Kingshuk Mondal / CC BY 4.0
Simi Valley, CA Weather on August 25
August 25th in Simi Valley, CA typically brings hot summer weather, with average highs around 90°F and lows near 63°F — a 27°F daily swing. Over 30 years of records, the warmest August 25th was in 1999 (92°F average), while the coldest was 2012 (66°F) — a 26°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.
What to Expect on August 25
Planning for August 25th in Simi Valley, CA? Stay hydrated and seek shade during peak afternoon hours.
August 25 Weather Records for Simi Valley
- •The all-time record high for August 25th in Simi Valley, CA is 104°F, set in 1999.
- •The coldest August 25th on record dropped to 55°F in 2005.
- •Temperatures have reached 90°F or higher on August 25th in 18 of the last 30 years.
- •Last year (1996), August 25th was 8°F warmer than the long-term average.
Frequently Asked Questions
What was the warmest August 25 ever in Simi Valley?
The warmest August 25 in Simi Valley, CA reached 104°F in 1999. That is 14°F above the long-term average high of 90°F.
What was the coldest August 25 ever in Simi Valley?
The coldest August 25 in Simi Valley, CA dropped to 55°F in 2005. That is 8°F below the long-term average low of 63°F.
What is the average temperature on August 25 in Simi Valley?
On August 25, Simi Valley averages a high of 90°F and a low of 63°F based on 30 years of NOAA weather observations from SIMI VALLEY CALIFORNIA.
How many years of weather data are available for August 25 in Simi Valley?
We have 30 years of weather records for August 25 in Simi Valley, CA, sourced from NOAA's Global Historical Climatology Network. Records include daily high and low temperatures, precipitation, and snowfall data going back to 2025.
August 25 Weather History in Simi Valley
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 99°F | 69°F | -- | -- |
| 2024 | 86°F | 59°F | -- | -- |
| 2023 | 90°F | 63°F | -- | -- |
| 2022 | 97°F | 67°F | -- | -- |
| 2021 | 96°F | 65°F | -- | -- |
| 2020 | 96°F | 69°F | -- | -- |
| 2019 | 99°F | 68°F | -- | -- |
| 2018 | 88°F | 60°F | -- | -- |
| 2017 | 91°F | 59°F | -- | -- |
| 2016 | 86°F | 57°F | -- | -- |
| 2015 | 84°F | 67°F | -- | -- |
| 2014 | 83°F | 60°F | -- | -- |
| 2013 | 97°F | 68°F | -- | -- |
| 2012 | 75°F | 57°F | -- | -- |
| 2011 | 90°F | 63°F | -- | -- |
| 2010 | 93°F | 66°F | -- | -- |
| 2009 | 91°F | 61°F | -- | -- |
| 2008 | 86°F | 64°F | -- | -- |
| 2007 | 79°F | 59°F | -- | -- |
| 2006 | 79°F | 57°F | -- | -- |
| 2005 | 93°F | 55°F | -- | -- |
| 2004 | 77°F | 59°F | -- | -- |
| 2003 | 84°F | 61°F | -- | -- |
| 2002 | 82°F | 57°F | -- | -- |
| 2001 | 94°F | 68°F | -- | -- |
| 2000 | 93°F | 64°F | -- | -- |
| 1999 | 104°F | 80°F | -- | -- |
| 1998 | 95°F | 63°F | -- | -- |
| 1997 | 92°F | 65°F | -- | -- |
| 1996 | 98°F | 73°F | -- | -- |
Based on 30 years of data from NOAA station: SIMI VALLEY CALIFORNIA
Monthly Climate Averages
Historical temperature and precipitation averages for Simi Valley, CA, based on 55+ years of weather data.
Temperatures in Fahrenheit. Precipitation and snowfall in inches.