0.5 to 0.2) per decade
1948 to 2010
54
Not clearly different from zero
Mean daily minimum
-0.01 C (-0.13 to 0.11) per decade
-0.02 F (-0.23 to 0.19) per decade
1948 to 2010
54
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
1903 to 2011
Yearly extremes at Ontario Ksrv: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.0 C (113.0 F)
1961
41.1 C (106.0 F)
67
Coldest night (TNn)
-31.7 C (-25.1 F)
1957
-20.0 C (-4.0 F)
67
Wettest day (Rx1day)
61.0 mm (2.4 in)
1905
17.0 mm (0.7 in)
73
Wettest five days (Rx5day)
70.5 mm (2.8 in)
2005
30.2 mm (1.2 in)
73
Longest dry spell (CDD)
153 days
1999
54 days
73
Hottest day (TXx)
The hottest day of the year at Ontario Ksrv, 1903 to 2011. The record is 45.0 C (113.0 F) in 1961, marked on the chart; the median year is 41.1 C (106.0 F).
Hottest day (TXx) at Ontario Ksrv by year
Year
Hottest day (TXx)
1903
n/a
1904
n/a
1905
n/a
1906
n/a
1907
n/a
1908
n/a
1945
37.8 C (100.0 F)
1946
41.1 C (106.0 F)
1947
38.9 C (102.0 F)
1948
37.8 C (100.0 F)
1949
40.6 C (105.1 F)
1950
37.8 C (100.0 F)
1951
38.9 C (102.0 F)
1952
39.4 C (102.9 F)
1953
41.7 C (107.1 F)
1954
38.9 C (102.0 F)
1955
20.6 C (69.1 F)
1956
41.7 C (107.1 F)
1957
40.0 C (104.0 F)
1958
41.1 C (106.0 F)
1959
43.9 C (111.0 F)
1960
44.4 C (111.9 F)
1961
45.0 C (113.0 F)
1962
41.7 C (107.1 F)
1963
40.0 C (104.0 F)
1964
41.7 C (107.1 F)
1965
41.1 C (106.0 F)
1966
42.2 C (108.0 F)
1967
45.0 C (113.0 F)
1968
42.8 C (109.0 F)
1969
41.1 C (106.0 F)
1970
42.2 C (108.0 F)
1971
43.3 C (109.9 F)
1972
43.3 C (109.9 F)
1973
43.3 C (109.9 F)
1974
41.1 C (106.0 F)
1975
40.6 C (105.1 F)
1976
40.0 C (104.0 F)
1977
40.6 C (105.1 F)
1978
41.1 C (106.0 F)
1979
41.1 C (106.0 F)
1980
40.6 C (105.1 F)
1981
40.0 C (104.0 F)
1982
38.9 C (102.0 F)
1983
41.1 C (106.0 F)
1984
40.6 C (105.1 F)
1985
41.7 C (107.1 F)
1986
39.4 C (102.9 F)
1987
39.4 C (102.9 F)
1988
41.1 C (106.0 F)
1989
40.0 C (104.0 F)
1990
41.7 C (107.1 F)
1991
39.4 C (102.9 F)
1992
41.7 C (107.1 F)
1993
36.1 C (97.0 F)
1994
41.7 C (107.1 F)
1995
39.4 C (102.9 F)
1996
41.7 C (107.1 F)
1997
40.0 C (104.0 F)
1998
41.1 C (106.0 F)
1999
41.1 C (106.0 F)
2000
41.1 C (106.0 F)
2001
43.3 C (109.9 F)
2002
44.4 C (111.9 F)
2003
43.9 C (111.0 F)
2004
31.7 C (89.1 F)
2005
41.1 C (106.0 F)
2006
43.3 C (109.9 F)
2007
40.6 C (105.1 F)
2008
37.8 C (100.0 F)
2009
38.9 C (102.0 F)
2010
38.9 C (102.0 F)
2011
18.3 C (64.9 F)
Coldest night (TNn)
The coldest night of the year at Ontario Ksrv, 1903 to 2011. The record is -31.7 C (-25.1 F) in 1957, marked on the chart; the median year is -20.0 C (-4.0 F).
