Click on a day for an hourly weather forecast
The temperatures in Oshawa in August are comfortable with low of 17°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Oshawa during the month of August. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Oshawa in August 2025.
If you’re planning to visit Oshawa in the near future, we highly recommend that you review the 14 day weather forecast for Oshawa before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -9° | 7 | 5 | 19 | 94 mm | Awful | Oshawa in January |
| February | -3° / -8° | 6 | 5 | 17 | 85 mm | Awful | Oshawa in February |
| March | 3° / -3° | 7 | 13 | 11 | 92 mm | Awful | Oshawa in March |
| April | 9° / 2° | 9 | 16 | 5 | 129 mm | Awful | Oshawa in April |
| May | 16° / 8° | 7 | 24 | 0 | 134 mm | Ok | Oshawa in May |
| June | 21° / 13° | 8 | 22 | 0 | 154 mm | Ok | Oshawa in June |
| July | 25° / 17° | 8 | 23 | 0 | 160 mm | Good | Oshawa in July |
| August | 24° / 17° | 7 | 24 | 0 | 154 mm | Good | Oshawa in August |
| September | 21° / 14° | 6 | 24 | 0 | 117 mm | Good | Oshawa in September |
| October | 14° / 8° | 8 | 22 | 1 | 126 mm | Ok | Oshawa in October |
| November | 7° / 2° | 8 | 15 | 7 | 81 mm | Awful | Oshawa in November |
| December | 1° / -3° | 9 | 8 | 14 | 87 mm | Awful | Oshawa in December |