Climate averages 1991–2020

Oshawa weather
in August.

A warm, moderately wet month: the 2nd warmest and the joint 7th driest of the year.

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

Average high 24.6°C Daytime mean, August
Average low 17.9°C Night-time mean, August
Rainfall 80 mm 10 days with ≥1 mm
Daylight 14 h Sunrise to sunset, per day
Every month in Oshawa · average highYear overview

August is a warm month in Oshawa: daytime highs average 24.6°C and nights cool to about 17.9°C. By daytime temperature it is the 2nd warmest of the 12 months.

Expect about 80 mm of rain on roughly 10 days, which makes August a moderately wet month (the joint 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 00 min on an average August day.

The nearest other city in this atlas is Whitby (7 km away). In August its highs average 24.8°C, about as warm as Oshawa, with 85 mm of rain.

Among the 86 cities listed in Canada, Oshawa ranks joint 26th of 86 for the warmest August highs and joint 50th of 86 for the driest August (rainfall, lowest first). The mean August high of those 86 cities is 23.8°C; Oshawa is 0.8°C warmer than that mean.

From August to September, average highs fall by 3.8°C to 20.8°C, and monthly rainfall stays at 80 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. -15-10-5051015202530 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly precipitation

Average total · mm
Average monthly precipitation totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 1000

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

Every month, side by side

Oshawa climate table

1991–2020
Monthly climate averages for Oshawa, 1991–2020
MonthAverage highHigh / lowAverage lowPrecipitation mm/monthWet days ≥1 mm/dayDaylight hours/dayDay­light h/day
January -1.5°C-8.4°C-8.4°C6510.79.39 h
February -1.2°C-8.5°C-8.5°C528.310.410 h
March 3.2°C-4.1°C-4.1°C6010.411.912 h
April 9.6°C2.1°C2.1°C8311.213.413 h
May 16.1°C8.6°C8.6°C7611.014.715 h
June 21.7°C14.6°C14.6°C8911.015.415 h
July 25.1°C18.1°C18.1°C8410.515.115 h
August, selected 24.6°C17.9°C17.9°C8010.114.014 h
September 20.8°C14.4°C14.4°C809.012.613 h
October 13.9°C8.1°C8.1°C8311.411.011 h
November 7.1°C1.9°C1.9°C7310.29.710 h
December 1.8°C-3.8°C-3.8°C6710.79.09 h

Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet 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 Oshawa

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