Santa Clara, CA weather in September
September in Santa Clara: mild and dry. Highs 78°F, lows 57°F, about 1 day with rain. This is the peak of the warm season in Santa Clara. A great month for outdoor plans.
- Normal high
- 78°F
- Normal low
- 57°F
- Wet days
- 1
- 0.07 in total
- Muggy days
- 0
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 78°F | 77°F |
| Normal low | 58°F | 56°F |
| Chance of a wet day | 2% | 5% |
| Sunrise / sunset | 6:38 am / 7:37 pm | 7:02 am / 6:53 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 53°F
- 9 am64°Fdew point 55°F
- Noon70°Fdew point 55°F
- 3 pm71°Fdew point 53°F
- 6 pm64°Fdew point 53°F
- 9 pm61°Fdew point 53°F
NOAA hourly normals (local standard time) from San Francisco Intl Airport (29 mi away); average wind 11 mph; clear or few clouds in 64% of daytime hours, mostly cloudy or overcast in 20%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F21 of 30
- Hot dayshigh 90°F or more3 of 30
- Muggy daysdaily mean dew point 65°F or more0 of 30
- Wet daysat least 0.01 in of rain or melted snow1 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 0.07 in; a dry September brings about 0.0 in and a wet one about 0.06 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20202017: average high 83°F
- Coolest September2012: average high 74°F
- Wettest September2013: 0.7 in
- Driest September2002: no measurable precipitation
- Highest reading106°F (September 2, 2017)
- Lowest reading48°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 | 77°F | 78°F | 74°F |
| Normal low | 59°F | 57°F | 53°F |
| Wet days | 0 | 1 | 3 |
| Comfortable days | 23 | 21 | 23 |
| Daylight | 13.6 h | 12.4 h | 11.2 h |
Highs change by +1°F from August and -4°F into October.
Nearby alternatives in September
- Warmer: Tracy, CA39 mi · high 90°F · 1 wet day
- Cooler: San Francisco, CA39 mi · high 70°F · 1 wet day
How Santa Clara ranks in September
- Normal high227th warmest of 378 cities; 45th of 60 in California
- Wet days36th driest of 378
- Comfortable days14th most of 342
Heating and cooling
September has 18 heating degree days and 93 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Santa Clara in September?
The normal high is 78°F and the normal low is 57°F. From 1991 to 2020 the hottest September reading was 106°F (most recently on September 2, 2017).
Does it rain a lot in Santa Clara in September?
About 1 days in September have at least 0.01 in of precipitation, and the normal total is 0.07 in. The wettest September in 1991-2020 was in 2013 (0.7 in); the driest was in 2002, with no measurable precipitation.
Is September a good time to visit Santa Clara?
September ranks 5th of 12 months on our comfort score for Santa Clara (79 out of 100). It has about 21 comfortable days and about 3 days at 90°F or hotter. The best months are May, June and July.
Where the numbers come from
- Temperature: Moffett Federal Airfield (USW00023244), 6.2 mi NW of the city center, 39 ft . NOAA normals and daily records, 1991-2020.
- Rain and frost dates: San Jose (USW00023293), 1.8 mi ENE of the city center, 51 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: San Jose (USC00047821), 2.9 mi E of the city center, 67 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: San Francisco Intl Airport (USW00023234), 29 mi NW of the city center, 8 ft (64 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: N Y. Mineta Sn Jo Intl Apt (724945-23293), 1.8 mi E of the city center, 49 ft . Hourly observations, 1991-2020.