Weather on August 17
Simi Valley, CA
55 Years of Data
Avg High
89°F
Avg Low
64°F
Warmest
2020
88°F avg
Coldest
2009
64°F avg
About This Date
August 17th in Simi Valley, CA typically brings warm summer weather, with average highs around 89°F and lows near 64°F — a 25°F daily swing. Over 30 years of records, the warmest August 17th was in 2020 (88°F average), while the coldest was 2009 (64°F) — a 24°F range across recorded history. This date has historically been dry, with little recorded precipitation. The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.
Planning for August 17th in Simi Valley, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 85° | 59° | 72° | — | — |
| 2024 | 88° | 62° | 75° | — | — |
| 2023 | 97° | 69° | 83° | — | — |
| 2022 | 101° | 70° | 85° | — | — |
| 2021 | 91° | 62° | 77° | — | — |
| 2020warmest | 102° | 73° | 88° | — | — |
| 2019 | 87° | 57° | 72° | — | — |
| 2018 | 91° | 65° | 78° | — | — |
| 2017 | 88° | 59° | 73° | — | — |
| 2016 | 99° | 70° | 84° | — | — |
| 2015 | 89° | 65° | 77° | — | — |
| 2014 | 95° | 70° | 82° | — | — |
| 2013 | 99° | 67° | 83° | — | — |
| 2012 | 91° | 70° | 80° | — | — |
| 2011 | 84° | 57° | 71° | — | — |
| 2010 | 93° | 64° | 79° | — | — |
| 2009coldest | 76° | 52° | 64° | — | — |
| 2008 | 81° | 59° | 70° | — | — |
| 2007 | 86° | 68° | 77° | — | — |
| 2006 | 79° | 55° | 67° | — | — |
| 2005 | 77° | 55° | 66° | — | — |
| 2004 | 79° | 59° | 69° | — | — |
| 2003 | 90° | 66° | 78° | — | — |
| 2002 | 73° | 59° | 66° | — | — |
| 2001 | 103° | 71° | 87° | — | — |
| 2000 | 96° | 70° | 83° | — | — |
| 1999 | 93° | 70° | 81° | — | — |
| 1998 | 86° | 60° | 73° | — | — |
| 1997 | 85° | 59° | 72° | — | — |
| 1996 | 93° | 63° | 78° | — | — |
30 years of data from SIMI VALLEY CALIFORNIA