Last Frost Date Sarnia: Frost Dates, Late Frost Risk & Growing Season

When is the last spring frost and the first autumn frost in Sarnia? Frost dates from 30 years of data, the risk of late frost, frost-free days and planting dates.

The frost season in Sarnia

Last frost (average): April 28
In 1 year out of 10 it still freezes on May 13.
First frost: November 4
Frost-free season: 187 days
Frost after 15 May: in 3 % of years

Frost days per month in Sarnia

January: 29.1 · -8 °C
February: 27.1 · -8 °C
March: 25.6 · -4 °C
April: 11.6 · 1 °C
May: 0.5 · 7 °C
June: 0 · 13 °C
July: 0 · 17 °C
August: 0 · 16 °C
September: 0 · 13 °C
October: 1 · 6 °C
November: 13.8 · 1 °C
December: 27.1 · -4 °C

No weather station nearby: plain grid values, which are often a little too cold – dates may therefore be late.
Daily minimum temperatures 2 m above ground over 30 years (1991–2020), NASA POWER; station data: Deutscher Wetterdienst (CC BY 4.0). Ground frost can form while the air at 2 m is still +2 to +3 °C.