Suisun weather in August

In August, Suisun sees average daytime highs of 85°F and overnight lows near 58°F, with 0.0 in of rain across 0.2 wet days and about 13.5 hours of daylight. It is the 1st-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 85°F through the month. The sky is clear or mostly clear about 90% 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 Suisun's 2nd-clearest and 4th-windiest month. For the whole year in context, see Suisun's year-round climate.

Daytime high
85°
1st warmest
Overnight low
58°
12th coldest
Rainfall
0.0 in
0.2 wet days
Daylight
13 h 30 min
5:27 AM – 6:57 PM
Cloud cover
10%
2nd clearest
Wind
7 mph
4th windiest
Solar energy
7.32 kWh/m²
Travel score
7.1
out of 10

Suisun is city in Solano County, California, United States.

Density
2,607/km²
people per km²
Founded
1868

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 85°F through the month.

A typical August day in Suisun reaches about 85°F in the afternoon and slips back to 58°F overnight — a 28°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 94°F. Set against its neighbours, August runs on par with July and about 2°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18558
28558
38558
48558
58558
68558
78558
88558
98558
108558
118558
128558
138558
148558
158558
168558
178558
188558
198558
208558
218558
228558
238558
248558
258558
268558
278558
288558
298558
308558
318558

Suisun weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan58° / 42°4.39.29.64.3
Feb62° / 44°4.2910.55.2
Mar66° / 46°3.18.211.76.4
Apr71° / 49°1.34.8137.5
May77° / 53°0.73.2148.4
Jun83° / 57°0.20.914.67.7
Jul85° / 58°0.00.114.47.1
Aug85° / 58°0.00.213.57.1
Sep84° / 57°0.10.412.37.7
Oct77° / 53°0.92.7118.5
Nov65° / 47°2.05.89.96.6
Dec58° / 42°3.999.44.3

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 90% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 4% of August, with mostly cloudy or overcast conditions the remaining 6%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1946
2946
3946
4946
5946
6946
7937
8937
9946
10946
11946
12946
13946
14946
15946
16946
17955
18955
19955
20955
21955
22955
23955
24955
25955
26955
27955
28955
29955
30955
31955

Chance of precipitation in August

Any precipitation

Suisun gets around 0.0 in of rain over 0.2 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 1% 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
141
151
161
171
181
191
201
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 58% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
157403
257403
357403
458402
558402
658402
758402
858402
957412
1057412
1157412
1257412
1356422
1456422
1556422
1657412
1757412
1857412
1957412
2058402
2158402
2258402
2358402
2459392
2559392
2659392
2760382
2861372
2962362
3063352
3163343

Wind in August

Winds average 7 mph in August.

Across August, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
266calm
276calm
286calm
296calm
306calm
316calm

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 5:14 AM to 5:41 AM, and sunset from 7:14 PM to 6:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:147:14
214.05:157:13
313.95:167:12
413.95:177:11
513.95:187:10
613.85:187:09
713.85:197:08
813.85:207:07
913.75:217:06
1013.75:227:05
1113.75:237:03
1213.65:247:02
1313.65:257:01
1413.65:267:00
1513.55:276:58
1613.55:276:57
1713.55:286:56
1813.45:296:54
1913.45:306:53
2013.35:316:52
2113.35:326:50
2213.35:336:49
2313.25:346:47
2413.25:356:46
2513.25:366:45
2613.15:366:43
2713.15:376:42
2813.05:386:40
2913.05:396:39
3013.05:406:37
3112.95:416:35

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 7.32 kWh/m².

For context, solar energy here swings from a low near 2.09 kWh/m² to a high of 8.13 kWh/m² in July across the year — August's 7.32 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.8Intense
27.8Intense
37.7Intense
47.7Intense
57.7Intense
67.6Intense
77.6Intense
87.6Intense
97.6Intense
107.5Intense
117.5Intense
127.5Intense
137.4Intense
147.4Intense
157.4Intense
167.3Intense
177.3Intense
187.3Intense
197.2Intense
207.2Intense
217.2Intense
227.1Intense
237.1Intense
247.0Intense
257.0Intense
267.0Intense
276.9Intense
286.9Intense
296.8Intense
306.8Intense
316.8Intense
Planning a trip in August

Hazard calendar for Suisun

In seasonPeak

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

Suisun'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 Suisun?

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

7.1
Sightseeing
6th-best month of the year
9.4
Beach & pool
2nd-best month of the year

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

What to pack for Suisun in August

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

In August, Suisun sees daytime highs around 85°F and nights near 58°F. Pack light clothes and sun protection.

light clothessun protection

Sea temperature near Suisun 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 40 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
Feb53Bracing
Mar54Bracing
Apr53Bracing
May53Bracing
Jun54Bracing
Jul56Bracing
Aug58Bracing
Sep58Bracing
Oct57Bracing
Nov55Bracing
Dec54Bracing

UV index in Suisun in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Suisun peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 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 highHighModerateJun 23UV 10Dec 13UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Suisun 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 Suisun is worst in September — around 29 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (June, 7 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateSep 1829 µg/m³Jun 127 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun7Good
Jul10Good
Aug25Moderate
Sep29Moderate
Oct27Moderate
Nov16Moderate
Dec12Good
Location & terrain

Where is Suisun?

Suisun sits at 38.2°N, 122.0°W, 7 ft above sea level, in United States. The nearest listed city is Fairfield, 0.6 mi away.

Topography around Suisun

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

Within 2 miles, the terrain around Suisun has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 16 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,382 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,459 ft.

The land around Suisun is covered by artificial surfaces (40%) and wetland (23%) within 2 miles, grassland (43%) within 10 miles, and grassland (32%) and trees (24%) within 50 miles.

2 miles
194 ft
10 miles
2,382 ft
50 miles
4,459 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
August weather nearby: Fairfield 0.6 mi · Vacaville 8.7 mi · American Canyon 13 mi · Napa 14 mi · Benicia 14 mi · Vallejo 15 mi · Bay Point 15 mi · Martinez 16 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 Suisun (38.2383°, -122.0402°, elevation 7 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).