The highest day temperature in September 2026 was 80°F. The lowest night temperature was 43°F. The average values for day and night temperatures during September were 72.1°F и 57.4°F respectivly.

The average sea surface temperature in September 2026 for Oshawa was 68.4°F. The maximum and minimum values were 61.2°F and 72.6°F respectively.

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation total in September for Oshawa is 1.3 in. It makes september one of the most rainy months of the year.

The average wind speed in September is 8.3 mph. It makes September one of the most windless months of the year for Oshawa.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Oshawa in September is 7.7 hours.