Climate averages 1991–2020

Oshawa weather
in May.

A mild, moderately wet month: the 5th warmest and the 6th driest of the year.

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

Average high 16.1°C Daytime mean, May
Average low 8.6°C Night-time mean, May
Rainfall 76 mm 11 days with ≥1 mm
Daylight 15 h Sunrise to sunset, per day
Every month in Oshawa · average highYear overview

May is a mild month in Oshawa: daytime highs average 16.1°C and nights cool to about 8.6°C. By daytime temperature it is the 5th warmest of the 12 months.

Expect about 76 mm of rain on roughly 11 days, which makes May a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 43 min on an average May day.

The nearest other city in this atlas is Whitby (7 km away). In May its highs average 16.4°C, about as warm as Oshawa, with 80 mm of rain.

Among the 86 cities listed in Canada, Oshawa ranks joint 66th of 86 for the warmest May highs and 24th of 86 for the driest May (rainfall, lowest first). The mean May high of those 86 cities is 17.0°C; Oshawa is 0.9°C cooler than that mean.

From May to June, average highs rise by 5.6°C to 21.7°C, and monthly rainfall rises from 76 mm to 89 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. -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, selected 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 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

May 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.