St. John's Weather in September
St. John's in September sees moderate temperatures, with highs around 17°C (63°F) and overnight lows of 10°C (50°F). Rainfall is fairly high at around 103 mm (4.1 in) on average, so pack waterproofs just in case.
Rainfall in St. John's in September
Historically, approximately 14 days this month are expected to have rain, averaging 103 mm (4.1 in). The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in St. John's in September
September in St. John's brings moderate temperatures, with highs of 17°C (63°F) and nights around 10°C (50°F). The month of September belongs to the summer season. Temperatures can feel cooler in the morning and evening, so layering is often the best approach. With overnight lows of 10°C (50°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.
Sunshine in St. John's in September
With about 170 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.Should you favor a climate that's both dry and comfortably warm, August typically offers the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Canada, check out our St. John's's climate page.
St. John's Temperature in September
Min Temperature
10°C (50°F)
Max Temperature
17°C (63°F)
Chance of Rain
48%
Precipitation
103 mm (4.1 in)
Rainy days
14 days
Sunshine
170 hours
Percentage Sunshine
45%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in St. John's typically drop from around 18°C (64°F) at the start of September to approximately 15°C (59°F) by the end. Nights are cool, with lows typically ranging from 7°C (45°F) to 11°C (52°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for St. John's in September
Browse day-by-day weather records for St. John's spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
St. John's historical weather extremes in September
Based on 49 years of weather observations in St. John's between 1976 and 2025, these are the recorded extremes.
- The warmest day in September was on September 10, 2001, with a maximum of 29°C (84°F).
- On September 28, 1989, St. John's saw its coldest September day with temperatures maxing out at 7°C (45°F).
- The coldest night in September in St. John's was on September 26, 2018, with a minimum of 0°C (32°F).
Best Places in Canada in September
Find out more about the weather in Canada and which places have the best travel conditions in this month. See all of Canada in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in St. John's in September
For St. John's in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in St. John's in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Canada, check out our St. John's's climate page.
See the full St. John's climate overview or explore weather in Canada.
