Kingshuk Mondal / CC BY 4.0
Rancho Cucamonga, CA Weather on August 27
August 27th in Rancho Cucamonga, CA typically brings hot summer weather, with average highs around 95°F and lows near 64°F — a 31°F daily swing. Over 42 years of records, the warmest August 27th was in 1981 (90°F average), while the coldest was 1972 (66°F) — a 24°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 27th dates historically. The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
What to Expect on August 27
Planning for August 27th in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
August 27 Weather Records for Rancho Cucamonga
- •The all-time record high for August 27th in Rancho Cucamonga, CA is 111°F, set in 1981.
- •The coldest August 27th on record dropped to 51°F in 1973.
- •Temperatures have reached 90°F or higher on August 27th in 32 of the last 42 years.
- •Last year (1971), August 27th was 5°F warmer than the long-term average.
Frequently Asked Questions
What was the warmest August 27 ever in Rancho Cucamonga?
The warmest August 27 in Rancho Cucamonga, CA reached 111°F in 1981. That is 16°F above the long-term average high of 95°F.
What was the coldest August 27 ever in Rancho Cucamonga?
The coldest August 27 in Rancho Cucamonga, CA dropped to 51°F in 1973. That is 13°F below the long-term average low of 64°F.
What is the average temperature on August 27 in Rancho Cucamonga?
On August 27, Rancho Cucamonga averages a high of 95°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 27 in Rancho Cucamonga?
We have 42 years of weather records for August 27 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 27 Weather History in Rancho Cucamonga
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 98°F | 69°F | 0" | -- |
| 2024 | 93°F | 66°F | 0" | -- |
| 2023 | 102°F | 66°F | 0" | -- |
| 2022 | 91°F | 66°F | 0" | -- |
| 2021 | 104°F | 69°F | 0" | -- |
| 2020 | 103°F | 71°F | 0" | -- |
| 2019 | 96°F | 69°F | 0" | -- |
| 2018 | 88°F | 63°F | 0" | -- |
| 2017 | 99°F | 66°F | 0" | -- |
| 2016 | 84°F | 60°F | 0" | -- |
| 2015 | 103°F | 73°F | 0" | -- |
| 2014 | 97°F | 68°F | 0" | -- |
| 2013 | 97°F | 75°F | 0" | -- |
| 2012 | 100°F | 63°F | 0" | -- |
| 2011 | 107°F | 74°F | 0" | -- |
| 2010 | 94°F | 61°F | 0" | -- |
| 2009 | 108°F | 66°F | 0" | -- |
| 2008 | 93°F | 65°F | 0" | -- |
| 2007 | 95°F | 67°F | 0" | -- |
| 2006 | 97°F | 63°F | 0" | -- |
| 2005 | 101°F | 71°F | 0" | -- |
| 2004 | 89°F | 62°F | 0" | -- |
| 2003 | 95°F | 69°F | 0" | -- |
| 2002 | 89°F | 60°F | 0" | -- |
| 2001 | 97°F | 64°F | 0" | -- |
| 2000 | 84°F | 63°F | 0" | -- |
| 1999 | 99°F | 67°F | 0" | -- |
| 1998 | 98°F | 64°F | 0" | -- |
| 1984 | 105°F | 62°F | 0" | -- |
| 1983 | 101°F | 61°F | 0" | -- |
| 1982 | 94°F | 67°F | 0" | -- |
| 1981 | 111°F | 70°F | 0" | -- |
| 1980 | 93°F | 55°F | 0" | -- |
| 1979 | 93°F | 60°F | 0" | -- |
| 1978 | 88°F | 55°F | 0" | -- |
| 1977 | 83°F | 62°F | 0" | -- |
| 1976 | 94°F | 59°F | 0" | -- |
| 1975 | 88°F | 54°F | 0" | -- |
| 1974 | 91°F | 55°F | 0" | -- |
| 1973 | 80°F | 51°F | 0" | -- |
| 1972 | 76°F | 57°F | 0.04" | -- |
| 1971 | 100°F | 51°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.