Climate averages 1991–2020
Thousand Oaks weather
in September.
A hot, very dry month: the 3rd warmest and the 4th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Thousand Oaks: daytime highs average 28.4°C and nights cool to about 17.7°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 3.9 mm of rain on fewer than one day, which makes September a very dry month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 25 min on an average September day.
The nearest other city in this atlas is Simi Valley (12 km away). In September its highs average 29.5°C, 1.1°C warmer than Thousand Oaks, with 3.9 mm of rain.
Among the 498 cities listed in the United States, Thousand Oaks ranks joint 191st of 498 for the warmest September highs and joint 63rd of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Thousand Oaks is 1.5°C warmer than that mean.
From September to October, average highs fall by 3.3°C to 25.1°C, and monthly rainfall rises from 3.9 mm to 20 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Thousand Oaks climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 17.6°C6.6°C | 6.6°C | 91 | 5.6 | 10.210 h |
| February | 17.5°C6.9°C | 6.9°C | 98 | 6.4 | 10.911 h |
| March | 18.9°C8.3°C | 8.3°C | 66 | 5.6 | 11.912 h |
| April | 20.9°C10.0°C | 10.0°C | 22 | 2.9 | 13.013 h |
| May | 22.9°C12.9°C | 12.9°C | 12 | 1.8 | 13.914 h |
| June | 25.8°C15.6°C | 15.6°C | 2.0 | 0.5 | 14.414 h |
| July | 28.5°C18.4°C | 18.4°C | 3.1 | 0.5 | 14.214 h |
| August | 29.5°C19.1°C | 19.1°C | 0.3 | 0.1 | 13.413 h |
| September, selected | 28.4°C17.7°C | 17.7°C | 3.9 | 0.6 | 12.412 h |
| October | 25.1°C14.1°C | 14.1°C | 20 | 2.1 | 11.411 h |
| November | 21.2°C9.8°C | 9.8°C | 21 | 2.6 | 10.410 h |
| December | 17.4°C6.5°C | 6.5°C | 58 | 4.8 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Simi Valley in SeptemberUnited States · 12 kmHigh 29.5°C · Low 17.6°C · 3.9 mm rain
- Oxnard in SeptemberUnited States · 31 kmHigh 24.3°C · Low 17.2°C · 3.1 mm rain
- Santa Clarita in SeptemberUnited States · 37 kmHigh 31.1°C · Low 17.4°C · 4.4 mm rain
- Valencia, United States in SeptemberUnited States · 37 kmHigh 31.3°C · Low 17.5°C · 4.4 mm rain
- Ventura in SeptemberUnited States · 44 kmHigh 25.9°C · Low 17.5°C · 3.1 mm rain
- Burbank in SeptemberUnited States · 49 kmHigh 31.8°C · Low 18.0°C · 3.9 mm rain
- Inglewood in SeptemberUnited States · 50 kmHigh 29.0°C · Low 17.5°C · 3.2 mm rain
- Hawthorne in SeptemberUnited States · 53 kmHigh 27.9°C · Low 17.1°C · 3.2 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Thousand Oaks) is explained once on the Thousand Oaks year overview and on the Sources, method and limits page.
Simi Valley lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.