Weather on September 1
Rancho Cucamonga, CA
55 Years of Data
Avg High
94°F
Avg Low
63°F
Warmest
2017
95°F avg
Coldest
1973
64°F avg
About This Date
September 1st in Rancho Cucamonga, CA typically brings hot fall weather, with average highs around 94°F and lows near 63°F — a 31°F daily swing. Over 41 years of records, the warmest September 1st was in 2017 (95°F average), while the coldest was 1973 (64°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 2% of September 1st dates historically. The last decade has been 3.1°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.1°F warmer on this date compared to 20-30 years ago.
Planning for September 1st in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
2.2°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 98° | 71° | 85° | — | — |
| 2024 | 96° | 66° | 81° | — | — |
| 2023 | 90° | 66° | 78° | 0.33" | — |
| 2022 | 107° | 78° | 93° | — | — |
| 2021 | 81° | 66° | 73° | — | — |
| 2020 | 89° | 61° | 75° | — | — |
| 2019 | 97° | 68° | 82° | — | — |
| 2018 | 86° | 63° | 74° | — | — |
| 2017warmest | 114° | 75° | 95° | — | — |
| 2016 | 94° | 65° | 79° | — | — |
| 2015 | 88° | 66° | 77° | — | — |
| 2014 | 96° | 65° | 80° | — | — |
| 2013 | 96° | 73° | 85° | — | — |
| 2012 | 95° | 64° | 80° | — | — |
| 2011 | 90° | 57° | 73° | — | — |
| 2010 | 98° | 64° | 81° | — | — |
| 2009 | 101° | 76° | 88° | — | — |
| 2008 | 91° | 65° | 78° | — | — |
| 2007 | 109° | 78° | 94° | — | — |
| 2006 | 102° | 66° | 84° | — | — |
| 2005 | 90° | 58° | 74° | — | — |
| 2004 | 103° | 64° | 83° | — | — |
| 2003 | 93° | 64° | 79° | — | — |
| 2002 | 110° | 72° | 91° | — | — |
| 2001 | 93° | 63° | 78° | — | — |
| 2000 | 76° | 59° | 67° | — | — |
| 1999 | 79° | 58° | 68° | — | — |
| 1998 | 105° | 69° | 87° | — | — |
| 1983 | 94° | 63° | 78° | — | — |
| 1982 | 105° | 62° | 84° | — | — |
| 1981 | 92° | 57° | 74° | — | — |
| 1980 | 85° | 59° | 72° | — | — |
| 1979 | 87° | 53° | 70° | — | — |
| 1978 | 92° | 58° | 75° | — | — |
| 1977 | 84° | 52° | 68° | — | — |
| 1976 | 92° | 58° | 75° | — | — |
| 1975 | 88° | 51° | 69° | — | — |
| 1974 | 96° | 61° | 78° | — | — |
| 1973coldest | 80° | 49° | 64° | — | — |
| 1972 | 90° | 55° | 72° | — | — |
| 1971 | 87° | 50° | 69° | — | — |
41 years of data from ONTARIO INTL AP