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, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, 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 of 17 °C63 °F to 17 °C63 °F with 90 mm3.5 in to 90 mm3.5 in of precipitation 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 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
Of the 40 places in Canada covered by World Climates, St. Johns is the 28th warmest by annual mean temperature and the 5th wettest by annual precipitation. See all of them on the Canada climate page.
Places in other countries with the most similar temperature and rainfall pattern: Saint-Pierre (Saint Pierre and Miquelon, Dfc), Trondheim (Norway, Dfb) and Reykjavík (Iceland, Cfc).
Nearby places
- Saint-Pierre 276 km · 6 °C43 °F · 1,176 mm46 in
- Sydney 590 km · 7 °C44 °F · 1,224 mm48 in
- Halifax 898 km · 7 °C45 °F · 1,300 mm51 in
- Saguenay 1,366 km · 3 °C38 °F · 972 mm38 in
- Québec 1,398 km · 5 °C41 °F · 1,146 mm45 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, with an average high of 17 °C (63 °F) and an average low of 14 °C (57 °F).
What is the coldest month in St. Johns?
February is the coldest month, with an average high of -1 °C (31 °F) and an average low of -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 — most of all 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.