Coldest night (TNn) at Ontario Ksrv by year
Year
Coldest night (TNn)
1903
n/a
1904
n/a
1905
n/a
1906
n/a
1907
n/a
1908
n/a
1945
-22.2 C (-8.0 F)
1946
-12.8 C (9.0 F)
1947
-9.4 C (15.1 F)
1948
-22.8 C (-9.0 F)
1949
-29.4 C (-20.9 F)
1950
-28.3 C (-18.9 F)
1951
-18.9 C (-2.0 F)
1952
-20.0 C (-4.0 F)
1953
-9.4 C (15.1 F)
1954
-14.4 C (6.1 F)
1955
-16.7 C (1.9 F)
1956
-23.9 C (-11.0 F)
1957
-31.7 C (-25.1 F)
1958
-14.4 C (6.1 F)
1959
-20.0 C (-4.0 F)
1960
-20.6 C (-5.1 F)
1961
-15.0 C (5.0 F)
1962
-31.7 C (-25.1 F)
1963
-21.1 C (-6.0 F)
1964
-23.9 C (-11.0 F)
1965
-16.7 C (1.9 F)
1966
-11.1 C (12.0 F)
1967
-20.6 C (-5.1 F)
1968
-15.0 C (5.0 F)
1969
-13.3 C (8.1 F)
1970
-16.7 C (1.9 F)
1971
-15.6 C (3.9 F)
1972
-30.6 C (-23.1 F)
1973
-12.8 C (9.0 F)
1974
-21.7 C (-7.1 F)
1975
-20.6 C (-5.1 F)
1976
-20.6 C (-5.1 F)
1977
-25.6 C (-14.1 F)
1978
-23.3 C (-9.9 F)
1979
-28.3 C (-18.9 F)
1980
-22.2 C (-8.0 F)
1981
-15.6 C (3.9 F)
1982
-24.4 C (-11.9 F)
1983
-23.3 C (-9.9 F)
1984
-23.9 C (-11.0 F)
1985
-26.7 C (-16.1 F)
1986
-17.8 C (0.0 F)
1987
-17.2 C (1.0 F)
1988
-21.7 C (-7.1 F)
1989
-31.1 C (-24.0 F)
1990
-28.9 C (-20.0 F)
1991
-20.6 C (-5.1 F)
1992
-23.9 C (-11.0 F)
1993
-21.1 C (-6.0 F)
1994
-17.2 C (1.0 F)
1995
-18.9 C (-2.0 F)
1996
-16.7 C (1.9 F)
1997
-9.4 C (15.1 F)
1998
-10.6 C (12.9 F)
1999
-11.7 C (10.9 F)
2000
-13.3 C (8.1 F)
2001
-12.2 C (10.0 F)
2002
-13.3 C (8.1 F)
2003
-11.7 C (10.9 F)
2004
-18.3 C (-0.9 F)
2005
-20.0 C (-4.0 F)
2006
-13.3 C (8.1 F)
2007
-15.6 C (3.9 F)
2008
-20.0 C (-4.0 F)
2009
-20.0 C (-4.0 F)
2010
-15.0 C (5.0 F)
2011
-17.8 C (0.0 F)
Wettest day (Rx1day)
The wettest day of the year at Ontario Ksrv, 1903 to 2011. The record is 61.0 mm (2.4 in) in 1905, marked on the chart; the median year is 17.0 mm (0.7 in).
