Climate averages 1991–2020

Vallejo weather
in April.

A mild, fairly dry month: the 7th warmest and the 7th driest of the year. Meets the pleasant-weather rule

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

Average high 20.3°C Daytime mean, April
Average low 8.5°C Night-time mean, April
Rainfall 37 mm 5 days with ≥1 mm
Daylight 13 h Sunrise to sunset, per day
Every month in Vallejo · average highYear overview

April is a mild month in Vallejo: daytime highs average 20.3°C and nights cool to about 8.5°C. By daytime temperature it is the 7th warmest of the 12 months.

Expect about 37 mm of rain on roughly 5 days, which makes April a fairly dry month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 10 min on an average April day.

The nearest other city in this atlas is Napa (22 km away). In April its highs average 20.7°C, about as warm as Vallejo, with 38 mm of rain.

Among the 498 cities listed in the United States, Vallejo ranks joint 237th of 498 for the warmest April highs and joint 116th of 498 for the driest April (rainfall, lowest first). The mean April high of those 498 cities is 19.4°C; Vallejo is 0.9°C warmer than that mean.

From April to May, average highs rise by 3.5°C to 23.7°C, and monthly rainfall falls from 37 mm to 19 mm.

The annual picture

April in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. 05101520253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 1500

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
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 14.0°C5.1°C5.1°C1019.39.810 h
February 15.6°C6.1°C6.1°C1078.910.811 h
March 17.7°C7.3°C7.3°C808.711.912 h
April, selected 20.3°C8.5°C8.5°C374.913.213 h
May 23.7°C10.7°C10.7°C193.014.214 h
June 27.4°C12.6°C12.6°C4.20.814.815 h
July 28.5°C13.4°C13.4°C0.50.114.515 h
August 28.6°C13.8°C13.8°C0.90.213.614 h
September 28.2°C13.5°C13.5°C1.80.412.512 h
October 24.4°C11.9°C11.9°C233.011.211 h
November 18.0°C8.3°C8.3°C495.610.210 h
December 13.9°C5.5°C5.5°C959.39.610 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

April 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.