San Mateo, CA weather in August
In August, San Mateo sees highs around 73°F and lows around 56°F: mild and dry. Rain is rare. It is one of the warmest months in San Mateo. Great for outdoor plans.
- Normal high
- 73°F
- Normal low
- 56°F
- Wet days
- 0
- 0.04 in total
- Muggy days
- 0
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 73°F | 74°F |
| Normal low | 56°F | 56°F |
| Chance of a wet day | 1% | 1% |
| Sunrise / sunset | 6:13 am / 8:17 pm | 6:38 am / 7:40 pm |
| Daylight | 14.1 h | 13.0 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 August day
- 6 am58°Fdew point 54°F
- 9 am64°Fdew point 55°F
- Noon70°Fdew point 55°F
- 3 pm70°Fdew point 54°F
- 6 pm64°Fdew point 54°F
- 9 pm60°Fdew point 54°F
NOAA hourly normals (local standard time) from San Francisco Intl Airport (5 mi away); average wind 12 mph; clear or few clouds in 65% of daytime hours, mostly cloudy or overcast in 17%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F27 of 31
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph1 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow0 of 31
- Notable rainat least 0.10 in0 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 0.04 in; a dry August brings about 0.0 in and a wet one about 0.0 in (25th and 75th percentiles). Days with half an inch or more are rare.
How August varies from year to year
- Warmest August, 1991-20202019: average high 77°F
- Coolest August2012: average high 69°F
- Wettest August1997: 0.6 in
- Driest August1993: no measurable precipitation
- Highest reading99°F (August 14, 2020)
- Lowest reading50°F (August 6, 2018)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 73°F | 73°F | 75°F |
| Normal low | 55°F | 56°F | 56°F |
| Wet days | 0 | 0 | 1 |
| Comfortable days | 28 | 27 | 23 |
| Daylight | 14.5 h | 13.6 h | 12.4 h |
Highs change by 0°F from July and +2°F into September.
Nearby alternatives in August
- Warmer: San Jose, CA28 mi · high 81°F · 0 wet days
- Cooler: San Francisco, CA16 mi · high 68°F · 1 wet day
How San Mateo ranks in August
- Normal high360th warmest of 378 cities; 56th of 60 in California
- Wet days42nd driest of 378
- Comfortable days4th most of 341
Heating and cooling
August has 44 heating degree days and 41 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is San Mateo in August?
The normal high is 73°F and the normal low is 56°F. From 1991 to 2020 the hottest August reading was 99°F (most recently on August 14, 2020).
Does it rain a lot in San Mateo in August?
About 0 days in August have at least 0.01 in of precipitation, and the normal total is 0.04 in. The wettest August in 1991-2020 was in 1997 (0.6 in); the driest was in 1993, with no measurable precipitation.
Is August a good time to visit San Mateo?
August ranks 2nd of 12 months on our comfort score for San Mateo (91 out of 100). It has about 27 comfortable days and about 1 day at 90°F or hotter. The best months are July and August.
Where the numbers come from
- Temperature, rain, frost dates, humidity and wind by hour and cloud cover: San Francisco Intl Airport (USW00023234), 4.5 mi NNW of the city center, 8 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Redwood City (USC00047339), 7.6 mi SE of the city center, 31 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: San Francisco International Airport (724940-23234), 4.5 mi NNW of the city center, 10 ft . Hourly observations, 1991-2020.