Weather on September 15
Rancho Cucamonga, CA
55 Years of Data
About This Date
September 15th in Rancho Cucamonga, CA typically brings warm fall weather, with average highs around 88°F and lows near 61°F — a 27°F daily swing. Over 41 years of records, the warmest September 15th was in 2014 (93°F average), while the coldest was 1977 (62°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 2% of September 15th dates historically, with the wettest September 15th recording 3.18" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for September 15th in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 95° | 62° | 79° | — | — |
| 2024 | 76° | 63° | 69° | — | — |
| 2023 | 80° | 63° | 71° | — | — |
| 2022 | 84° | 65° | 74° | — | — |
| 2021 | 92° | 61° | 76° | — | — |
| 2020 | 98° | 67° | 82° | — | — |
| 2019 | 97° | 67° | 82° | — | — |
| 2018 | 94° | 63° | 78° | — | — |
| 2017 | 77° | 63° | 70° | — | — |
| 2016 | 86° | 57° | 72° | — | — |
| 2015 | 79° | 67° | 73° | 3.18" | — |
| 2014warmest | 107° | 78° | 93° | — | — |
| 2013 | 101° | 67° | 84° | — | — |
| 2012 | 104° | 71° | 88° | — | — |
| 2011 | 85° | 61° | 73° | — | — |
| 2010 | 89° | 60° | 75° | — | — |
| 2009 | 84° | 60° | 72° | — | — |
| 2008 | 101° | 62° | 81° | — | — |
| 2007 | 89° | 58° | 73° | — | — |
| 2006 | 75° | 58° | 66° | — | — |
| 2005 | 80° | 56° | 68° | — | — |
| 2004 | 84° | 62° | 73° | — | — |
| 2003 | 92° | 62° | 77° | — | — |
| 2002 | 97° | 62° | 79° | — | — |
| 2001 | 92° | 60° | 76° | — | — |
| 2000 | 98° | 66° | 82° | — | — |
| 1999 | 82° | 56° | 69° | — | — |
| 1998 | 88° | 60° | 74° | — | — |
| 1983 | 94° | 62° | 78° | — | — |
| 1982 | 74° | 61° | 67° | — | — |
| 1981 | 94° | 60° | 77° | — | — |
| 1980 | 81° | 48° | 64° | — | — |
| 1979 | 103° | 67° | 85° | — | — |
| 1978 | 77° | 50° | 64° | — | — |
| 1977coldest | 75° | 49° | 62° | — | — |
| 1976 | 73° | 60° | 67° | — | — |
| 1975 | 92° | 58° | 75° | — | — |
| 1974 | 86° | 50° | 68° | — | — |
| 1973 | 78° | 51° | 65° | — | — |
| 1972 | 84° | 49° | 66° | — | — |
| 1971 | 92° | 60° | 76° | — | — |