San Bernardino, CA weather in August
Expect hot, dry weather in San Bernardino in August, with highs near 96°F and lows near 63°F. Rain falls on about 1 day. It is one of the warmest months in San Bernardino. Plan outdoor time for mornings and evenings.
- Normal high
- 96°F
- Normal low
- 63°F
- Wet days
- 1
- 0.09 in total
- Muggy days
- 0
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 96°F | 96°F |
| Normal low | 64°F | 62°F |
| Chance of a wet day | 3% | 3% |
| Sunrise / sunset | 6:00 am / 7:50 pm | 6:22 am / 7:16 pm |
| Daylight | 13.8 h | 12.9 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 am65°Fdew point 56°F
- 9 am81°Fdew point 55°F
- Noon92°Fdew point 52°F
- 3 pm93°Fdew point 53°F
- 6 pm84°Fdew point 53°F
- 9 pm73°Fdew point 55°F
NOAA hourly normals (local standard time) from March AFB (15 mi away); average wind 6 mph; clear or few clouds in 85% of daytime hours, mostly cloudy or overcast in 8%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
- Hot dayshigh 90°F or more26 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 0.09 in; a dry August brings about 0.0 in and a wet one about 0.03 in (25th and 75th percentiles). Days with half an inch or more are rare.
How August varies from year to year
- Warmest August, 1991-20201998: average high 100°F
- Coolest August2014: average high 91°F
- Wettest August2014: 1.3 in
- Driest August1991: no measurable precipitation
- Highest reading113°F (August 30, 2007)
- Lowest reading46°F (August 30, 2010)
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 | 95°F | 96°F | 92°F |
| Normal low | 63°F | 63°F | 60°F |
| Wet days | 1 | 1 | 1 |
| Comfortable days | 0 | 0 | 4 |
| Daylight | 14.2 h | 13.4 h | 12.4 h |
Highs change by +1°F from July and -4°F into September.
Nearby alternatives in August
- Warmer: Palm Springs, CA47 mi · high 108°F · 1 wet day
- Cooler: Big Bear Lake, CA24 mi · high 79°F · 3 wet days
How San Bernardino ranks in August
- Normal high39th warmest of 378 cities; 12th of 60 in California
- Wet days49th driest of 378
- Comfortable days231st most of 341
What to pack for San Bernardino in August
- Light, breathable clothing – highs near 96°F
- Layers – afternoons near 96°F but nights near 63°F
Heating and cooling
August has 0 heating degree days and 451 cooling degree days (base 65°F), 13% of the year's total heating and cooling demand.
Questions
How hot is San Bernardino in August?
The normal high is 96°F and the normal low is 63°F. From 1991 to 2020 the hottest August reading was 113°F (August 30, 2007).
Does it rain a lot in San Bernardino in August?
About 1 days in August have at least 0.01 in of precipitation, and the normal total is 0.09 in. The wettest August in 1991-2020 was in 2014 (1.3 in); the driest was in 1991, with no measurable precipitation.
Is August a good time to visit San Bernardino?
August ranks 12th of 12 months on our comfort score for San Bernardino (39 out of 100). It has almost no comfortable days and about 26 days at 90°F or hotter. The best months are March, April and May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Redlands (USC00047306), 7.3 mi SE of the city center, 1,410 ft (359 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: March AFB (USW00023119), 15 mi S of the city center, 1,516 ft (465 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: March Air Reserve Base (722860-23119), 15 mi S of the city center, 1,536 ft (485 ft higher than the city). Hourly observations, 1991-2020.