Click on a day for an hourly weather forecast
The temperatures in Ontario in October are comfortable with low of 17°C and and high up to 26°C.
You can expect a few rainy days in Ontario during October, but usually the weather is comfortable in October.
Our weather forecast can give you a great sense of what weather to expect in Ontario in October 2025.
If you’re planning to visit Ontario in the near future, we highly recommend that you review the 14 day weather forecast for Ontario before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 19° / 9° | 2 | 29 | 0 | 57 mm | Good | Ontario in January |
| February | 19° / 9° | 2 | 26 | 0 | 63 mm | Good | Ontario in February |
| March | 20° / 10° | 2 | 29 | 0 | 36 mm | Good | Ontario in March |
| April | 22° / 12° | 1 | 29 | 0 | 22 mm | Good | Ontario in April |
| May | 24° / 14° | 0 | 31 | 0 | 7 mm | Perfect | Ontario in May |
| June | 28° / 18° | 0 | 30 | 0 | 1 mm | Perfect | Ontario in June |
| July | 31° / 21° | 0 | 31 | 0 | 10 mm | Good | Ontario in July |
| August | 32° / 22° | 0 | 31 | 0 | 6 mm | Good | Ontario in August |
| September | 31° / 21° | 0 | 30 | 0 | 5 mm | Good | Ontario in September |
| October | 26° / 17° | 1 | 30 | 0 | 10 mm | Perfect | Ontario in October |
| November | 22° / 12° | 1 | 29 | 0 | 22 mm | Good | Ontario in November |
| December | 18° / 9° | 3 | 28 | 0 | 72 mm | Good | Ontario in December |