| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -4.9° | -13.8° | 62.5mm | 10.5 | 9 |
| February | -2.6° | -13.3° | 50.8mm | 8.9 | 12 |
| March | 3.2° | -6.8° | 59.2mm | 9 | 15 |
| April | 11.6° | 0.8° | 80mm | 9.5 | 52 |
| May | 19.9° | 8.3° | 80.6mm | 10 | 80 |
| June | 24.6° | 13.6° | 93.2mm | 10.7 | 79 |
| July | 26.8° | 16.3° | 95.6mm | 10.4 | 79 |
| August | 25.8° | 15.2° | 90.9mm | 8.6 | 83 |
| September | 21.3° | 10.9° | 92.4mm | 9 | 82 |
| October | 13.7° | 4.7° | 102.7mm | 10.6 | 59 |
| November | 6.2° | -1.8° | 76.3mm | 10 | 30 |
| December | -0.9° | -8.5° | 76.6mm | 10.9 | 8 |
January in Saint-Louis-de-Terrebonne averages a daily high of -4.9°C with nights around -13.8°C. Expect roughly 10.5 wet days totalling 62.5mm. A hard month to visit for comfort alone.
February in Saint-Louis-de-Terrebonne averages a daily high of -2.6°C with nights around -13.3°C. Expect roughly 8.9 wet days totalling 50.8mm. A hard month to visit for comfort alone.
March in Saint-Louis-de-Terrebonne averages a daily high of 3.2°C with nights around -6.8°C. Expect roughly 9 wet days totalling 59.2mm. A hard month to visit for comfort alone.
April in Saint-Louis-de-Terrebonne averages a daily high of 11.6°C with nights around 0.8°C. Expect roughly 9.5 wet days totalling 80mm. Demanding conditions — pack for it and plan indoor options.
May in Saint-Louis-de-Terrebonne averages a daily high of 19.9°C with nights around 8.3°C. Expect roughly 10 wet days totalling 80.6mm. Comfortable conditions for being outdoors all day.
June in Saint-Louis-de-Terrebonne averages a daily high of 24.6°C with nights around 13.6°C. Expect roughly 10.7 wet days totalling 93.2mm. Comfortable conditions for being outdoors all day.
July in Saint-Louis-de-Terrebonne averages a daily high of 26.8°C with nights around 16.3°C. Expect roughly 10.4 wet days totalling 95.6mm. Comfortable conditions for being outdoors all day.
August in Saint-Louis-de-Terrebonne averages a daily high of 25.8°C with nights around 15.2°C. Expect roughly 8.6 wet days totalling 90.9mm. Comfortable conditions for being outdoors all day.
September in Saint-Louis-de-Terrebonne averages a daily high of 21.3°C with nights around 10.9°C. Expect roughly 9 wet days totalling 92.4mm. Comfortable conditions for being outdoors all day.
October in Saint-Louis-de-Terrebonne averages a daily high of 13.7°C with nights around 4.7°C. Expect roughly 10.6 wet days totalling 102.7mm. Generally workable, with some weather to plan around.
November in Saint-Louis-de-Terrebonne averages a daily high of 6.2°C with nights around -1.8°C. Expect roughly 10 wet days totalling 76.3mm. A hard month to visit for comfort alone.
December in Saint-Louis-de-Terrebonne averages a daily high of -0.9°C with nights around -8.5°C. Expect roughly 10.9 wet days totalling 76.6mm. A hard month to visit for comfort alone.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Saint-Louis-de-Terrebonne peaks at 83.
Based on 30 years of records, May–September scores highest for comfort in Saint-Louis-de-Terrebonne, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 26.8°C.
October is the wettest, averaging 102.7mm of rain across roughly 10.6 wet days.
January is the coolest month, with average daily highs around -4.9°C.