| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -4.8° | -14° | 70.8mm | 13.4 | 3 |
| February | -3.4° | -13.1° | 55.9mm | 10.8 | 8 |
| March | 2.7° | -6.5° | 63.1mm | 11.5 | 9 |
| April | 11.1° | 0.8° | 85.1mm | 12 | 46 |
| May | 19.8° | 7.9° | 87.5mm | 12.6 | 74 |
| June | 24.3° | 13.3° | 97mm | 13.3 | 73 |
| July | 26.3° | 15.3° | 114.7mm | 13.1 | 74 |
| August | 25.5° | 14.5° | 101.2mm | 11.8 | 76 |
| September | 21.5° | 10.2° | 87.4mm | 10.5 | 79 |
| October | 13.8° | 4.5° | 108.2mm | 13.7 | 53 |
| November | 6.1° | -1.7° | 79.7mm | 12.8 | 24 |
| December | -0.4° | -8.2° | 86.4mm | 13.8 | 2 |
January in Saint-Hyacinthe averages a daily high of -4.8°C with nights around -14°C. Expect roughly 13.4 wet days totalling 70.8mm. A hard month to visit for comfort alone.
February in Saint-Hyacinthe averages a daily high of -3.4°C with nights around -13.1°C. Expect roughly 10.8 wet days totalling 55.9mm. A hard month to visit for comfort alone.
March in Saint-Hyacinthe averages a daily high of 2.7°C with nights around -6.5°C. Expect roughly 11.5 wet days totalling 63.1mm. A hard month to visit for comfort alone.
April in Saint-Hyacinthe averages a daily high of 11.1°C with nights around 0.8°C. Expect roughly 12 wet days totalling 85.1mm. Demanding conditions — pack for it and plan indoor options.
May in Saint-Hyacinthe averages a daily high of 19.8°C with nights around 7.9°C. Expect roughly 12.6 wet days totalling 87.5mm. Generally workable, with some weather to plan around.
June in Saint-Hyacinthe averages a daily high of 24.3°C with nights around 13.3°C. Expect roughly 13.3 wet days totalling 97mm. Generally workable, with some weather to plan around.
July in Saint-Hyacinthe averages a daily high of 26.3°C with nights around 15.3°C. Expect roughly 13.1 wet days totalling 114.7mm. Generally workable, with some weather to plan around.
August in Saint-Hyacinthe averages a daily high of 25.5°C with nights around 14.5°C. Expect roughly 11.8 wet days totalling 101.2mm. Comfortable conditions for being outdoors all day.
September in Saint-Hyacinthe averages a daily high of 21.5°C with nights around 10.2°C. Expect roughly 10.5 wet days totalling 87.4mm. Comfortable conditions for being outdoors all day.
October in Saint-Hyacinthe averages a daily high of 13.8°C with nights around 4.5°C. Expect roughly 13.7 wet days totalling 108.2mm. Demanding conditions — pack for it and plan indoor options.
November in Saint-Hyacinthe averages a daily high of 6.1°C with nights around -1.7°C. Expect roughly 12.8 wet days totalling 79.7mm. A hard month to visit for comfort alone.
December in Saint-Hyacinthe averages a daily high of -0.4°C with nights around -8.2°C. Expect roughly 13.8 wet days totalling 86.4mm. 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-Hyacinthe peaks at 79.
Based on 30 years of records, May–September scores highest for comfort in Saint-Hyacinthe, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 26.3°C.
July is the wettest, averaging 114.7mm of rain across roughly 13.1 wet days.
January is the coolest month, with average daily highs around -4.8°C.