Petaluma weather in July

In July, Petaluma sees average daytime highs of 75°F and overnight lows near 55°F, with 0.0 in of rain across 0.1 wet days and about 14.4 hours of daylight. It is the 2nd-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 75°F through the month. The sky is clear or mostly clear about 89% of the time in July, and the air most often feels dry.

Daylight stretches from about 14 h 36 min at the start of July to 14 hours by month's end. Set against the rest of the year, July is Petaluma's 1st-clearest and 6th-windiest month. For the whole year in context, see Petaluma's year-round climate.

Daytime high
75°
2nd warmest
Overnight low
55°
11th coldest
Rainfall
0.0 in
0.1 wet days
Daylight
14 h 24 min
5:04 AM – 7:29 PM
Cloud cover
19%
1st clearest
Wind
5 mph
6th windiest
Solar energy
7.78 kWh/m²
Travel score
9.5
out of 10

Petaluma is city in Sonoma County, California, United States.

Density
1,611/km²
people per km²
Founded
1858

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

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 75°F through the month.

A typical July day in Petaluma reaches about 75°F in the afternoon and slips back to 55°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 68°F and 82°F. Set against its neighbours, July runs about 2°F warmer than June and on par with August.

50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17555
27555
37555
47555
57555
67555
77555
87555
97555
107555
117555
127555
137555
147555
157555
167555
177555
187555
197555
207555
217555
227555
237555
247555
257555
267555
277555
287555
297555
307555
317555

Petaluma weather by month

How July compares with the rest of the year at a glance. July is the 2nd-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan56° / 42°5.410.39.63.9
Feb59° / 43°5.69.310.54.5
Mar61° / 45°4.29.311.75.3
Apr64° / 47°1.95.6136.5
May68° / 50°1.03.3147.7
Jun73° / 53°0.2114.69.0
Jul75° / 55°0.00.114.49.5
Aug75° / 55°0.00.213.59.5
Sep75° / 54°0.10.512.39.3
Oct71° / 51°1.23.1118.2
Nov62° / 45°2.86.29.95.9
Dec56° / 42°5.510.49.43.9

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 89% of the time in July, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 6% of July, with mostly cloudy or overcast conditions the remaining 5%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1937
2937
3937
4955
5955
6955
7964
8964
9964
10964
11964
12964
13964
14955
15955
16955
17955
18955
19955
20955
21946
22946
23946
24946
25946
26946
27946
28946
29946
30946
31937

Chance of precipitation in July

Any precipitation

Petaluma gets around 0.0 in of rain over 0.1 wet days in July, 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 (%)
11
21
31
41
51
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the dry band about 73% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
183170
283170
382180
482180
581190
681190
780200
879210
979210
1078220
1177230
1276240
1375250
1474260
1573270
1672280
1770291
1869301
1968311
2068311
2168311
2268311
2368311
2468311
2568311
2668311
2768311
2868311
2968320
3068320
3168320

Wind in July

Winds average 5 mph in July.

Across July, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in July

DaylightNight

Daylight runs from about 14 h 36 min at the start of July to 14 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 36 minutes over July. Sunrise moves from 4:55 AM to 5:16 AM, and sunset from 7:33 PM to 7:18 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.64:557:33
214.64:557:33
314.64:567:33
414.64:567:33
514.64:577:32
614.64:577:32
714.64:587:32
814.64:587:32
914.54:597:31
1014.55:007:31
1114.55:007:31
1214.55:017:30
1314.55:027:30
1414.55:027:30
1514.45:037:29
1614.45:047:29
1714.45:047:28
1814.45:057:28
1914.45:067:27
2014.35:077:26
2114.35:077:26
2214.35:087:25
2314.35:097:24
2414.25:107:24
2514.25:117:23
2614.25:117:22
2714.25:127:21
2814.15:137:20
2914.15:147:20
3014.15:157:19
3114.05:167:18

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 7.78 kWh/m².

For context, solar energy here swings from a low near 2.11 kWh/m² to a high of 7.93 kWh/m² in June across the year — July's 7.78 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
18.0Intense
28.0Intense
38.0Intense
48.0Intense
58.0Intense
68.0Intense
78.0Intense
87.9Intense
97.9Intense
107.9Intense
117.9Intense
127.9Intense
137.8Intense
147.8Intense
157.8Intense
167.8Intense
177.7Intense
187.7Intense
197.7Intense
207.7Intense
217.7Intense
227.6Intense
237.6Intense
247.6Intense
257.6Intense
267.5Intense
277.5Intense
287.5Intense
297.5Intense
307.5Intense
317.4Intense
Planning a trip in July

Hazard calendar for Petaluma

In seasonPeak

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

Petaluma'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 July a good time to visit Petaluma?

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

9.5
Sightseeing
1st-best month of the year
7.8
Beach & pool
2nd-best month of the year

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

What to pack for Petaluma in July

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

In July, Petaluma sees daytime highs around 75°F and nights near 55°F. Pack sun protection. Worth having: light clothes.

sun protectionlight clothes

Sea temperature near Petaluma in July

The nearest coast averages about 56°F in July — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 25 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 Petaluma in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July 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 Petaluma peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 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 17UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Low

Air quality in Petaluma in July

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Petaluma is worst in September — around 24 µg/m³ PM2.5 (moderate), about 4.1× the cleanest month (June, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1623 µg/m³Jun 116 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar9Good
Apr7Good
May7Good
Jun6Good
Jul9Good
Aug17Moderate
Sep24Moderate
Oct16Moderate
Nov9Good
Dec7Good
Location & terrain

Where is Petaluma?

Petaluma sits at 38.2°N, 122.6°W, 30 ft above sea level, in United States. The nearest listed city is Rohnert Park, 8.1 mi away.

Topography around Petaluma

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

Within 2 miles, the terrain around Petaluma has only modest variations in elevation — a maximum elevation change of 548 ft around an average of 121 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,464 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,915 ft.

The land around Petaluma is covered by artificial surfaces (43%), grassland (31%) and trees (22%) within 2 miles, grassland (55%) and trees (26%) within 10 miles, and water (33%), trees (31%) and grassland (24%) within 50 miles.

2 miles
548 ft
10 miles
2,464 ft
50 miles
4,915 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
July weather nearby: Rohnert Park 8.1 mi · Novato 9.3 mi · Agua Caliente 11 mi · Santa Rosa 15 mi · San Rafael 19 mi · Napa 19 mi · American Canyon 21 mi · Vallejo 22 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 Petaluma (38.2324°, -122.6367°, elevation 30 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).