Climate averages 1991–2020

Vallejo weather
in July.

A hot, very dry month: the 2nd warmest and the driest of the year. Meets the pleasant-weather rule

Long-term climate patterns, not a forecast for a particular trip.

Average high 28.5°C Daytime mean, July

Average low 13.4°C Night-time mean, July

Rainfall <1 mm Almost no rain

Daylight 15 h Sunrise to sunset, per day

July is a hot month in Vallejo: daytime highs average 28.5°C and nights cool to about 13.4°C. By daytime temperature it is the 2nd warmest of the 12 months.

Rain is very rare: less than 1 mm falls in a typical July (the driest month of the year). Daylight, from sunrise to sunset, lasts about 14 h 32 min on an average July day.

The nearest other city in this atlas is Napa (22 km away). In July its highs average 30.7°C, 2.2°C warmer than Vallejo, with almost no rain (under 1 mm).

Among the 498 cities listed in the United States, Vallejo ranks joint 332nd of 498 for the warmest July highs and joint 21st of 498 for the driest July (rainfall, lowest first). The mean July high of those 498 cities is 30.3°C; Vallejo is 1.8°C cooler than that mean.

From July to August, average highs rise by 0.2°C to 28.6°C, and monthly rainfall stays under 1 mm.

The annual picture

July in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Vallejo climate table

1991–2020

Monthly climate averages for Vallejo, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	14.0°C5.1°C	5.1°C	101	9.3	9.810 h
February	15.6°C6.1°C	6.1°C	107	8.9	10.811 h
March	17.7°C7.3°C	7.3°C	80	8.7	11.912 h
April	20.3°C8.5°C	8.5°C	37	4.9	13.213 h
May	23.7°C10.7°C	10.7°C	19	3.0	14.214 h
June	27.4°C12.6°C	12.6°C	4.2	0.8	14.815 h
July, selected	28.5°C13.4°C	13.4°C	0.5	0.1	14.515 h
August	28.6°C13.8°C	13.8°C	0.9	0.2	13.614 h
September	28.2°C13.5°C	13.5°C	1.8	0.4	12.512 h
October	24.4°C11.9°C	11.9°C	23	3.0	11.211 h
November	18.0°C8.3°C	8.3°C	49	5.6	10.210 h
December	13.9°C5.5°C	5.5°C	95	9.3	9.610 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

July in nearby cities

Distance from Vallejo

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Vallejo) is explained once on the Vallejo year overview and on the Sources, method and limits page.