Weather on October 21
Rancho Cucamonga, CA
55 Years of Data
About This Date
October 21st in Rancho Cucamonga, CA typically brings warm fall weather, with average highs around 80°F and lows near 54°F — a 26°F daily swing. Over 41 years of records, the warmest October 21st was in 2003 (82°F average), while the coldest was 1979 (56°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 5% of October 21st dates historically. The last decade has been 5.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.5°F warmer on this date compared to 20-30 years ago.
Planning for October 21st in Rancho Cucamonga, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 90° | 58° | 74° | — | — |
| 2024 | 89° | 57° | 73° | — | — |
| 2023 | 89° | 63° | 76° | — | — |
| 2022 | 83° | 61° | 72° | — | — |
| 2021 | 86° | 54° | 70° | — | — |
| 2020 | 79° | 62° | 70° | — | — |
| 2019 | 95° | 57° | 76° | — | — |
| 2018 | 83° | 58° | 70° | — | — |
| 2017 | 82° | 54° | 68° | — | — |
| 2016 | 94° | 56° | 75° | — | — |
| 2015 | 85° | 57° | 71° | — | — |
| 2014 | 81° | 58° | 69° | — | — |
| 2013 | 84° | 52° | 68° | — | — |
| 2012 | 73° | 62° | 68° | — | — |
| 2011 | 77° | 58° | 67° | — | — |
| 2010 | 62° | 58° | 60° | 0.08" | — |
| 2009 | 84° | 53° | 69° | — | — |
| 2008 | 92° | 53° | 72° | — | — |
| 2007 | 83° | 54° | 68° | — | — |
| 2006 | 93° | 53° | 73° | — | — |
| 2005 | 76° | 57° | 66° | — | — |
| 2004 | 66° | 50° | 58° | 0.03" | — |
| 2003warmest | 101° | 63° | 82° | — | — |
| 2002 | 67° | 55° | 61° | — | — |
| 2001 | 73° | 57° | 65° | — | — |
| 2000 | 68° | 58° | 63° | — | — |
| 1999 | 94° | 54° | 74° | — | — |
| 1998 | 80° | 51° | 66° | — | — |
| 1983 | 86° | 48° | 67° | — | — |
| 1982 | 81° | 50° | 65° | — | — |
| 1981 | 84° | 47° | 65° | — | — |
| 1980 | 87° | 50° | 69° | — | — |
| 1979coldest | 67° | 45° | 56° | — | — |
| 1978 | 73° | 58° | 65° | — | — |
| 1977 | 69° | 53° | 61° | — | — |
| 1976 | 75° | 59° | 67° | — | — |
| 1975 | 67° | 48° | 57° | — | — |
| 1974 | 67° | 55° | 61° | — | — |
| 1973 | 71° | 47° | 59° | — | — |
| 1972 | 68° | 46° | 57° | — | — |
| 1971 | 79° | 41° | 60° | — | — |
Rancho Cucamonga, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Rancho Cucamonga, CA Monthly Precipitation
Average rainfall per month, in inches.
Rancho Cucamonga, CA Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Rancho Cucamonga, CA
Rancho Cucamonga, CA has no months that meet our "pleasant" threshold — every season has tradeoffs.