Climate averages 1991–2020
Saint-Louis-de-Terrebonne weather
in September.
A mild, wet month: the 4th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Saint-Louis-de-Terrebonne: daytime highs average 20.0°C and nights cool to about 11.9°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 94 mm of rain on roughly 10 days, which makes September a wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 35 min on an average September day.
The nearest other city in this atlas is Terrebonne (11 km away). In September its highs average 20.3°C, about as warm as Saint-Louis-de-Terrebonne, with 94 mm of rain.
Among the 86 cities listed in Canada, Saint-Louis-de-Terrebonne ranks joint 48th of 86 for the warmest September highs and joint 58th of 86 for the driest September (rainfall, lowest first). The mean September high of those 86 cities is 19.8°C; Saint-Louis-de-Terrebonne is 0.2°C warmer than that mean.
From September to October, average highs fall by 7.6°C to 12.4°C, and monthly rainfall rises from 94 mm to 107 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Saint-Louis-de-Terrebonne climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -5.7°C-15.1°C | -15.1°C | 76 | 10.2 | 9.19 h |
| February | -3.7°C-13.4°C | -13.4°C | 62 | 8.8 | 10.310 h |
| March | 2.1°C-7.5°C | -7.5°C | 74 | 10.4 | 11.912 h |
| April | 10.1°C0.2°C | 0.2°C | 103 | 11.3 | 13.513 h |
| May | 18.1°C7.9°C | 7.9°C | 95 | 11.4 | 14.915 h |
| June | 23.0°C13.9°C | 13.9°C | 101 | 11.7 | 15.616 h |
| July | 25.3°C16.8°C | 16.8°C | 95 | 12.3 | 15.315 h |
| August | 24.2°C16.0°C | 16.0°C | 96 | 11.6 | 14.114 h |
| September, selected | 20.0°C11.9°C | 11.9°C | 94 | 10.0 | 12.613 h |
| October | 12.4°C5.4°C | 5.4°C | 107 | 11.4 | 11.011 h |
| November | 5.0°C-1.4°C | -1.4°C | 87 | 11.1 | 9.510 h |
| December | -1.9°C-9.6°C | -9.6°C | 86 | 11.6 | 8.89 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Terrebonne in SeptemberCanada · 11 kmHigh 20.3°C · Low 12.2°C · 94 mm rain
- Laval in SeptemberCanada · 16 kmHigh 20.4°C · Low 12.2°C · 92 mm rain
- Villeray–Saint-Michel–Parc-Extension in SeptemberCanada · 21 kmHigh 20.3°C · Low 11.9°C · 99 mm rain
- Pierrefonds-Roxboro in SeptemberCanada · 23 kmHigh 20.4°C · Low 12.6°C · 92 mm rain
- Mercier–Hochelaga-Maisonneuve in SeptemberCanada · 24 kmHigh 20.4°C · Low 12.3°C · 99 mm rain
- Montréal in SeptemberCanada · 26 kmHigh 19.3°C · Low 11.3°C · 99 mm rain
- Repentigny in SeptemberCanada · 27 kmHigh 20.3°C · Low 12.1°C · 95 mm rain
- Longueuil in SeptemberCanada · 32 kmHigh 20.4°C · Low 12.3°C · 99 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Saint-Louis-de-Terrebonne) is explained once on the Saint-Louis-de-Terrebonne year overview and on the Sources, method and limits page.
Terrebonne lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.