Saint John
September
Weather in Saint John for September 2025
Your guide to Saint John weather in September - trends and predictions
In general, the average temperature in Saint John at the beginning of September is 20.4 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 17.6 °C by the end of September.
The climate of Saint John in September is notably wet, with an average of 13 rainy days, and a total of 134.5 mm of precipitation.
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Temperatures
Rain 🌧️
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17
Dry days
13
Rainy days
0
Snow days
18°/11°
Temperatures
15 km/h
Avg max wind
82 %
Avg humidity
Saint John in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  19° | 2  20° | 3 19° | 4  20° | 5 23° | 6 22° | 7 20° |
| 8  18° | 9 17° | 10 19° | 11  18° | 12 19° | 13 19° | 14  19° |
| 15 19° | 16 20° | 17 19° | 18  16° | 19  18° | 20 17° | 21 18° |
| 22 16° | 23 15° | 24 18° | 25 17° | 26 16° | 27 18° | 28 18° |
| 29 17° | 30 19° |
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Temperatures trend during September in Saint John
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Sunny | 19° /10° | 10.8 mm | 5 | |
| 2 Sept. | Overcast | 20° /11° | 0.8 mm | 5 | |
| 3 Sept. | Overcast | 19° /10° | 0 mm | 5 | |
| 4 Sept. | Fog | 20° /11° | 0 mm | 5 | |
| 5 Sept. | Fog | 23° /13° | 0 mm | 6 | |
| 6 Sept. | Overcast | 22° /12° | 0 mm | 5 | |
| 7 Sept. | Mist | 20° /14° | 0.6 mm | 5 | |
| 8 Sept. | Light rain shower | 18° /11° | 4.3 mm | 5 | |
| 9 Sept. | Fog | 17° /10° | 3.5 mm | 5 | |
| 10 Sept. | Light rain shower | 19° /11° | 7.2 mm | 4 | |
| 11 Sept. | Moderate or heavy rain shower | 18° /10° | 12.1 mm | 5 | |
| 12 Sept. | Fog | 19° /12° | 0 mm | 5 | |
| 13 Sept. | Fog | 19° /12° | 3.3 mm | 5 | |
| 14 Sept. | Heavy rain | 19° /12° | 5.4 mm | 5 | |
| 15 Sept. | Overcast | 19° /8° | 0 mm | 5 | |
| 16 Sept. | Light rain shower | 20° /12° | 33.8 mm | 5 | |
| 17 Sept. | Overcast | 19° /12° | 4.9 mm | 5 | |
| 18 Sept. | Light drizzle | 16° /11° | 1.8 mm | 4 | |
| 19 Sept. | Moderate rain | 18° /12° | 3.8 mm | 4 | |
| 20 Sept. | Patchy rain possible | 17° /13° | 0 mm | 4 | |
| 21 Sept. | Mist | 18° /10° | 0 mm | 4 | |
| 22 Sept. | Sunny | 16° /8° | 0 mm | 5 | |
| 23 Sept. | Overcast | 15° /9° | 0 mm | 4 | |
| 24 Sept. | Mist | 18° /10° | 0 mm | 5 | |
| 25 Sept. | Patchy rain possible | 17° /10° | 0.1 mm | 4 | |
| 26 Sept. | Sunny | 16° /7° | 4.9 mm | 4 | |
| 27 Sept. | Sunny | 18° /9° | 37.1 mm | 5 | |
| 28 Sept. | Mist | 18° /8° | 0 mm | 5 | |
| 29 Sept. | Fog | 17° /9° | 0 mm | 4 | |
| 30 Sept. | Mist | 19° /9° | 0 mm | 4 | |
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Important Notice
Our weather forecast for Saint John in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Saint John forecast closer to your planned date for the most up-to-date weather information.
Saint John in September - FAQ
What are the expected maximum and minimum temperatures in Saint John during September?
Enjoy moderate daytime temperatures of up to 18° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Saint John during September?
Significant rainfall exceeding 134.5 mm is expected in Saint John during September, occurring over more than 13 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Saint John during September?
The average wind speed in Saint John during September is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Saint John
Explore the daily rainfall trends and prepare for Saint Johns September weather 💧
UV exposure in Saint John during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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