Climate averages 1991–2020

Gresham weather
in August.

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

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

Average high 26.1°C Daytime mean, August
Average low 13.9°C Night-time mean, August
Rainfall 20 mm 3 days with ≥1 mm
Daylight 14 h Sunrise to sunset, per day
Every month in Gresham · average highYear overview

August is a warm month in Gresham: daytime highs average 26.1°C and nights cool to about 13.9°C. By daytime temperature it is the warmest month of the year.

Expect about 20 mm of rain on roughly 3 days, which makes August a fairly dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 07 min on an average August day.

The nearest other city in this atlas is Portland (19 km away). In August its highs average 27.6°C, 1.5°C warmer than Gresham, with 14 mm of rain.

Among the 498 cities listed in the United States, Gresham ranks joint 437th of 498 for the warmest August highs and 137th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Gresham is 3.8°C cooler than that mean.

From August to September, average highs fall by 3.3°C to 22.8°C, and monthly rainfall rises from 20 mm to 58 mm.

The annual picture

August 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. -5051015202530 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 2500

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

Every month, side by side

Gresham climate table

1991–2020
Monthly climate averages for Gresham, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 7.5°C1.1°C1.1°C22018.39.19 h
February 9.1°C1.2°C1.2°C16715.710.310 h
March 11.5°C2.4°C2.4°C17818.211.912 h
April 14.0°C4.5°C4.5°C14216.613.513 h
May 17.8°C7.9°C7.9°C8911.614.915 h
June 20.5°C10.6°C10.6°C589.015.616 h
July 25.5°C13.6°C13.6°C142.915.315 h
August, selected 26.1°C13.9°C13.9°C202.914.114 h
September 22.8°C11.3°C11.3°C586.412.613 h
October 16.0°C7.1°C7.1°C14712.911.011 h
November 10.2°C3.4°C3.4°C23018.09.610 h
December 6.8°C1.0°C1.0°C24418.58.89 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

August in nearby cities

Distance from Gresham

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