Climate averages 1991–2020
Chula Vista weather
in September.
A warm, very dry month: the 2nd 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 warm month in Chula Vista: daytime highs average 24.2°C and nights cool to about 17.6°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 4.4 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 24 min on an average September day.
The nearest other city in this atlas is San Diego (11 km away). In September its highs average 25.1°C, 0.9°C warmer than Chula Vista, with 2.9 mm of rain.
Among the 498 cities listed in the United States, Chula Vista ranks joint 342nd of 498 for the warmest September highs and joint 82nd of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Chula Vista is 2.7°C cooler than that mean.
From September to October, average highs fall by 1.9°C to 22.3°C, and monthly rainfall rises from 4.4 mm to 15 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
Chula Vista climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 17.1°C9.3°C | 9.3°C | 57 | 5.6 | 10.310 h |
| February | 16.8°C9.7°C | 9.7°C | 74 | 6.9 | 11.011 h |
| March | 17.3°C10.6°C | 10.6°C | 48 | 5.8 | 12.012 h |
| April | 18.4°C11.9°C | 11.9°C | 23 | 3.9 | 13.013 h |
| May | 19.4°C13.6°C | 13.6°C | 10 | 2.0 | 13.814 h |
| June | 21.2°C15.0°C | 15.0°C | 1.8 | 0.6 | 14.314 h |
| July | 23.5°C17.2°C | 17.2°C | 2.6 | 0.7 | 14.114 h |
| August | 24.5°C18.1°C | 18.1°C | 1.8 | 0.5 | 13.413 h |
| September, selected | 24.2°C17.6°C | 17.6°C | 4.4 | 0.9 | 12.412 h |
| October | 22.3°C15.3°C | 15.3°C | 15 | 2.5 | 11.411 h |
| November | 19.8°C12.1°C | 12.1°C | 24 | 3.3 | 10.511 h |
| December | 17.0°C9.4°C | 9.4°C | 47 | 5.3 | 10.010 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
- San Diego in SeptemberUnited States · 11 kmHigh 25.1°C · Low 17.5°C · 2.9 mm rain
- Tijuana in SeptemberMexico · 17 kmHigh 24.4°C · Low 17.9°C · 4.0 mm rain
- El Cajon in SeptemberUnited States · 21 kmHigh 27.6°C · Low 17.8°C · 4.4 mm rain
- Rosarito in SeptemberMexico · 31 kmHigh 24.5°C · Low 18.5°C · 3.1 mm rain
- Escondido in SeptemberUnited States · 53 kmHigh 28.1°C · Low 17.5°C · 5.1 mm rain
- San Marcos in SeptemberUnited States · 56 kmHigh 26.2°C · Low 17.3°C · 3.9 mm rain
- Vista in SeptemberUnited States · 64 kmHigh 28.0°C · Low 18.1°C · 3.9 mm rain
- Oceanside in SeptemberUnited States · 68 kmHigh 25.3°C · Low 18.4°C · 3.3 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 Chula Vista) is explained once on the Chula Vista year overview and on the Sources, method and limits page.
El Cajon lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.