Climate averages 1991–2020
Antioch weather
in September.
A hot, very dry month: the 3rd warmest and the 2nd 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 Antioch: daytime highs average 28.8°C and nights cool to about 14.8°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 1.2 mm of rain on fewer than one day, which makes September a very dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 28 min on an average September day.
The nearest other city in this atlas is Concord (California), United States (20 km away). In September its highs average 28.2°C, 0.6°C cooler than Antioch, with 1.5 mm of rain.
Among the 498 cities listed in the United States, Antioch ranks joint 181st of 498 for the warmest September highs and 3rd of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Antioch is 1.9°C warmer than that mean.
From September to October, average highs fall by 4.4°C to 24.4°C, and monthly rainfall rises from 1.2 mm to 22 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
Antioch climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 13.9°C5.9°C | 5.9°C | 93 | 9.0 | 9.810 h |
| February | 15.7°C6.8°C | 6.8°C | 91 | 8.9 | 10.811 h |
| March | 18.0°C8.1°C | 8.1°C | 69 | 8.3 | 11.912 h |
| April | 20.9°C9.4°C | 9.4°C | 31 | 4.7 | 13.213 h |
| May | 24.7°C11.9°C | 11.9°C | 16 | 3.0 | 14.214 h |
| June | 28.5°C14.0°C | 14.0°C | 3.6 | 0.7 | 14.815 h |
| July | 30.2°C15.1°C | 15.1°C | 0.4 | 0.2 | 14.515 h |
| August | 30.0°C15.4°C | 15.4°C | 1.5 | 0.2 | 13.614 h |
| September, selected | 28.8°C14.8°C | 14.8°C | 1.2 | 0.3 | 12.512 h |
| October | 24.4°C12.8°C | 12.8°C | 22 | 2.8 | 11.211 h |
| November | 17.9°C9.1°C | 9.1°C | 45 | 5.4 | 10.210 h |
| December | 13.7°C6.3°C | 6.3°C | 87 | 8.4 | 9.610 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
- Concord (California), United States in SeptemberUnited States · 20 kmHigh 28.2°C · Low 14.1°C · 1.5 mm rain
- San Ramon in SeptemberUnited States · 29 kmHigh 27.4°C · Low 14.1°C · 1.7 mm rain
- Fairfield in SeptemberUnited States · 34 kmHigh 28.9°C · Low 14.3°C · 1.5 mm rain
- Livermore in SeptemberUnited States · 36 kmHigh 28.3°C · Low 14.3°C · 1.7 mm rain
- Pleasanton in SeptemberUnited States · 39 kmHigh 28.0°C · Low 14.4°C · 1.7 mm rain
- Vallejo in SeptemberUnited States · 41 kmHigh 28.2°C · Low 13.5°C · 1.8 mm rain
- Vacaville in SeptemberUnited States · 42 kmHigh 30.4°C · Low 15.3°C · 1.5 mm rain
- Berkeley in SeptemberUnited States · 44 kmHigh 26.2°C · Low 13.2°C · 1.4 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 Antioch) is explained once on the Antioch year overview and on the Sources, method and limits page.