Wettest day (Rx1day) at Ontario Ksrv by year
Year
Wettest day (Rx1day)
1903
0.5 mm (0.02 in)
1904
50.8 mm (2.0 in)
1905
61.0 mm (2.4 in)
1906
15.2 mm (0.6 in)
1907
10.7 mm (0.4 in)
1908
8.9 mm (0.35 in)
1945
16.0 mm (0.6 in)
1946
10.7 mm (0.4 in)
1947
19.1 mm (0.8 in)
1948
16.3 mm (0.6 in)
1949
9.7 mm (0.38 in)
1950
14.7 mm (0.6 in)
1951
19.3 mm (0.8 in)
1952
13.2 mm (0.5 in)
1953
22.6 mm (0.9 in)
1954
14.5 mm (0.6 in)
1955
17.5 mm (0.7 in)
1956
19.1 mm (0.8 in)
1957
21.8 mm (0.9 in)
1958
26.2 mm (1.0 in)
1959
40.4 mm (1.6 in)
1960
16.3 mm (0.6 in)
1961
15.0 mm (0.6 in)
1962
16.3 mm (0.6 in)
1963
18.5 mm (0.7 in)
1964
17.0 mm (0.7 in)
1965
14.7 mm (0.6 in)
1966
8.1 mm (0.32 in)
1967
15.5 mm (0.6 in)
1968
35.6 mm (1.4 in)
1969
20.3 mm (0.8 in)
1970
21.1 mm (0.8 in)
1971
17.8 mm (0.7 in)
1972
13.7 mm (0.5 in)
1973
15.5 mm (0.6 in)
1974
9.9 mm (0.39 in)
1975
18.5 mm (0.7 in)
1976
15.7 mm (0.6 in)
1977
27.4 mm (1.1 in)
1978
19.1 mm (0.8 in)
1979
30.0 mm (1.2 in)
1980
21.8 mm (0.9 in)
1981
25.1 mm (1.0 in)
1982
26.2 mm (1.0 in)
1983
26.7 mm (1.1 in)
1984
11.9 mm (0.5 in)
1985
14.2 mm (0.6 in)
1986
16.5 mm (0.6 in)
1987
17.0 mm (0.7 in)
1988
14.7 mm (0.6 in)
1989
16.5 mm (0.6 in)
1990
21.8 mm (0.9 in)
1991
20.3 mm (0.8 in)
1992
22.1 mm (0.9 in)
1993
34.3 mm (1.4 in)
1994
15.2 mm (0.6 in)
1995
20.3 mm (0.8 in)
1996
30.2 mm (1.2 in)
1997
20.8 mm (0.8 in)
1998
39.6 mm (1.6 in)
1999
15.2 mm (0.6 in)
2000
13.2 mm (0.5 in)
2001
16.0 mm (0.6 in)
2002
14.5 mm (0.6 in)
2003
12.7 mm (0.5 in)
2004
17.8 mm (0.7 in)
2005
28.4 mm (1.1 in)
2006
19.1 mm (0.8 in)
2007
14.5 mm (0.6 in)
2008
21.8 mm (0.9 in)
2009
12.7 mm (0.5 in)
2010
21.1 mm (0.8 in)
2011
6.3 mm (0.25 in)
Wettest five days (Rx5day)
The wettest five days of the year at Ontario Ksrv, 1903 to 2011. The record is 70.5 mm (2.8 in) in 2005, marked on the chart; the median year is 30.2 mm (1.2 in).
Wettest five days (Rx5day) at Ontario Ksrv by year
Year
Wettest five days (Rx5day)
1903
1.4 mm (0.06 in)
1904
66.1 mm (2.6 in)
1905
61.0 mm (2.4 in)
1906
22.9 mm (0.9 in)
1907
28.5 mm (1.1 in)
1908
12.7 mm (0.5 in)
1945
31.0 mm (1.2 in)
1946
20.6 mm (0.8 in)
1947
35.6 mm (1.4 in)
1948
18.9 mm (0.7 in)
1949
16.3 mm (0.6 in)
1950
23.3 mm (0.9 in)
1951
28.0 mm (1.1 in)
1952
17.5 mm (0.7 in)
1953
42.4 mm (1.7 in)
1954
25.7 mm (1.0 in)
1955
23.1 mm (0.9 in)
1956
43.5 mm (1.7 in)
1957
26.2 mm (1.0 in)
1958
37.6 mm (1.5 in)
1959
53.1 mm (2.1 in)
1960
31.2 mm (1.2 in)
1961
21.8 mm (0.9 in)
1962
46.8 mm (1.8 in)
1963
33.5 mm (1.3 in)
1964
32.3 mm (1.3 in)
1965
31.5 mm (1.2 in)
1966
21.6 mm (0.9 in)
1967
25.4 mm (1.0 in)
1968
56.4 mm (2.2 in)
1969
40.9 mm (1.6 in)
1970
36.9 mm (1.5 in)
1971
31.1 mm (1.2 in)
1972
21.3 mm (0.8 in)
1973
29.7 mm (1.2 in)
1974
17.9 mm (0.7 in)
1975
31.0 mm (1.2 in)
1976
39.6 mm (1.6 in)
1977
41.9 mm (1.6 in)
1978
25.2 mm (1.0 in)
1979
31.8 mm (1.3 in)
1980
41.6 mm (1.6 in)
1981
38.8 mm (1.5 in)
1982
50.6 mm (2.0 in)
1983
43.7 mm (1.7 in)
1984
31.0 mm (1.2 in)
1985
21.6 mm (0.9 in)
1986
22.6 mm (0.9 in)
1987
27.7 mm (1.1 in)
1988
28.9 mm (1.1 in)
1989
30.3 mm (1.2 in)
1990
30.2 mm (1.2 in)
1991
30.7 mm (1.2 in)
1992
25.4 mm (1.0 in)
1993
34.7 mm (1.4 in)
1994
23.6 mm (0.9 in)
1995
33.5 mm (1.3 in)
1996
55.1 mm (2.2 in)
1997
17.3 mm (0.7 in)
1998
67.6 mm (2.7 in)
1999
20.6 mm (0.8 in)
2000
33.3 mm (1.3 in)
2001
20.3 mm (0.8 in)
2002
26.0 mm (1.0 in)
