Weather on September 5
Ontario, CA
55 Years of Data
Avg High
94°F
Avg Low
65°F
Warmest
2020
96°F avg
Coldest
1973
66°F avg
About This Date
September 5th in Ontario, CA typically brings hot fall weather, with average highs around 94°F and lows near 65°F — a 29°F daily swing. Over 41 years of records, the warmest September 5th was in 2020 (96°F average), while the coldest was 1973 (66°F) — a 30°F range across recorded history. Rain or other precipitation has occurred on about 5% of September 5th dates historically, with the wettest September 5th recording 1.27" of rain. The last decade has been 7.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 7.0°F warmer on this date compared to 20-30 years ago.
Planning for September 5th in Ontario, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 96° | 67° | 81° | — | — |
| 2024 | 113° | 78° | 96° | — | — |
| 2023 | 79° | 63° | 71° | — | — |
| 2022 | 107° | 77° | 92° | — | — |
| 2021 | 108° | 71° | 89° | — | — |
| 2020warmest | 118° | 73° | 96° | — | — |
| 2019 | 100° | 76° | 88° | — | — |
| 2018 | 88° | 64° | 76° | — | — |
| 2017 | 92° | 68° | 80° | — | — |
| 2016 | 80° | 62° | 71° | — | — |
| 2015 | 89° | 59° | 74° | — | — |
| 2014 | 97° | 62° | 79° | — | — |
| 2013 | 104° | 77° | 91° | — | — |
| 2012 | 90° | 73° | 81° | — | — |
| 2011 | 95° | 67° | 81° | 0.05" | — |
| 2010 | 94° | 61° | 77° | — | — |
| 2009 | 97° | 68° | 82° | — | — |
| 2008 | 99° | 69° | 84° | — | — |
| 2007 | 95° | 64° | 80° | — | — |
| 2006 | 104° | 76° | 90° | — | — |
| 2005 | 93° | 57° | 75° | — | — |
| 2004 | 101° | 62° | 81° | — | — |
| 2003 | 101° | 74° | 87° | — | — |
| 2002 | 83° | 69° | 76° | — | — |
| 2001 | 92° | 64° | 78° | — | — |
| 2000 | 89° | 59° | 74° | — | — |
| 1999 | 81° | 57° | 69° | — | — |
| 1998 | 82° | 69° | 76° | — | — |
| 1983 | 93° | 57° | 75° | — | — |
| 1982 | 104° | 62° | 83° | — | — |
| 1981 | 87° | 66° | 77° | — | — |
| 1980 | 92° | 60° | 76° | — | — |
| 1979 | 94° | 58° | 76° | — | — |
| 1978 | 88° | 65° | 76° | 1.27" | — |
| 1977 | 100° | 64° | 82° | — | — |
| 1976 | 87° | 62° | 75° | — | — |
| 1975 | 95° | 63° | 79° | — | — |
| 1974 | 94° | 63° | 78° | — | — |
| 1973coldest | 79° | 54° | 66° | — | — |
| 1972 | 91° | 65° | 78° | — | — |
| 1971 | 94° | 54° | 74° | — | — |
41 years of data from ONTARIO INTL AP