| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -4.3° | -12.9° | 88.5mm | 16.7 | 0 |
| February | -3.1° | -11.7° | 72.8mm | 13.8 | 2 |
| March | 2.6° | -6.2° | 78.4mm | 12.9 | 7 |
| April | 10.8° | 1° | 94.4mm | 12.3 | 44 |
| May | 18.8° | 8.1° | 98.2mm | 12.8 | 71 |
| June | 23.6° | 13.3° | 110.9mm | 13.8 | 72 |
| July | 25.7° | 16° | 114.5mm | 13.5 | 73 |
| August | 24.9° | 15° | 115.8mm | 12 | 76 |
| September | 20.6° | 10.8° | 113mm | 11.7 | 77 |
| October | 13° | 4.8° | 113.5mm | 13.4 | 51 |
| November | 6° | -1.3° | 90mm | 14.6 | 21 |
| December | -0.6° | -7.9° | 103.5mm | 17.1 | 0 |
January in Granby averages a daily high of -4.3°C with nights around -12.9°C. Expect roughly 16.7 wet days totalling 88.5mm. A hard month to visit for comfort alone.
February in Granby averages a daily high of -3.1°C with nights around -11.7°C. Expect roughly 13.8 wet days totalling 72.8mm. A hard month to visit for comfort alone.
March in Granby averages a daily high of 2.6°C with nights around -6.2°C. Expect roughly 12.9 wet days totalling 78.4mm. A hard month to visit for comfort alone.
April in Granby averages a daily high of 10.8°C with nights around 1°C. Expect roughly 12.3 wet days totalling 94.4mm. Demanding conditions — pack for it and plan indoor options.
May in Granby averages a daily high of 18.8°C with nights around 8.1°C. Expect roughly 12.8 wet days totalling 98.2mm. Generally workable, with some weather to plan around.
June in Granby averages a daily high of 23.6°C with nights around 13.3°C. Expect roughly 13.8 wet days totalling 110.9mm. Generally workable, with some weather to plan around.
July in Granby averages a daily high of 25.7°C with nights around 16°C. Expect roughly 13.5 wet days totalling 114.5mm. Generally workable, with some weather to plan around.
August in Granby averages a daily high of 24.9°C with nights around 15°C. Expect roughly 12 wet days totalling 115.8mm. Comfortable conditions for being outdoors all day.
September in Granby averages a daily high of 20.6°C with nights around 10.8°C. Expect roughly 11.7 wet days totalling 113mm. Comfortable conditions for being outdoors all day.
October in Granby averages a daily high of 13°C with nights around 4.8°C. Expect roughly 13.4 wet days totalling 113.5mm. Demanding conditions — pack for it and plan indoor options.
November in Granby averages a daily high of 6°C with nights around -1.3°C. Expect roughly 14.6 wet days totalling 90mm. A hard month to visit for comfort alone.
December in Granby averages a daily high of -0.6°C with nights around -7.9°C. Expect roughly 17.1 wet days totalling 103.5mm. 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. Granby peaks at 77.
Based on 30 years of records, May–September scores highest for comfort in Granby, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25.7°C.
August is the wettest, averaging 115.8mm of rain across roughly 12 wet days.
January is the coolest month, with average daily highs around -4.3°C.