St. Johns climate
St. Johns (Newfoundland and Labrador, Canada) has a subarctic climate (Köppen Dfc). The average temperature over the year is 5 °C42 °F, and about 1,300 mm51 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
St. Johns climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 032 | −425 | −229 | 1275.0 | 28 |
| Feb | −131 | −424 | −327 | 1054.1 | 28 |
| Mar | 032 | −326 | −229 | 1174.6 | 28 |
| Apr | 337 | −131 | 134 | 903.5 | 19 |
| May | 642 | 236 | 439 | 903.5 | 2 |
| Jun | 1050 | 643 | 846 | 863.4 | 0 |
| Jul | 1660 | 1253 | 1456 | 933.7 | 0 |
| Aug | 1763 | 1457 | 1660 | 903.5 | 0 |
| Sep | 1559 | 1152 | 1355 | 1044.1 | 0 |
| Oct | 1051 | 745 | 948 | 1315.1 | 0 |
| Nov | 643 | 337 | 440 | 1285.0 | 4 |
| Dec | 236 | −130 | 133 | 1405.5 | 18 |
| Year | 1763 | −424 | 542 | 1,30051 | 126 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 87% | 83% | 1.0 | 8:50 |
| Feb | 87% | 81% | 1.7 | 10:11 |
| Mar | 87% | 80% | 2.8 | 11:45 |
| Apr | 88% | 77% | 4.0 | 13:34 |
| May | 90% | 77% | 4.8 | 15:06 |
| Jun | 90% | 77% | 5.0 | 15:57 |
| Jul | 90% | 73% | 5.0 | 15:36 |
| Aug | 88% | 72% | 4.3 | 14:15 |
| Sep | 86% | 69% | 3.4 | 12:29 |
| Oct | 87% | 74% | 2.1 | 10:45 |
| Nov | 86% | 77% | 1.2 | 9:13 |
| Dec | 87% | 82% | 0.8 | 8:27 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of St. Johns is like
The warmest month is August, with an average high of 17 °C63 °F and a low of 14 °C57 °F. The coldest is February, when highs average −1 °C31 °F and lows −4 °C24 °F. Seasons are strongly marked: the warmest month is on average 18.2 °C32.8 °F warmer than the coldest.
It is wet, with about 1,300 mm51 in of precipitation per year. Rain is spread fairly evenly through the year. The wettest month is December (140 mm5.5 in), the driest is June (86 mm3.4 in).
Relative humidity ranges from 86% in September to 90% in June. The clearest skies (lowest average cloud amount, 69%) are typical of September. Average wind speed near the ground ranges from 13 km/h (8 mph) in July to 23 km/h (14 mph) in February. Daylight lasts from about 8.4 hours in December to 16.0 hours in June.
A lasting snow cover is typical in December–April. In those months the average snow depth in the reanalysis exceeds 10 cm. It is deepest in January, at about 19 cm.
Best time to visit St. Johns
Based on these averages, the most comfortable months for sightseeing and outdoor activities are August. Average highs then reach 17 °C63 °F to 17 °C63 °F. Precipitation is 90 mm3.5 in to 90 mm3.5 in per month.
The most challenging month is January, which is cold, with average highs of 0 °C32 °F.
Comfort score: months are ranked by how close they come to an ideal. That means an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for St. Johns
- Winter (December–February) — highs −131 to 2 °C36 °F, lows −424 to −1 °C30 °F, about 124 mm4.9 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots, shoes with good grip, as frost is common and an umbrella or light rain jacket.
- Spring (March–May) — highs 032 to 6 °C42 °F, lows −326 to 2 °C36 °F, about 99 mm3.9 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots, shoes with good grip, as frost is common and an umbrella or light rain jacket.
- Summer (June–August) — highs 1050 to 17 °C63 °F, lows 643 to 14 °C57 °F, about 90 mm3.5 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
- Autumn (September–November) — highs 643 to 15 °C59 °F, lows 337 to 11 °C52 °F, about 121 mm4.8 in of precipitation a month. Pack a warm coat, layers and closed shoes and an umbrella or light rain jacket.
How St. Johns compares
World Climates covers 40 places in Canada. By annual mean temperature, St. Johns is the 28th warmest of them. By annual precipitation, it is the 5th wettest. See all of them on the Canada climate page.
Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Saint-Pierre (Saint Pierre and Miquelon, Dfc), Trondheim (Norway, Dfb) and Reykjavík (Iceland, Cfc).
Nearby places
- Climate in Saint-Pierre 276 km · 6 °C43 °F · 1,176 mm46 in
- Climate in Sydney 590 km · 7 °C44 °F · 1,224 mm48 in
- Climate in Halifax 898 km · 7 °C45 °F · 1,300 mm51 in
- Climate in Saguenay 1,366 km · 3 °C38 °F · 972 mm38 in
- Climate in Québec 1,398 km · 5 °C41 °F · 1,146 mm45 in
- Climate in Sherbrooke 1,485 km · 6 °C42 °F · 1,135 mm45 in
Frequently asked questions
What is the warmest month in St. Johns?
August is the warmest month in St. Johns. Its average high is 17 °C (63 °F) and its average low is 14 °C (57 °F).
What is the coldest month in St. Johns?
February is the coldest month. Its average high is -1 °C (31 °F) and its average low is -4 °C (24 °F).
When does it rain the most in St. Johns?
December is the wettest month with about 140 mm (5.5 in) of precipitation. June is the driest with about 86 mm (3.4 in).
What is the best time to visit St. Johns?
Judging by long-term averages, the most comfortable months are August.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station. So they can differ from airport records. The gaps are largest on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.