Weather on December 17
Simi Valley, CA
55 Years of Data
Avg High
65°F
Avg Low
51°F
Warmest
2013
75°F avg
Coldest
2008
43°F avg
About This Date
December 17th in Simi Valley, CA typically brings mild winter weather, with average highs around 65°F and lows near 51°F. Over 31 years of records, the warmest December 17th was in 2013 (75°F average), while the coldest was 2008 (43°F) — a 32°F range across recorded history. This date has historically been dry, with little recorded precipitation. The last decade has been 4.1°F cooler on this date compared to 20-30 years ago.
The last decade has been 4.1°F cooler on this date compared to 20-30 years ago.
Planning for December 17th in Simi Valley, CA? Great weather for outdoor activities.
Cooling Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 61° | 69° | — | — |
| 2024 | 72° | 56° | 64° | — | — |
| 2023 | 75° | 62° | 69° | — | — |
| 2022 | 62° | 46° | 54° | — | — |
| 2021 | 60° | 44° | 52° | — | — |
| 2020 | 64° | 51° | 58° | — | — |
| 2019 | 61° | 49° | 55° | — | — |
| 2018 | 61° | 48° | 54° | — | — |
| 2017 | 60° | 50° | 55° | — | — |
| 2016 | 53° | 40° | 46° | — | — |
| 2015 | 63° | 46° | 54° | — | — |
| 2014 | 60° | 47° | 53° | — | — |
| 2013warmest | 84° | 66° | 75° | — | — |
| 2012 | 56° | 48° | 52° | — | — |
| 2011 | 63° | 52° | 57° | — | — |
| 2010 | 55° | 49° | 52° | — | — |
| 2009 | 68° | 57° | 63° | — | — |
| 2008coldest | 46° | 39° | 43° | — | — |
| 2007 | 57° | 36° | 46° | — | — |
| 2006 | 52° | 36° | 44° | — | — |
| 2005 | 57° | 48° | 53° | — | — |
| 2004 | 70° | 59° | 64° | — | — |
| 2003 | 66° | 55° | 61° | — | — |
| 2002 | 55° | 41° | 48° | — | — |
| 2001 | 61° | 45° | 53° | — | — |
| 2000 | 81° | 59° | 70° | — | — |
| 1999 | 84° | 62° | 73° | — | — |
| 1998 | 82° | 62° | 72° | — | — |
| 1997 | 72° | 48° | 60° | — | — |
| 1996 | 69° | 58° | 63° | — | — |
| 1995 | 61° | 49° | 55° | — | — |
31 years of data from SIMI VALLEY CALIFORNIA