Weather on May 31
Simi Valley, CA
55 Years of Data
Avg High
80°F
Avg Low
54°F
Warmest
2025
80°F avg
Coldest
2008
57°F avg
About This Date
May 31st in Simi Valley, CA typically brings warm spring weather, with average highs around 80°F and lows near 54°F — a 26°F daily swing. Over 30 years of records, the warmest May 31st was in 2025 (80°F average), while the coldest was 2008 (57°F) — a 23°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 31st in Simi Valley, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 100° | 61° | 80° | — | — |
| 2024 | 80° | 52° | 66° | — | — |
| 2023 | 66° | 51° | 59° | — | — |
| 2022 | 83° | 55° | 69° | — | — |
| 2021 | 85° | 53° | 69° | — | — |
| 2020 | 84° | 51° | 68° | — | — |
| 2019 | 80° | 52° | 66° | — | — |
| 2018 | 71° | 55° | 63° | — | — |
| 2017 | 77° | 54° | 65° | — | — |
| 2016 | 83° | 53° | 68° | — | — |
| 2015 | 82° | 55° | 69° | — | — |
| 2014 | 87° | 58° | 72° | — | — |
| 2013 | 82° | 58° | 70° | — | — |
| 2012 | 81° | 54° | 67° | — | — |
| 2011 | 72° | 46° | 59° | — | — |
| 2010 | 78° | 55° | 67° | — | — |
| 2009 | 71° | 56° | 63° | — | — |
| 2008coldest | 68° | 46° | 57° | — | — |
| 2007 | 68° | 48° | 58° | — | — |
| 2006 | 82° | 59° | 71° | — | — |
| 2005 | 73° | 54° | 63° | — | — |
| 2004 | 82° | 61° | 71° | — | — |
| 2003 | 75° | 52° | 63° | — | — |
| 2002 | 84° | 55° | 70° | — | — |
| 2001 | 95° | 57° | 76° | — | — |
| 2000 | 81° | 56° | 68° | — | — |
| 1999 | 77° | 48° | 63° | — | — |
| 1998 | 79° | 51° | 65° | — | — |
| 1997 | 88° | 60° | 74° | — | — |
| 1996 | 83° | 52° | 67° | — | — |
30 years of data from SIMI VALLEY CALIFORNIA