Weather on August 17
Rancho Cucamonga, CA
55 Years of Data
Avg High
92°F
Avg Low
64°F
Warmest
2012
89°F avg
Coldest
1975
64°F avg
About This Date
August 17th in Rancho Cucamonga, CA typically brings hot summer weather, with average highs around 92°F and lows near 64°F — a 28°F daily swing. Over 42 years of records, the warmest August 17th was in 2012 (89°F average), while the coldest was 1975 (64°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 17th dates historically, with the wettest August 17th recording 4.88" of rain. The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
Planning for August 17th in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
2.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 90° | 63° | 76° | — | — |
| 2024 | 91° | 67° | 79° | — | — |
| 2023 | 102° | 69° | 86° | — | — |
| 2022 | 98° | 70° | 84° | — | — |
| 2021 | 92° | 70° | 81° | — | — |
| 2020 | 101° | 76° | 88° | — | — |
| 2019 | 88° | 62° | 75° | — | — |
| 2018 | 95° | 69° | 82° | — | — |
| 2017 | 89° | 62° | 76° | — | — |
| 2016 | 101° | 67° | 84° | — | — |
| 2015 | 94° | 68° | 81° | — | — |
| 2014 | 98° | 67° | 82° | — | — |
| 2013 | 98° | 67° | 82° | — | — |
| 2012warmest | 101° | 78° | 89° | — | — |
| 2011 | 96° | 64° | 80° | — | — |
| 2010 | 99° | 68° | 83° | — | — |
| 2009 | 88° | 58° | 73° | — | — |
| 2008 | 92° | 63° | 77° | — | — |
| 2007 | 99° | 73° | 86° | — | — |
| 2006 | 92° | 59° | 75° | — | — |
| 2005 | 86° | 60° | 73° | — | — |
| 2004 | 91° | 62° | 77° | — | — |
| 2003 | 100° | 66° | 83° | — | — |
| 2002 | 84° | 62° | 73° | — | — |
| 2001 | 100° | 65° | 82° | — | — |
| 2000 | 96° | 71° | 84° | — | — |
| 1999 | 98° | 64° | 81° | — | — |
| 1998 | 85° | 64° | 74° | — | — |
| 1984 | 105° | 66° | 86° | — | — |
| 1983 | 91° | 71° | 81° | — | — |
| 1982 | 92° | 58° | 75° | — | — |
| 1981 | 93° | 63° | 78° | — | — |
| 1980 | 84° | 61° | 72° | — | — |
| 1979 | 86° | 58° | 72° | — | — |
| 1978 | 85° | 51° | 68° | — | — |
| 1977 | 76° | 66° | 71° | 4.88" | — |
| 1976 | 80° | 53° | 67° | — | — |
| 1975coldest | 82° | 47° | 64° | — | — |
| 1974 | 91° | 52° | 71° | — | — |
| 1973 | 92° | 63° | 77° | — | — |
| 1972 | 86° | 56° | 71° | — | — |
| 1971 | 92° | 60° | 76° | — | — |
42 years of data from ONTARIO INTL AP