Santa Rosa, CA weather in August
Expect warm, dry weather in Santa Rosa in August, with highs near 84°F and lows near 50°F. Rain falls on about 1 day. It is one of the warmest months in Santa Rosa. Good for outdoor plans.
- Normal high
- 84°F
- Normal low
- 50°F
- Wet days
- 1
- 0.06 in total
- Muggy days
- 0
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 83°F | 85°F |
| Normal low | 51°F | 49°F |
| Chance of a wet day | 2% | 4% |
| Sunrise / sunset | 6:13 am / 8:21 pm | 6:39 am / 7:42 pm |
| Daylight | 14.1 h | 13.1 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 am59°Fdew point 54°F
- 9 am71°Fdew point 54°F
- Noon82°Fdew point 53°F
- 3 pm88°Fdew point 52°F
- 6 pm79°Fdew point 54°F
- 9 pm66°Fdew point 53°F
NOAA hourly normals (local standard time) from Travis AFB (44 mi away); average wind 17 mph; clear or few clouds in 91% of daytime hours, mostly cloudy or overcast in 5%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F11 of 31
- Hot dayshigh 90°F or more8 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow1 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 0.06 in; a dry August brings about 0.0 in and a wet one about 0.02 in (25th and 75th percentiles). Days with half an inch or more are rare.
How August varies from year to year
- Warmest August, 1991-20202020: average high 90°F
- Coolest August2010: average high 80°F
- Wettest August1997: 1.4 in
- Driest August1992: no measurable precipitation
- Highest reading109°F (August 14, 2020)
- Lowest reading35°F (August 31, 2007)
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 | 83°F | 84°F | 84°F |
| Normal low | 51°F | 50°F | 48°F |
| Wet days | 0 | 1 | 2 |
| Comfortable days | 11 | 11 | 9 |
| Daylight | 14.5 h | 13.6 h | 12.4 h |
Highs change by +1°F from July and 0°F into September.
Nearby alternatives in August
- Warmer: Fairfield, CA39 mi · high 89°F · 0 wet days
- Cooler: San Francisco, CA49 mi · high 68°F · 1 wet day
How Santa Rosa ranks in August
- Normal high232nd warmest of 378 cities; 39th of 60 in California
- Wet days52nd driest of 378
- Comfortable days58th most of 341
What to pack for Santa Rosa in August
- Layers – afternoons near 84°F but nights near 50°F
Heating and cooling
August has 22 heating degree days and 85 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Santa Rosa in August?
The normal high is 84°F and the normal low is 50°F. From 1991 to 2020 the hottest August reading was 109°F (August 14, 2020).
Does it rain a lot in Santa Rosa in August?
About 1 days in August have at least 0.01 in of precipitation, and the normal total is 0.06 in. The wettest August in 1991-2020 was in 1997 (1.4 in); the driest was in 1992, with no measurable precipitation.
Is August a good time to visit Santa Rosa?
August ranks 6th of 12 months on our comfort score for Santa Rosa (66 out of 100). It has about 11 comfortable days and about 8 days at 90°F or hotter. The best months are April and May.
Where the numbers come from
- Temperature and rain: Graton (USC00043578), 8.2 mi W of the city center, 200 ft . NOAA normals and daily records, 1991-2020.
- Snowfall, snow depth and frost dates: Santa Rosa (USC00047965), 1.1 mi N of the city center, 166 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Travis AFB (USW00023202), 44 mi ESE of the city center, 59 ft (106 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Sonoma County Airport (724957-23213), 6.8 mi NW of the city center, 119 ft . Hourly observations, 1991-2020.