Climate averages 1991–2020

Kennewick weather
in May.

A warm, fairly dry month: the 5th warmest and the 6th driest of the year. Meets the pleasant-weather rule

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

Average high 24.8°C Daytime mean, May
Average low 11.4°C Night-time mean, May
Rainfall 18 mm 5 days with ≥1 mm
Daylight 15 h Sunrise to sunset, per day
Every month in Kennewick · average highYear overview

May is a warm month in Kennewick: daytime highs average 24.8°C and nights cool to about 11.4°C. By daytime temperature it is the 5th warmest of the 12 months.

Expect about 18 mm of rain on roughly 5 days, which makes May a fairly dry month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 57 min on an average May day.

The nearest other city in this atlas is Tri-Cities (6 km away). In May its highs average 25.0°C, about as warm as Kennewick, with 18 mm of rain.

Among the 498 cities listed in the United States, Kennewick ranks joint 206th of 498 for the warmest May highs and joint 96th of 498 for the driest May (rainfall, lowest first). The mean May high of those 498 cities is 23.8°C; Kennewick is 1.0°C warmer than that mean.

From May to June, average highs rise by 3.9°C to 28.8°C, and monthly rainfall falls from 18 mm to 13 mm.

The annual picture

May 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. -50510152025303540 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 500

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

Every month, side by side

Kennewick climate table

1991–2020
Monthly climate averages for Kennewick, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 5.7°C-1.7°C-1.7°C348.19.19 h
February 9.1°C-0.5°C-0.5°C236.210.310 h
March 14.2°C2.7°C2.7°C245.911.912 h
April 19.1°C6.5°C6.5°C174.913.514 h
May, selected 24.8°C11.4°C11.4°C184.514.915 h
June 28.8°C15.2°C15.2°C132.815.716 h
July 34.1°C19.1°C19.1°C3.81.015.415 h
August 33.0°C18.5°C18.5°C4.21.014.214 h
September 27.4°C13.9°C13.9°C6.91.812.613 h
October 18.7°C7.8°C7.8°C225.011.011 h
November 10.5°C2.2°C2.2°C297.39.59 h
December 5.4°C-1.4°C-1.4°C358.48.79 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

May in nearby cities

Distance from Kennewick

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 Kennewick) is explained once on the Kennewick year overview and on the Sources, method and limits page.

Tri-Cities lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.