Kingshuk Mondal / CC BY 4.0
Rancho Cucamonga, CA Weather on August 25
August 25th in Rancho Cucamonga, CA typically brings hot summer weather, with average highs around 93°F and lows near 64°F — a 29°F daily swing. Over 42 years of records, the warmest August 25th was in 2010 (91°F average), while the coldest was 1973 (66°F) — a 25°F range across recorded history. This date has historically been dry, with little recorded precipitation. The last decade has been 1.0°F cooler on this date compared to 20-30 years ago.
What to Expect on August 25
Planning for August 25th in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
August 25 Weather Records for Rancho Cucamonga
- •The all-time record high for August 25th in Rancho Cucamonga, CA is 108°F, set in 2010.
- •The coldest August 25th on record dropped to 48°F in 1978.
- •Temperatures have reached 90°F or higher on August 25th in 32 of the last 42 years.
Frequently Asked Questions
What was the warmest August 25 ever in Rancho Cucamonga?
The warmest August 25 in Rancho Cucamonga, CA reached 108°F in 2010. That is 15°F above the long-term average high of 93°F.
What was the coldest August 25 ever in Rancho Cucamonga?
The coldest August 25 in Rancho Cucamonga, CA dropped to 48°F in 1978. That is 16°F below the long-term average low of 64°F.
What is the average temperature on August 25 in Rancho Cucamonga?
On August 25, Rancho Cucamonga averages a high of 93°F and a low of 64°F based on 42 years of NOAA weather observations from ONTARIO INTL AP.
How many years of weather data are available for August 25 in Rancho Cucamonga?
We have 42 years of weather records for August 25 in Rancho Cucamonga, CA, sourced from NOAA's Global Historical Climatology Network. Records include daily high and low temperatures, precipitation, and snowfall data going back to 2025.
August 25 Weather History in Rancho Cucamonga
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 98°F | 70°F | 0" | -- |
| 2024 | 88°F | 61°F | 0" | -- |
| 2023 | 94°F | 63°F | 0" | -- |
| 2022 | 95°F | 70°F | 0" | -- |
| 2021 | 100°F | 67°F | 0" | -- |
| 2020 | 99°F | 70°F | 0" | -- |
| 2019 | 98°F | 67°F | 0" | -- |
| 2018 | 89°F | 64°F | 0" | -- |
| 2017 | 88°F | 63°F | 0" | -- |
| 2016 | 90°F | 63°F | 0" | -- |
| 2015 | 93°F | 72°F | 0" | -- |
| 2014 | 88°F | 65°F | 0" | -- |
| 2013 | 97°F | 67°F | 0" | -- |
| 2012 | 87°F | 64°F | 0" | -- |
| 2011 | 100°F | 67°F | 0" | -- |
| 2010 | 108°F | 74°F | 0" | -- |
| 2009 | 99°F | 67°F | 0" | -- |
| 2008 | 100°F | 71°F | 0" | -- |
| 2007 | 91°F | 64°F | 0" | -- |
| 2006 | 92°F | 64°F | 0" | -- |
| 2005 | 100°F | 68°F | 0" | -- |
| 2004 | 87°F | 60°F | 0" | -- |
| 2003 | 96°F | 69°F | 0" | -- |
| 2002 | 94°F | 61°F | 0" | -- |
| 2001 | 97°F | 64°F | 0" | -- |
| 2000 | 92°F | 69°F | 0" | -- |
| 1999 | 105°F | 68°F | 0" | -- |
| 1998 | 93°F | 65°F | 0" | -- |
| 1984 | 94°F | 58°F | 0" | -- |
| 1983 | 92°F | 57°F | 0" | -- |
| 1982 | 94°F | 66°F | 0" | -- |
| 1981 | 107°F | 68°F | 0" | -- |
| 1980 | 92°F | 60°F | 0" | -- |
| 1979 | 92°F | 63°F | 0" | -- |
| 1978 | 84°F | 48°F | 0" | -- |
| 1977 | 84°F | 58°F | 0" | -- |
| 1976 | 92°F | 58°F | 0" | -- |
| 1975 | 91°F | 55°F | 0" | -- |
| 1974 | 94°F | 56°F | 0" | -- |
| 1973 | 80°F | 51°F | 0" | -- |
| 1972 | 80°F | 62°F | 0" | -- |
| 1971 | 92°F | 55°F | 0" | -- |
Based on 42 years of data from NOAA station: ONTARIO INTL AP
Monthly Climate Averages
Historical temperature and precipitation averages for Rancho Cucamonga, CA, based on 55+ years of weather data.
Temperatures in Fahrenheit. Precipitation and snowfall in inches.