2003
22.4 mm (0.9 in)
2004
26.7 mm (1.1 in)
2005
70.5 mm (2.8 in)
2006
44.8 mm (1.8 in)
2007
20.6 mm (0.8 in)
2008
31.8 mm (1.3 in)
2009
17.8 mm (0.7 in)
2010
27.2 mm (1.1 in)
2011
26.4 mm (1.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Ontario Ksrv, 1903 to 2011. The record is 153 days in 1999, marked on the chart; the median year is 54 days.
Longest dry spell (CDD) at Ontario Ksrv by year
Year
Longest dry spell (CDD)
1903
31 days
1904
54 days
1905
37 days
1906
24 days
1907
42 days
1908
28 days
1945
28 days
1946
56 days
1947
66 days
1948
48 days
1949
59 days
1950
60 days
1951
70 days
1952
66 days
1953
74 days
1954
65 days
1955
9 days
1956
39 days
1957
107 days
1958
34 days
1959
59 days
1960
45 days
1961
50 days
1962
54 days
1963
76 days
1964
44 days
1965
36 days
1966
63 days
1967
69 days
1968
77 days
1969
84 days
1970
66 days
1971
33 days
1972
61 days
1973
112 days
1974
90 days
1975
45 days
1976
56 days
1977
57 days
1978
71 days
1979
40 days
1980
70 days
1981
43 days
1982
38 days
1983
36 days
1984
38 days
1985
39 days
1986
75 days
1987
100 days
1988
82 days
1989
36 days
1990
62 days
1991
46 days
1992
72 days
1993
46 days
1994
84 days
1995
31 days
1996
34 days
1997
40 days
1998
36 days
1999
153 days
2000
63 days
2001
44 days
2002
53 days
2003
60 days
2004
27 days
2005
39 days
2006
47 days
2007
70 days
2008
58 days
2009
79 days
2010
115 days
2011
18 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
54 years with a frost
Across 54 years with a frost, the median last spring frost at Ontario Ksrv falls on 8 May and the median first autumn frost on 28 September, which leaves a median of 143 days between them.
Fitted over all years, the growing season changes by +1.7 days per decade at this station.
Frost dates and growing season at Ontario Ksrv
Measure
Median, all years
Earliest period
Recent period (1973 to 2010)
Recent against earliest
Fitted trend
Last spring frost
8 May
n/a
7 May
n/a
-0.5 days per decade
First autumn frost
28 September
n/a
2 October
n/a
+1.3 days per decade
Growing days
143 days
n/a
144 days
n/a
+1.7 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
55 years, 1907 to 2010
A day with at least 17.1 mm (0.7 in) of rain is expected about once in 2 years. A day with at least 43.2 mm (1.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Ontario Ksrv: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
17.1 mm (0.7 in)
5 years
22.9 mm (0.9 in)
10 years
27.1 mm (1.1 in)
25 years
33.1 mm (1.3 in)
50 years
38.0 mm (1.5 in)
100 years
43.2 mm (1.7 in)
Longer than the 55 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, 55 years of values from 1907 to 2010.
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: 40.4 mm (1.6 in) in 1959; 39.6 mm (1.6 in) in 1998; 35.6 mm (1.4 in) in 1968.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Ontario Ksrv, at 1956 and 1985. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1956 ran 0.6 C (1.1 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1985 ran 0.4 C (0.7 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Ontario Ksrv, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1956
+0.6
+1.1
likely
5
1985
-0.4
-0.7
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 Ontario Ksrv standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Ontario Ksrv 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.