San Bruno weather in August

In August, San Bruno sees average daytime highs of 66°F and overnight lows near 56°F, with 0.0 in of rain across 0.1 wet days and about 13.4 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 66°F through the month. The sky is clear or mostly clear about 57% of the time in August, and the air most often feels dry.

Daylight stretches from about 14 hours at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is San Bruno's 4th-clearest and 7th-windiest month. For the whole year in context, see San Bruno's year-round climate.

Daytime high
66°
2nd warmest
Overnight low
56°
12th coldest
Rainfall
0.0 in
0.1 wet days
Daylight
13 h 30 min
5:30 AM – 6:58 PM
Cloud cover
37%
4th clearest
Wind
8 mph
7th windiest
Solar energy
6.73 kWh/m²
Travel score
7.9
out of 10

San Bruno is city in San Mateo County, California, United States.

Density
3,044/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 66°F through the month.

A typical August day in San Bruno reaches about 66°F in the afternoon and slips back to 56°F overnight — a 10°F spread between the day's warmth and the night's chill. On most days the high lands between 62°F and 71°F. Set against its neighbours, August runs on par with July and on par with September.

50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16556
26556
36556
46556
56556
66556
76556
86656
96656
106656
116656
126656
136656
146656
156656
166656
176656
186656
196656
206656
216656
226656
236656
246756
256756
266756
276756
286756
296756
306756
316756

San Bruno weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan55° / 47°4.310.19.73.7
Feb57° / 48°4.49.310.54.0
Mar58° / 49°3.29.311.74.5
Apr59° / 50°1.5512.95.4
May61° / 52°0.72.8146.3
Jun64° / 54°0.20.814.57.5
Jul65° / 55°0.00.114.37.8
Aug66° / 56°0.00.113.47.9
Sep67° / 56°0.10.412.38.1
Oct65° / 54°0.93.1117.5
Nov60° / 50°2.26.1105.4
Dec56° / 47°4.210.19.43.8

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 57% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 25% of August, with mostly cloudy or overcast conditions the remaining 18%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
18020
27921
37921
48020
58020
68020
78020
88020
98020
108020
118020
127921
138020
148020
158020
168119
178119
188119
198119
208218
218218
228218
238317
248317
258515
268515
278614
288614
298713
308713
318812

Chance of precipitation in August

Any precipitation

San Bruno gets around 0.0 in of rain over 0.1 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 0% and peaks near 1% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
211
221
231
241
251
261
271
281
291
301
311

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the dry band about 60% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
171290
270300
368320
467330
566340
665350
763370
862380
961390
1061390
1160400
1259410
1359410
1459410
1558420
1658420
1757421
1857421
1957421
2057421
2157421
2257421
2356422
2456422
2556422
2656422
2756422
2857412
2957412
3058402
3159392

Wind in August

Winds average 8 mph in August.

Across August, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 hours at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 5:17 AM to 5:43 AM, and sunset from 7:15 PM to 6:36 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:177:15
213.95:187:14
313.95:197:13
413.95:197:12
513.85:207:11
613.85:217:09
713.85:227:08
813.75:237:07
913.75:247:06
1013.75:257:05
1113.65:257:04
1213.65:267:03
1313.65:277:01
1413.55:287:00
1513.55:296:59
1613.55:306:58
1713.45:316:56
1813.45:326:55
1913.45:336:54
2013.35:336:52
2113.35:346:51
2213.25:356:50
2313.25:366:48
2413.25:376:47
2513.15:386:45
2613.15:396:44
2713.05:406:42
2813.05:406:41
2913.05:416:39
3012.95:426:38
3112.95:436:36

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 6.73 kWh/m².

For context, solar energy here swings from a low near 2.19 kWh/m² to a high of 7.72 kWh/m² in June across the year — August's 6.73 kWh/m² falls in the middle.

02468151015202531
Solar energy (kWh/m²)Level
17.1Intense
27.1Intense
37.0Intense
47.0Intense
57.0Intense
67.0Intense
77.0Intense
86.9Intense
96.9Intense
106.9Intense
116.9Intense
126.8Intense
136.8Intense
146.8Intense
156.8Intense
166.7Intense
176.7Intense
186.7Intense
196.7Intense
206.6Intense
216.6Intense
226.6Intense
236.5Intense
246.5Intense
256.5Intense
266.5Intense
276.4Intense
286.4Intense
296.4Intense
306.3Intense
316.3Intense
Planning a trip in August

Hazard calendar for San Bruno

In seasonPeak

None of San Bruno's seasonal hazards are active in August. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

San Bruno's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit San Bruno?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.9
Sightseeing
2nd-best month of the year
3.3
Beach & pool
2nd-best month of the year

August is one of the better times to visit San Bruno for general sightseeing.

What to pack for San Bruno in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, San Bruno sees daytime highs around 66°F and nights near 56°F. Pack sun protection.

sun protection

Sea temperature near San Bruno in August

The nearest coast averages about 58°F in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 12 mi away) is warmest in September at about 58°F and coldest in April near 53°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

52°54°56°58°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan53Bracing
Feb54Bracing
Mar54Bracing
Apr53Bracing
May53Bracing
Jun54Bracing
Jul56Bracing
Aug58Bracing
Sep58Bracing
Oct57Bracing
Nov56Bracing
Dec54Bracing

UV index in San Bruno in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Bruno peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 15UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in San Bruno in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in San Bruno is worst in August — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (June, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 1824 µg/m³Jun 1110 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar16Moderate
Apr12Moderate
May10Good
Jun10Good
Jul11Good
Aug25Moderate
Sep17Moderate
Oct20Moderate
Nov18Moderate
Dec13Moderate
Location & terrain

Where is San Bruno?

San Bruno sits at 37.6°N, 122.4°W, 16 ft above sea level, in United States. The nearest listed city is South San Francisco, 1.9 mi away.

Topography around San Bruno

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Bruno.

Within 2 miles, the terrain around San Bruno has only modest variations in elevation — a maximum elevation change of 604 ft around an average of 102 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 1,991 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.

The land around San Bruno is covered by artificial surfaces (72%) within 2 miles, water (48%), trees (23%) and artificial surfaces (23%) within 10 miles, and water (42%), trees (22%) and grassland (21%) within 50 miles.

2 miles
604 ft
10 miles
1,991 ft
50 miles
4,452 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
August weather nearby: South San Francisco 1.9 mi · Millbrae 2.5 mi · Burlingame 4.3 mi · Pacifica 4.3 mi · Daly City 5.6 mi · Visitacion Valley 6.2 mi · San Mateo 6.8 mi · Bayview-Hunters Point 6.8 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Bruno (37.6305°, -122.4111°, elevation 16 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).