- Simi Valley ›
- Weather by month
Simi Valley Weather by Month
Average temperatures, rainfall and humidity for Simi Valley, United States, month by month, built from OpenWeather’s historical records. Use it to see what a typical Simi Valley month looks like before you travel — then check the live Simi Valley forecast for the days ahead.
Warmest month
August
30°C average high
Coolest month
February
9°C average low
Wettest month
December
55 mm of rain
Driest month
June
3 mm of rain
Average temperature and rainfall in Simi Valley by month
Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.
| Month | Avg high | Avg low | Record low / high | Rainfall | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 19°C | 9°C | -5°C / 30°C | 45 mm | 57% | 10 km/h |
| February | 19°C | 9°C | -2°C / 33°C | 50 mm | 59% | 9 km/h |
| March | 20°C | 10°C | 2°C / 36°C | 37 mm | 65% | 9 km/h |
| April | 22°C | 11°C | 2°C / 36°C | 15 mm | 63% | 8 km/h |
| May | 23°C | 12°C | 6°C / 37°C | 16 mm | 69% | 7 km/h |
| June | 26°C | 15°C | 10°C / 40°C | 3 mm | 70% | 7 km/h |
| July | 29°C | 17°C | 12°C / 38°C | 4 mm | 66% | 7 km/h |
| August | 30°C | 18°C | 12°C / 40°C | 3 mm | 64% | 7 km/h |
| September | 29°C | 17°C | 10°C / 44°C | 4 mm | 65% | 7 km/h |
| October | 26°C | 14°C | 3°C / 40°C | 8 mm | 60% | 7 km/h |
| November | 22°C | 11°C | -1°C / 34°C | 21 mm | 55% | 9 km/h |
| December | 19°C | 9°C | -2°C / 29°C | 55 mm | 59% | 9 km/h |
Best time to visit Simi Valley
The most comfortable time to visit Simi Valley is generally April to June, balancing mild daytime temperatures against the driest stretch of the year. The city has a moderate seasonal swing and rain concentrates around December, totalling about 262 mm a year.
Travellers who prefer heat should aim for August, when highs average 30°C. December is the month to avoid if rain would spoil your plans — it averages 55 mm, roughly 19× the rainfall of the driest month (June).
Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Simi Valley forecast for what is happening now.