Modesto, CA weather in September
Modesto is hot and dry in September: highs average 89°F and nights drop to about 59°F. Rain is rare.
- Normal high
- 89°F
- Normal low
- 59°F
- Wet days
- 0
- 0.06 in total
- Muggy days
- 0
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 92°F | 85°F |
| Normal low | 61°F | 56°F |
| Chance of a wet day | 1% | 3% |
| Sunrise / sunset | 6:34 am / 7:33 pm | 6:58 am / 6:49 pm |
| Daylight | 13.0 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical September day
- 6 am58°Fdew point 51°F
- 9 am72°Fdew point 52°F
- Noon83°Fdew point 51°F
- 3 pm88°Fdew point 50°F
- 6 pm81°Fdew point 50°F
- 9 pm70°Fdew point 51°F
NOAA hourly normals (local standard time) from Stockton Metro Airport (21 mi away); average wind 7 mph; clear or few clouds in 94% of daytime hours, mostly cloudy or overcast in 4%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F4 of 30
- Hot dayshigh 90°F or more15 of 30
- Muggy daysdaily mean dew point 65°F or more0 of 30
- Wet daysat least 0.01 in of rain or melted snow0 of 30
- Notable rainat least 0.10 in0 of 30
- Freezing nightslow 32°F or below0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 0.06 in; a dry September brings about 0.0 in and a wet one about 0.1 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20202011: average high 92°F
- Coolest September2005: average high 86°F
- Wettest September2014: 0.3 in
- Driest September1991: no measurable precipitation
- Highest reading108°F (September 2, 2017)
- Lowest reading45°F (September 30, 2007)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 94°F | 89°F | 79°F |
| Normal low | 62°F | 59°F | 52°F |
| Wet days | 0 | 0 | 2 |
| Comfortable days | 0 | 4 | 17 |
| Daylight | 13.6 h | 12.4 h | 11.2 h |
Highs change by -5°F from August and -10°F into October.
Nearby alternatives in September
- Warmer: Furnace Creek, CA242 mi · high 108°F · 1 wet day
- Cooler: San Jose, CA53 mi · high 81°F · 1 wet day
How Modesto ranks in September
- Normal high67th warmest of 378 cities; 23rd of 60 in California
- Wet days4th driest of 378
- Comfortable days223rd most of 342
What to pack for Modesto in September
- Light, breathable clothing – highs near 89°F
- Layers – afternoons near 89°F but nights near 59°F
Heating and cooling
September has 4 heating degree days and 269 cooling degree days (base 65°F), 7% of the year's total heating and cooling demand.
Questions
How hot is Modesto in September?
The normal high is 89°F and the normal low is 59°F. From 1991 to 2020 the hottest September reading was 108°F (September 2, 2017).
Does it rain a lot in Modesto in September?
About 0 days in September have at least 0.01 in of precipitation, and the normal total is 0.06 in. The wettest September in 1991-2020 was in 2014 (0.3 in); the driest was in 1991, with no measurable precipitation.
Is September a good time to visit Modesto?
September ranks 8th of 12 months on our comfort score for Modesto (48 out of 100). It has about 4 comfortable days and about 15 days at 90°F or hotter. The best month is April.
Where the numbers come from
- Temperature, rain and frost dates: Modesto City Co Airport (USW00023258), 2.7 mi ESE of the city center, 73 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Turlock #2 (USC00049073), 13 mi SE of the city center, 103 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Stockton Metro Airport (USW00023237), 21 mi NW of the city center, 26 ft (62 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Mdsto Cty-Co H Sham Fd Apt (724926-23258), 2.5 mi ESE of the city center, 87 ft . Hourly observations, 1991-2020.