Weather on September 5
Simi Valley, CA
55 Years of Data
Avg High
91°F
Avg Low
66°F
Warmest
2020
102°F avg
Coldest
2023
66°F avg
About This Date
September 5th in Simi Valley, CA typically brings hot fall weather, with average highs around 91°F and lows near 66°F — a 25°F daily swing. Over 30 years of records, the warmest September 5th was in 2020 (102°F average), while the coldest was 2023 (66°F) — a 36°F range across recorded history. This date has historically been dry, with little recorded precipitation. The last decade has been 6.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.9°F warmer on this date compared to 20-30 years ago.
Planning for September 5th in Simi Valley, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
3.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 97° | 64° | 80° | — | — |
| 2024 | 109° | 89° | 99° | — | — |
| 2023coldest | 74° | 58° | 66° | — | — |
| 2022 | 109° | 76° | 92° | — | — |
| 2021 | 107° | 76° | 91° | — | — |
| 2020warmest | 116° | 87° | 102° | — | — |
| 2019 | 102° | 75° | 89° | — | — |
| 2018 | 85° | 59° | 72° | — | — |
| 2017 | 89° | 65° | 77° | — | — |
| 2016 | 78° | 56° | 67° | — | — |
| 2015 | 85° | 58° | 71° | — | — |
| 2014 | 95° | 60° | 78° | — | — |
| 2013 | 102° | 77° | 90° | — | — |
| 2012 | 77° | 66° | 72° | — | — |
| 2011 | 93° | 59° | 76° | — | — |
| 2010 | 83° | 58° | 70° | — | — |
| 2009 | 84° | 64° | 74° | — | — |
| 2008 | 88° | 64° | 76° | — | — |
| 2007 | 84° | 57° | 71° | — | — |
| 2006 | 91° | 70° | 80° | — | — |
| 2005 | 84° | 59° | 72° | — | — |
| 2004 | 97° | 70° | 83° | — | — |
| 2003 | 93° | 66° | 80° | — | — |
| 2002 | 83° | 69° | 76° | — | — |
| 2001 | 92° | 63° | 77° | — | — |
| 2000 | 86° | 63° | 74° | — | — |
| 1999 | 89° | 56° | 72° | — | — |
| 1998 | 79° | 66° | 72° | — | — |
| 1997 | 97° | 71° | 84° | — | — |
| 1996 | 93° | 59° | 76° | — | — |
30 years of data from SIMI VALLEY CALIFORNIA