Climate and weather averages
What St. John's's weather is normally like, month by month, from the official Environment Canada climate normals.
A climate normal is a thirty-year average, not a forecast and not last year. Comparing a normal against today’s weather is how you tell whether a day is unusual for the time of year. This page uses the 1981-2010 normals for ST JOHN'S A (St. John's International Airport).
The year at a glance
Month by month
| Month | Mean °C | Daily high °C | Daily low °C | Rain mm | Snow cm | Precip mm |
|---|---|---|---|---|---|---|
| January | -4.5 | -0.8 | -8.2 | 66 | 89 | 149 |
| February | -4.9 | -1.1 | -8.6 | 62 | 71 | 130 |
| March | -2.6 | 1.0 | -6.1 | 85 | 57 | 142 |
| April | 1.9 | 5.5 | -1.9 | 96 | 25 | 123 |
| May | 6.4 | 11.1 | 1.7 | 98 | 4 | 103 |
| June | 10.9 | 15.8 | 5.9 | 98 | 0 | 98 |
| July | 15.8 | 20.7 | 10.9 | 92 | 0 | 92 |
| August | 16.1 | 20.5 | 11.6 | 100 | 0 | 100 |
| September | 12.3 | 16.5 | 8.2 | 130 | 0 | 130 |
| October | 7.4 | 10.8 | 3.9 | 154 | 2 | 156 |
| November | 3.0 | 6.4 | -0.3 | 125 | 22 | 148 |
| December | -1.5 | 1.8 | -4.7 | 103 | 63 | 165 |
The same station records an average of 1,633 hours of bright sunshine a year, and 212 days a year with measurable precipitation. Sunshine is measured with a recorder rather than estimated from cloud cover, which is why some stations — Halifax among them — do not publish it.
Frost and the growing season
The frost-free period averages 139 days a year at this station. The last frost of spring falls around day 150 of the year and the first frost of autumn around day 290. Days are counted from 1 January.
Official sources
- Canadian Climate Normals 1981-2010 — ST JOHN'S A
- Environment Canada — current conditions and forecast
Details such as fares, fees, hours and program rules change. Always confirm against the official source before acting on anything time-sensitive.