Weather on September 30
Rancho Cucamonga, CA
55 Years of Data
Avg High
87°F
Avg Low
59°F
Warmest
2020
89°F avg
Coldest
1983
58°F avg
About This Date
September 30th in Rancho Cucamonga, CA typically brings warm fall weather, with average highs around 87°F and lows near 59°F — a 28°F daily swing. Over 41 years of records, the warmest September 30th was in 2020 (89°F average), while the coldest was 1983 (58°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 7% of September 30th dates historically, with the wettest September 30th recording 1.57" of rain. The last decade has been 2.2°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.2°F warmer on this date compared to 20-30 years ago.
Planning for September 30th in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 80° | 63° | 71° | — | — |
| 2024 | 98° | 61° | 79° | — | — |
| 2023 | 69° | 59° | 64° | — | — |
| 2022 | 86° | 63° | 74° | — | — |
| 2021 | 96° | 56° | 76° | — | — |
| 2020warmest | 108° | 70° | 89° | — | — |
| 2019 | 76° | 52° | 64° | — | — |
| 2018 | 93° | 61° | 77° | — | — |
| 2017 | 87° | 59° | 73° | — | — |
| 2016 | 94° | 69° | 81° | — | — |
| 2015 | 95° | 64° | 80° | — | — |
| 2014 | 90° | 62° | 76° | — | — |
| 2013 | 89° | 57° | 73° | — | — |
| 2012 | 103° | 66° | 84° | — | — |
| 2011 | 90° | 60° | 75° | — | — |
| 2010 | 94° | 68° | 81° | — | — |
| 2009 | 83° | 59° | 71° | — | — |
| 2008 | 102° | 68° | 85° | — | — |
| 2007 | 92° | 53° | 72° | — | — |
| 2006 | 85° | 60° | 72° | — | — |
| 2005 | 98° | 65° | 81° | — | — |
| 2004 | 71° | 58° | 64° | — | — |
| 2003 | 89° | 61° | 75° | — | — |
| 2002 | 68° | 54° | 61° | — | — |
| 2001 | 106° | 65° | 85° | — | — |
| 2000 | 80° | 57° | 69° | — | — |
| 1999 | 102° | 62° | 82° | — | — |
| 1998 | 74° | 54° | 64° | — | — |
| 1983coldest | 53° | 62° | 58° | 1.57" | — |
| 1982 | 75° | 46° | 61° | — | — |
| 1981 | 81° | 56° | 68° | 0.51" | — |
| 1980 | 108° | 59° | 83° | — | — |
| 1979 | 79° | 53° | 66° | — | — |
| 1978 | 91° | 62° | 77° | — | — |
| 1977 | 80° | 54° | 67° | — | — |
| 1976 | 78° | 58° | 68° | 0.33" | — |
| 1975 | 79° | 54° | 66° | — | — |
| 1974 | 93° | 61° | 77° | — | — |
| 1973 | 85° | 52° | 68° | — | — |
| 1972 | 95° | 60° | 78° | — | — |
| 1971 | 76° | 45° | 60° | — | — |
41 years of data from ONTARIO INTL AP