44.014°N, 117.008°W · station ONOthr · 82 years of record
84°F
HOTTEST SEP 1 SINCE 2025
forecast high · Sep 1
7-Day Forecast
NWS NDFD forecast high temperature for Ontario.
This Day in History
Every year's high on each of the next 7 forecast dates at Ontario — toggle a day below. The forecast line shows where it lands; the ringed bar is the hottest on record.
Ranks
#62 / 79
warmest Sep 1 in 79 yrs of record
Warmest Sep 1 ever
104°F
set in 1967
Coolest Sep 1 ever
65°F
set in 1964
Forecast high 84°F — 62nd warmest Sep 1 of 79 years · record 104°F (1967) · warmest since 2025.
Ranks
#72 / 76
warmest Sep 2 in 76 yrs of record
Warmest Sep 2 ever
100°F
set in 1967
Coolest Sep 2 ever
58°F
set in 1964
Forecast high 77°F — 72nd warmest Sep 2 of 76 years · record 100°F (1967) · warmest since 2025.
Ranks
#79 / 79
warmest Sep 3 in 79 yrs of record
Warmest Sep 3 ever
100°F
set in 2022
Coolest Sep 3 ever
65°F
set in 2000
Forecast high 67°F — 79th warmest Sep 3 of 79 years · record 100°F (2022) · warmest since 2025.
Ranks
#77 / 77
warmest Sep 4 in 77 yrs of record
Warmest Sep 4 ever
99°F
set in 1960
Coolest Sep 4 ever
69°F
set in 2000
Forecast high 71°F — 77th warmest Sep 4 of 77 years · record 99°F (1960) · warmest since 2025.
Ranks
#70 / 78
warmest Sep 5 in 78 yrs of record
Warmest Sep 5 ever
101°F
set in 2019
Coolest Sep 5 ever
66°F
set in 2015
Forecast high 76°F — 70th warmest Sep 5 of 78 years · record 101°F (2019) · warmest since 2025.
Ranks
#67 / 77
warmest Sep 6 in 77 yrs of record
Warmest Sep 6 ever
101°F
set in 1966
Coolest Sep 6 ever
67°F
set in 2000
Forecast high 77°F — 67th warmest Sep 6 of 77 years · record 101°F (1966) · warmest since 2025.
Ranks
#67 / 79
warmest Sep 7 in 79 yrs of record
Warmest Sep 7 ever
102°F
set in 2022
Coolest Sep 7 ever
61°F
set in 1978
Forecast high 76°F — 67th warmest Sep 7 of 79 years · record 102°F (2022) · warmest since 2025.
The hottest and coldest ever recorded at Ontario in each calendar month, and for the whole 1945–2026 record — with the year each was set.
Month
Record High
Record Low
Jan
64°FJan 9, 1953
-25°FJan 27, 1957
Feb
69°FFeb 29, 2024
-24°FFeb 4, 1989
Mar
85°FMar 30, 1966
9°FMar 11, 1948
Apr
94°FApr 24, 1977
17°FApr 6, 1956
May
103°FMay 29, 1986
25°FMay 1, 1946
Jun
109°FJun 28, 2015
31°FJun 18, 1973
Jul
113°FJul 12, 1967
34°FJul 5, 1986
Aug
113°FAug 4, 1961
33°FAug 28, 1960
Sep
104°FSep 1, 1967
24°FSep 19, 1965
Oct
93°FOct 3, 1963
9°FOct 30, 2019
Nov
74°FNov 7, 2006
-6°FNov 25, 1993
Dec
66°FDec 22, 1955
-23°FDec 10, 1972
All-time
113°FAug 4, 1961
-25°FJan 27, 1957
2026 Records So Far
Records set or tied at Ontario so far this year — through Aug 30.
Record Highs in 2026
2 broke
plus 1 tied — daily record highs set this year
Record Lows in 2026
0 broke
plus 0 tied — daily record lows set this year
Record Warm Nights & Cold Days
Two more daily records, kept separate from the rankings: the warmest a night has ever stayed (record high minimum) and the coldest a day has ever gotten (record low maximum) — the flip side of the usual record high and low.
Warmest low ever
81°F
record high minimum — the night it never cooled · Jun 30, 2015
Coldest high ever
-1°F
record low maximum — the day it never warmed · Dec 22, 1990
Month
Warmest low
Coldest high
Jan
45°FJan 4, 1966
3°FJan 23, 1962
Feb
48°FFeb 9, 2015
1°FFeb 6, 1989
Mar
55°FMar 13, 2003
23°FMar 1, 1993
Apr
57°FApr 28, 1987
43°FApr 7, 2001
May
71°FMay 29, 2009
49°FMay 8, 1948
Jun
81°FJun 30, 2015
52°FJun 7, 1950
Jul
80°FJul 20, 2003
67°FJul 10, 1974
Aug
77°FAug 2, 1971
61°FAug 7, 2009
Sep
70°FSep 2, 1949
53°FSep 30, 1971
Oct
62°FOct 2, 2015
37°FOct 29, 2009
Nov
53°FNov 21, 1974
13°FNov 18, 2014
Dec
50°FDec 22, 1955
-1°FDec 22, 1990
All-time
81°FJun 30, 2015
-1°FDec 22, 1990
Hot Streaks
Current run
0 days
consecutive days with a high ≥ 90°F
Longest ever
74 days
record run, ended Sep 9 1967
So far in 2026
63 days
days with a high ≥ 90°F this year
Climate Normals
Normal high & low by month, from Ontario's own 1991–2020 record. Today's normal high: 87°F · forecast is -3° vs normal.
Ontario's observed daily high for the last six weeks — a white ring marks any day that broke or tied its daily record for that date.
2026 So Far
Every day this year against Ontario's own record — the record high, the normal, and the full span ever seen. A shareable look at where the year stands.