Historical Weather in Ontario, CA
See 55+ years of weather history for any date in Ontario going back to 1970.
Part of California weather history
Look Up a Specific Date
Today in Ontario Weather HistorySee records, averages, and 55+ years of data for today's date
→Monthly Climate Averages
Historical temperature and precipitation averages for Ontario, CA, based on 55+ years of weather data.
Warmest MonthAugustAvg High: 94°F / Low: 63°F
Coldest MonthDecemberAvg High: 67°F / Low: 41°F
Jan
67°/ 42°
💧 11.5"
Feb
68°/ 43°
💧 12.5"
Mar
71°/ 46°
💧 8.4"
Apr
75°/ 48°
💧 5.0"
May
79°/ 53°
💧 4.6"
Jun
86°/ 58°
💧 1.5"
Jul
93°/ 62°
💧 3.2"
Aug
94°/ 63°
💧 8.4"
Sep
91°/ 61°
💧 4.3"
Oct
82°/ 54°
💧 5.5"
Nov
74°/ 46°
💧 6.2"
Dec
67°/ 41°
💧 9.5"
Temperatures in Fahrenheit. Precipitation and snowfall in inches.
Ontario Temperature Records
- Record High: The hottest temperature ever recorded in Ontario, CA is 121°F, set on September 6, 2020.
- Record Low: The coldest temperature ever recorded in Ontario, CA is 20°F, set on January 14, 2007.
- Data Coverage: Based on 29 years of data from NOAA weather station: ONTARIO INTL AP.
All-Time Record High
121°F
September 6, 2020
All-Time Record Low
20°F
January 14, 2007
Monthly Temperature Records in Ontario
| Month | Record High | Record Low |
|---|---|---|
| January | 101°F(2003) | 20°F(2007) |
| February | 95°F(2016) | 23°F(2013) |
| March | 97°F(2011) | 28°F(2002) |
| April | 106°F(2004) | 30°F(2013) |
| May | 105°F(2003) | 37°F(2017) |
| June | 115°F(2016) | 42°F(1999) |
| July | 120°F(2018) | 47°F(2013) |
| August | 115°F(2017) | 48°F(2013) |
| September | 121°F(2020) | 39°F(2013) |
| October | 111°F(2020) | 33°F(2009) |
| November | 100°F(2010) | 27°F(2004) |
| December | 92°F(2021) | 21°F(2011) |
Ontario Snow RecordsSee the top 10 snowiest days ever recorded
→