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Ontario, CA Weather on October 11
October 11th in Ontario, CA typically brings warm fall weather, with average highs around 81°F and lows near 55°F — a 26°F daily swing. Over 41 years of records, the warmest October 11th was in 2015 (84°F average), while the coldest was 1975 (56°F) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 7% of October 11th dates historically. The last decade has been 1.7°F warmer on this date compared to 20-30 years ago.
What to Expect on October 11
Planning for October 11th in Ontario, CA? Stay hydrated and seek shade during peak afternoon hours.
October 11 Weather Records for Ontario
- •The all-time record high for October 11th in Ontario, CA is 99°F, set in 1971.
- •The coldest October 11th on record dropped to 42°F in 1973.
- •Temperatures have reached 90°F or higher on October 11th in 8 of the last 41 years.
- •Last year (1971), October 11th was 18°F warmer than the long-term average.
Frequently Asked Questions
What was the warmest October 11 ever in Ontario?
The warmest October 11 in Ontario, CA reached 99°F in 1971. That is 18°F above the long-term average high of 81°F.
What was the coldest October 11 ever in Ontario?
The coldest October 11 in Ontario, CA dropped to 42°F in 1973. That is 13°F below the long-term average low of 55°F.
What is the average temperature on October 11 in Ontario?
On October 11, Ontario averages a high of 81°F and a low of 55°F based on 41 years of NOAA weather observations from ONTARIO INTL AP.
How many years of weather data are available for October 11 in Ontario?
We have 41 years of weather records for October 11 in Ontario, CA, sourced from NOAA's Global Historical Climatology Network. Records include daily high and low temperatures, precipitation, and snowfall data going back to 2025.
October 11 Weather History in Ontario
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 85°F | 62°F | 0" | -- |
| 2024 | 93°F | 63°F | 0" | -- |
| 2023 | 76°F | 59°F | 0" | -- |
| 2022 | 80°F | 63°F | 0" | -- |
| 2021 | 72°F | 55°F | 0" | -- |
| 2020 | 83°F | 59°F | 0" | -- |
| 2019 | 85°F | 57°F | 0" | -- |
| 2018 | 75°F | 60°F | 0" | -- |
| 2017 | 83°F | 56°F | 0" | -- |
| 2016 | 76°F | 57°F | 0" | -- |
| 2015 | 98°F | 70°F | 0" | -- |
| 2014 | 89°F | 59°F | 0" | -- |
| 2013 | 77°F | 50°F | 0" | -- |
| 2012 | 68°F | 54°F | 0.16" | -- |
| 2011 | 87°F | 56°F | 0" | -- |
| 2010 | 91°F | 61°F | 0" | -- |
| 2009 | 70°F | 52°F | 0" | -- |
| 2008 | 69°F | 49°F | 0" | -- |
| 2007 | 77°F | 54°F | 0" | -- |
| 2006 | 81°F | 53°F | 0" | -- |
| 2005 | 80°F | 56°F | 0" | -- |
| 2004 | 80°F | 54°F | 0" | -- |
| 2003 | 90°F | 58°F | 0" | -- |
| 2002 | 74°F | 58°F | 0" | -- |
| 2001 | 84°F | 54°F | 0" | -- |
| 2000 | 63°F | 51°F | 0.08" | -- |
| 1999 | 94°F | 59°F | 0" | -- |
| 1998 | 83°F | 51°F | 0" | -- |
| 1983 | 89°F | 53°F | 0" | -- |
| 1982 | 84°F | 65°F | 0" | -- |
| 1981 | 71°F | 51°F | 0" | -- |
| 1980 | 92°F | 51°F | 0" | -- |
| 1979 | 78°F | 55°F | 0" | -- |
| 1978 | 93°F | 58°F | 0" | -- |
| 1977 | 89°F | 51°F | 0" | -- |
| 1976 | 85°F | 56°F | 0" | -- |
| 1975 | 67°F | 45°F | 0.11" | -- |
| 1974 | 70°F | 46°F | 0" | -- |
| 1973 | 77°F | 42°F | 0" | -- |
| 1972 | 79°F | 45°F | 0" | -- |
| 1971 | 99°F | 62°F | 0" | -- |
Based on 41 years of data from NOAA station: ONTARIO INTL AP
Monthly Climate Averages
Historical temperature and precipitation averages for Ontario, CA, based on 55+ years of weather data.
Temperatures in Fahrenheit. Precipitation and snowfall in inches.