| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -1.3° | -10.4° | 66.9mm | 12.5 | 5 |
| February | 0° | -9.7° | 53.8mm | 10.8 | 8 |
| March | 4.9° | -4.7° | 57.3mm | 11.3 | 19 |
| April | 11.9° | 2.1° | 80.8mm | 11.8 | 50 |
| May | 19.4° | 8.8° | 76.1mm | 11.5 | 75 |
| June | 24.5° | 14.6° | 89.7mm | 11.1 | 78 |
| July | 27.2° | 17.2° | 81mm | 10.7 | 78 |
| August | 26.5° | 16.4° | 73mm | 9.8 | 80 |
| September | 22.5° | 12.3° | 87.9mm | 10 | 80 |
| October | 14.8° | 6.2° | 87.6mm | 12.9 | 58 |
| November | 7.6° | -0.3° | 80.5mm | 11.8 | 33 |
| December | 1.9° | -5.6° | 70.5mm | 13.2 | 7 |
January in Belleville averages a daily high of -1.3°C with nights around -10.4°C. Expect roughly 12.5 wet days totalling 66.9mm. A hard month to visit for comfort alone.
February in Belleville averages a daily high of 0°C with nights around -9.7°C. Expect roughly 10.8 wet days totalling 53.8mm. A hard month to visit for comfort alone.
March in Belleville averages a daily high of 4.9°C with nights around -4.7°C. Expect roughly 11.3 wet days totalling 57.3mm. A hard month to visit for comfort alone.
April in Belleville averages a daily high of 11.9°C with nights around 2.1°C. Expect roughly 11.8 wet days totalling 80.8mm. Demanding conditions — pack for it and plan indoor options.
May in Belleville averages a daily high of 19.4°C with nights around 8.8°C. Expect roughly 11.5 wet days totalling 76.1mm. Comfortable conditions for being outdoors all day.
June in Belleville averages a daily high of 24.5°C with nights around 14.6°C. Expect roughly 11.1 wet days totalling 89.7mm. Comfortable conditions for being outdoors all day.
July in Belleville averages a daily high of 27.2°C with nights around 17.2°C. Expect roughly 10.7 wet days totalling 81mm. Comfortable conditions for being outdoors all day.
August in Belleville averages a daily high of 26.5°C with nights around 16.4°C. Expect roughly 9.8 wet days totalling 73mm. Comfortable conditions for being outdoors all day.
September in Belleville averages a daily high of 22.5°C with nights around 12.3°C. Expect roughly 10 wet days totalling 87.9mm. Comfortable conditions for being outdoors all day.
October in Belleville averages a daily high of 14.8°C with nights around 6.2°C. Expect roughly 12.9 wet days totalling 87.6mm. Generally workable, with some weather to plan around.
November in Belleville averages a daily high of 7.6°C with nights around -0.3°C. Expect roughly 11.8 wet days totalling 80.5mm. A hard month to visit for comfort alone.
December in Belleville averages a daily high of 1.9°C with nights around -5.6°C. Expect roughly 13.2 wet days totalling 70.5mm. 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. Belleville peaks at 80.
Based on 30 years of records, May–September scores highest for comfort in Belleville, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 27.2°C.
June is the wettest, averaging 89.7mm of rain across roughly 11.1 wet days.
January is the coolest month, with average daily highs around -1.3°C.