Typically, you can expect that the weather in Niagara Falls in May is 12 with the high being 20 degrees with a low of 8. We have put some more information below:
| Month | Degrees Celsius |
|---|---|
| Temperature | 12 |
| High Temperature | 20 |
| Low Temperature | 8 |
Useful Links: Niagara Falls Weather: Average Weather & Yearly Climate