Climate averages 1991–2020
Merced weather
in September.
A hot, very dry month: the 4th warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Merced: daytime highs average 32.2°C and nights cool to about 17.3°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 1.7 mm of rain on fewer than one day, which makes September a very dry month (the 3rd 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 Turlock (39 km away). In September its highs average 31.8°C, about as warm as Merced, with 1.9 mm of rain.
Among the 498 cities listed in the United States, Merced ranks 26th of 498 for the warmest September highs and joint 11th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Merced is 5.3°C warmer than that mean.
From September to October, average highs fall by 6.3°C to 26.0°C, and monthly rainfall rises from 1.7 mm to 21 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
Merced climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 14.2°C4.3°C | 4.3°C | 90 | 8.1 | 9.910 h |
| February | 16.0°C5.6°C | 5.6°C | 80 | 8.5 | 10.811 h |
| March | 18.9°C7.6°C | 7.6°C | 71 | 7.7 | 11.912 h |
| April | 22.5°C9.9°C | 9.9°C | 32 | 4.7 | 13.113 h |
| May | 27.8°C13.7°C | 13.7°C | 19 | 2.8 | 14.114 h |
| June | 32.9°C17.3°C | 17.3°C | 3.6 | 0.6 | 14.715 h |
| July | 36.2°C20.2°C | 20.2°C | 0.6 | 0.2 | 14.514 h |
| August | 35.3°C19.6°C | 19.6°C | 0.6 | 0.1 | 13.614 h |
| September, selected | 32.2°C17.3°C | 17.3°C | 1.7 | 0.4 | 12.512 h |
| October | 26.0°C12.7°C | 12.7°C | 21 | 2.3 | 11.311 h |
| November | 18.7°C7.6°C | 7.6°C | 37 | 4.8 | 10.210 h |
| December | 13.9°C4.4°C | 4.4°C | 75 | 7.4 | 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
- Turlock in SeptemberUnited States · 39 kmHigh 31.8°C · Low 17.1°C · 1.9 mm rain
- Modesto in SeptemberUnited States · 59 kmHigh 31.3°C · Low 16.3°C · 1.9 mm rain
- Manteca in SeptemberUnited States · 85 kmHigh 30.3°C · Low 15.3°C · 1.9 mm rain
- Clovis in SeptemberUnited States · 87 kmHigh 32.5°C · Low 17.6°C · 1.8 mm rain
- Fresno in SeptemberUnited States · 88 kmHigh 32.6°C · Low 18.2°C · 1.8 mm rain
- Tracy in SeptemberUnited States · 96 kmHigh 30.7°C · Low 15.2°C · 1.8 mm rain
- Stockton in SeptemberUnited States · 102 kmHigh 30.1°C · Low 15.1°C · 2.1 mm rain
- Livermore in SeptemberUnited States · 121 kmHigh 28.3°C · Low 14.3°C · 1.7 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 Merced) is explained once on the Merced year overview and on the Sources, method and limits page.