Weather on March 18
Simi Valley, CA
55 Years of Data
About This Date
March 18th in Simi Valley, CA typically brings pleasant spring weather, with average highs around 70°F and lows near 50°F. Over 31 years of records, the warmest March 18th was in 2026 (82°F average), while the coldest was 2012 (45°F) — a 37°F range across recorded history. This date has historically been dry, with little recorded precipitation. The last decade has been 2.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.0°F warmer on this date compared to 20-30 years ago.
Planning for March 18th in Simi Valley, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026warmest | 90° | 74° | 82° | — | — |
| 2025 | 62° | 42° | 52° | — | — |
| 2024 | 75° | 53° | 64° | — | — |
| 2023 | 69° | 55° | 62° | — | — |
| 2022 | 81° | 60° | 70° | — | — |
| 2021 | 69° | 47° | 58° | — | — |
| 2020 | 61° | 42° | 51° | — | — |
| 2019 | 78° | 57° | 68° | — | — |
| 2018 | 62° | 42° | 52° | — | — |
| 2017 | 76° | 50° | 63° | — | — |
| 2016 | 75° | 50° | 63° | — | — |
| 2015 | 70° | 56° | 63° | — | — |
| 2014 | 74° | 50° | 62° | — | — |
| 2013 | 66° | 46° | 56° | — | — |
| 2012coldest | 52° | 39° | 45° | — | — |
| 2011 | 63° | 43° | 53° | — | — |
| 2010 | 77° | 54° | 65° | — | — |
| 2009 | 82° | 59° | 71° | — | — |
| 2008 | 68° | 45° | 56° | — | — |
| 2007 | 61° | 50° | 55° | — | — |
| 2006 | 57° | 41° | 49° | — | — |
| 2005 | 57° | 46° | 52° | — | — |
| 2004 | 72° | 46° | 59° | — | — |
| 2003 | 64° | 46° | 55° | — | — |
| 2002 | 63° | 39° | 51° | — | — |
| 2001 | 82° | 59° | 71° | — | — |
| 2000 | 76° | 63° | 69° | — | — |
| 1999 | 61° | 45° | 53° | — | — |
| 1998 | 70° | 50° | 60° | — | — |
| 1997 | 88° | 55° | 71° | — | — |
| 1996 | 74° | 50° | 62° | — | — |
Simi Valley, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Simi Valley, CA Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Simi Valley, CA
Most pleasant months in Simi Valley, CA: January, March, April, May, June, October, November.