SeasonMapSt. John's, Newfoundland (St. John's) weather in September
Canada
September in St. John's, Newfoundland: nice, rainy, with clean air — a great time to visit.
#4 of 12 months in St. John's, Newfoundland · #795 of 1383 destinations to visit in September · comfort 77/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on St. John's, Newfoundland in September
Other months in St. John's, Newfoundland
Newfoundland's forum calls late July into August the best chance for good weather, typically around 20°C but genuinely variable — anything from a cool, wet day to full sun. Regulars are consistent that Newfoundland is rarely hot and often feels cooler than the number suggests thanks to the wind, so a rain coat and layers matter more than a summer wardrobe.
Add your own note from St. John's, Newfoundland's card on the map.
St. John's, Newfoundland climate normals — September
| Daytime high | 18°C / 65°F | 😎 nice |
|---|---|---|
| Nighttime low | 9°C / 48°F | |
| Feels like (high) | 17°C / 63°F | |
| Sea temperature | 13°C / 55°F | 🥶 cold sea |
| Rainfall | 91 mm / 3.6 in | 🌧 rainy |
| Rainy days | 10 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 11°C / 51°F | |
| Sunshine | 7.3 h/day | |
| Daylight | 12.5 h | |
| Wind | 25 km/h / 16 mph | |
| Air quality (US AQI) | 36 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in St. John's, Newfoundland in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusySummer break in Canada(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for St. John's, Newfoundland's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherSt. John's, Newfoundland's weather peaks June–August, best around July.
Best weatherFair weatherToughest weather
Where is St. John's, Newfoundland?
St. John's, Newfoundland in September — FAQ
- Is September a good time to visit St. John's, Newfoundland?
- September in St. John's, Newfoundland: nice, rainy, with clean air — a great time to visit. It ranks #4 of 12 months for St. John's, Newfoundland on SeasonMap's comfort score (77/100).
- What is the weather like in St. John's, Newfoundland in September?
- In September, St. John's, Newfoundland averages a daily high of 18.3°C and a low of 8.7°C, with about 90.9 mm of rain over roughly 10.2 rainy days.
- What is the air quality in St. John's, Newfoundland in September?
- St. John's, Newfoundland has a mean US Air Quality Index of about 36 in September.