San Luis Obispo weather in August

In August, San Luis Obispo sees average daytime highs of 72°F and overnight lows near 59°F, with 0.0 in of rain across 0.1 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 72°F through the month. The sky is clear or mostly clear about 91% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 13 h 48 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is San Luis Obispo's 1st-clearest and 11th-windiest month. For the whole year in context, see San Luis Obispo's year-round climate.

Daytime high
72°
1st warmest
Overnight low
59°
12th coldest
Rainfall
0.0 in
0.1 wet days
Daylight
13 h 18 min
5:27 AM – 6:47 PM
Cloud cover
14%
1st clearest
Wind
5 mph
11th windiest
Solar energy
7.29 kWh/m²
Travel score
9.2
out of 10

San Luis Obispo is county seat of San Luis Obispo County, California, United States.

Density
1,414/km²
people per km²
Founded
1772

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 72°F through the month.

A typical August day in San Luis Obispo reaches about 72°F in the afternoon and slips back to 59°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 67°F and 79°F. Set against its neighbours, August runs about 1°F warmer than July and on par with September.

50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17259
27259
37259
47259
57259
67259
77259
87259
97259
107259
117259
127259
137259
147259
157259
167259
177259
187259
197259
207259
217259
227359
237359
247359
257359
267359
277359
287359
297359
307359
317359

San Luis Obispo weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan60° / 47°3.97.29.95.2
Feb60° / 48°3.77.610.75.1
Mar61° / 49°2.86.211.75.8
Apr63° / 51°1.03.412.96.9
May65° / 53°0.41.513.87.8
Jun69° / 56°0.10.414.38.6
Jul71° / 58°0.00.114.19.0
Aug72° / 59°0.00.113.39.2
Sep72° / 59°0.00.412.29.1
Oct70° / 56°0.8211.18.5
Nov64° / 51°1.33.610.17.1
Dec60° / 47°3.06.69.75.3

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 91% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 5% of August, with mostly cloudy or overcast conditions the remaining 4%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1946
2955
3955
4964
5964
6964
7964
8964
9964
10964
11964
12964
13964
14964
15964
16964
17964
18973
19973
20973
21973
22973
23973
24973
25973
26973
27973
28973
29973
30973
31973

Chance of precipitation in August

Any precipitation

San Luis Obispo gets around 0.0 in of rain over 0.1 wet days in August, the driest month. 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
210
220
230
241
251
261
271
281
291
301
311

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the comfortable band about 71% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11672111
21672111
31672111
41574110
51574110
61573120
71573120
81573120
91573120
101573120
111573120
121573120
131573120
141573120
151573120
161573120
171573120
181573120
191573120
201573120
211573120
221672120
231671130
241671130
251769140
261769140
271769140
281867150
291866151
301965151
312064151

Wind in August

Winds average 5 mph in August.

Across August, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 48 min at the start of August to 12 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over August. Sunrise moves from 5:15 AM to 5:38 AM, and sunset from 7:03 PM to 6:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.85:157:03
213.85:167:02
313.75:167:01
413.75:177:00
513.75:186:59
613.75:196:58
713.65:196:57
813.65:206:56
913.65:216:55
1013.55:226:54
1113.55:236:53
1213.55:236:52
1313.45:246:50
1413.45:256:49
1513.45:266:48
1613.35:276:47
1713.35:276:46
1813.35:286:45
1913.25:296:43
2013.25:306:42
2113.25:306:41
2213.15:316:39
2313.15:326:38
2413.15:336:37
2513.05:346:35
2613.05:346:34
2713.05:356:33
2812.95:366:31
2912.95:376:30
3012.95:376:29
3112.85:386:27

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 7.29 kWh/m².

For context, solar energy here swings from a low near 2.76 kWh/m² to a high of 8.19 kWh/m² in June across the year — August's 7.29 kWh/m² falls in the middle.

02468151015202531
Solar energy (kWh/m²)Level
17.7Intense
27.6Intense
37.6Intense
47.6Intense
57.6Intense
67.5Intense
77.5Intense
87.5Intense
97.5Intense
107.5Intense
117.4Intense
127.4Intense
137.4Intense
147.3Intense
157.3Intense
167.3Intense
177.3Intense
187.2Intense
197.2Intense
207.2Intense
217.1Intense
227.1Intense
237.1Intense
247.0Intense
257.0Intense
267.0Intense
277.0Intense
286.9Intense
296.9Intense
306.8Intense
316.8Intense
Planning a trip in August

Is August a good time to visit San Luis Obispo?

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

9.2
Sightseeing
1st-best month of the year
6.6
Beach & pool
1st-best month of the year

August is one of the better times to visit San Luis Obispo for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for San Luis Obispo in August

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

In August, San Luis Obispo sees daytime highs around 72°F and nights near 59°F. Pack sun protection. Worth having: light clothes.

sun protectionlight clothes

Sea temperature near San Luis Obispo in August

The nearest coast averages about 59°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 11 mi away) is warmest in September at about 60°F and coldest in April near 54°F.

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

52°54°56°58°60°62°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan56Bracing
Feb56Bracing
Mar55Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul58Bracing
Aug59Cool
Sep60Cool
Oct60Cool
Nov58Bracing
Dec57Bracing

UV index in San Luis Obispo 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 Luis Obispo peaks around June 22 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 22UV 11Dec 15UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun11Extreme
Jul10Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in San Luis Obispo 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 Luis Obispo is worst in August — around 19 µg/m³ PM2.5 (moderate), about 4.5× the cleanest month (June, 4 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 2218 µg/m³Jun 124 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb6Good
Mar7Good
Apr6Good
May5Good
Jun4Good
Jul7Good
Aug19Moderate
Sep17Moderate
Oct7Good
Nov6Good
Dec5Good
Location & terrain

Where is San Luis Obispo?

San Luis Obispo sits at 35.3°N, 120.7°W, 233 ft above sea level, in United States. The nearest listed city is Arroyo Grande, 12 mi away.

Topography around San Luis Obispo

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

Within 2 miles, the terrain around San Luis Obispo has significant variations in elevation — a maximum elevation change of 1,572 ft around an average of 420 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,861 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,407 ft.

The land around San Luis Obispo is covered by grassland (39%), artificial surfaces (36%) and trees (20%) within 2 miles, grassland (44%) and trees (41%) within 10 miles, and grassland (50%) and water (25%) within 50 miles.

2 miles
1,572 ft
10 miles
2,861 ft
50 miles
5,407 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Arroyo Grande 12 mi · Atascadero 14 mi · Nipomo 19 mi · Paso Robles 24 mi · Santa Maria 26 mi · Orcutt 32 mi · Lompoc 46 mi · Coalinga 62 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 Luis Obispo (35.2828°, -120.6596°, elevation 233 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).