Weather on May 21
Simi Valley, CA
55 Years of Data
About This Date
May 21st in Simi Valley, CA typically brings pleasant spring weather, with average highs around 79°F and lows near 57°F. Over 31 years of records, the warmest May 21st was in 2006 (143°F average), while the coldest was 2002 (55°F) — a 88°F range across recorded history. This date has historically been dry, with little recorded precipitation. 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 May 21st in Simi Valley, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 90° | 58° | 74° | — | — |
| 2025 | 94° | 66° | 80° | — | — |
| 2024 | 74° | 49° | 61° | — | — |
| 2023 | 84° | 55° | 70° | — | — |
| 2022 | 73° | 51° | 62° | — | — |
| 2021 | 64° | 46° | 55° | — | — |
| 2020 | 87° | 59° | 73° | — | — |
| 2019 | 66° | 48° | 57° | — | — |
| 2018 | 63° | 53° | 58° | — | — |
| 2017 | 95° | 71° | 83° | — | — |
| 2016 | 63° | 48° | 55° | — | — |
| 2015 | 62° | 49° | 55° | — | — |
| 2014 | 69° | 50° | 60° | — | — |
| 2013 | 90° | 57° | 73° | — | — |
| 2012 | 81° | 54° | 67° | — | — |
| 2011 | 70° | 50° | 60° | — | — |
| 2010 | 70° | 51° | 60° | — | — |
| 2009 | 77° | 54° | 65° | — | — |
| 2008 | 73° | 55° | 64° | — | — |
| 2007 | 61° | 55° | 58° | — | — |
| 2006warmest | 145° | 140° | 143° | — | — |
| 2005 | 88° | 63° | 75° | — | — |
| 2004 | 66° | 50° | 58° | — | — |
| 2003 | 91° | 63° | 77° | — | — |
| 2002coldest | 64° | 46° | 55° | — | — |
| 2001 | 83° | 55° | 69° | — | — |
| 2000 | 103° | 62° | 82° | — | — |
| 1999 | 67° | 48° | 57° | — | — |
| 1998 | 67° | 50° | 58° | — | — |
| 1997 | 79° | 55° | 67° | — | — |
| 1996 | 77° | 54° | 65° | — | — |
Simi Valley, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Simi Valley, 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 Simi Valley, CA
Most pleasant months in Simi Valley, CA: January, March, April, May, June, October, November.