Weather in Greater Sudbury in May

A good month. May is a solid month to be in Greater Sudbury. Highs average 16.5 °C, lows 4.3 °C, and rain falls on 12 days — nothing in the month is working against you.

May ranks 5 of 12 in Greater Sudbury: past the worst of the year but short of July, which is the month to book if the dates are open.

Rain on 12 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 16.5 °C days and 4.3 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 6 nights fall below freezing. Across the twenty years measured, the hottest May day reached 30.1 °C and the coldest night fell to -5.3 °C, and the wettest single day dropped 43 mm — roughly 58% of the month's rain in one day.

May is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest May on record still delivered 124 mm against 19 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 74 mm average is a reasonable planning figure, not a promise.

Wind is light at 2.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How May sits in the year

The month is on the way up: 8.1 °C warmer than April, and June adds another 5.4 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in May

15 hours of daylight, gaining 1.2 hours across the month. That is between Greater Sudbury's extremes of 15.8 and 8.6 hours, so days are long enough not to constrain the plan.

An inland climate

Greater Sudbury has no sea to moderate it, and it shows: 43.2 °C separates the hottest afternoon of the year from the coldest night. That is a genuinely continental range, and it means summer and winter here are barely the same place.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

May in Greater Sudbury versus nearby

If Greater Sudbury is one option among several, the nearby comparison is worth making. Barrie is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Peterborough is a better bet in May — 2.9 °C warmer, 1 day less rain.

So: May works, with July the better month by 11 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Greater Sudbury

See all twelve months in Greater Sudbury, or where else to go in May.