Click on a day for an hourly weather forecast
The temperatures in Saint Catharines in May are quite cold with temperatures between 9°C and 16°C, warm clothes are a must.
You can expect rain for roughly half of the month of May in Saint Catharines. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Saint Catharines in May 2025.
If you’re planning to visit Saint Catharines in the near future, we highly recommend that you review the 14 day weather forecast for Saint Catharines before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -6° | 8 | 7 | 18 | 102 mm | Awful | Saint Catharines in January |
| February | -1° / -6° | 7 | 5 | 17 | 109 mm | Awful | Saint Catharines in February |
| March | 4° / -2° | 10 | 11 | 10 | 114 mm | Awful | Saint Catharines in March |
| April | 10° / 3° | 9 | 17 | 4 | 139 mm | Awful | Saint Catharines in April |
| May | 16° / 9° | 8 | 23 | 0 | 147 mm | Ok | Saint Catharines in May |
| June | 21° / 14° | 7 | 23 | 0 | 158 mm | Ok | Saint Catharines in June |
| July | 25° / 18° | 8 | 23 | 0 | 156 mm | Good | Saint Catharines in July |
| August | 25° / 19° | 7 | 24 | 0 | 148 mm | Good | Saint Catharines in August |
| September | 22° / 15° | 6 | 24 | 0 | 113 mm | Good | Saint Catharines in September |
| October | 15° / 10° | 9 | 22 | 1 | 135 mm | Ok | Saint Catharines in October |
| November | 8° / 3° | 8 | 16 | 6 | 95 mm | Awful | Saint Catharines in November |
| December | 2° / -1° | 9 | 8 | 15 | 109 mm | Awful | Saint Catharines in December |