| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -0.7° | -8.1° | 73.2mm | 12.5 | 5 |
| February | 0.3° | -7.3° | 54.3mm | 9.6 | 12 |
| March | 4.7° | -3.2° | 51.2mm | 9.8 | 24 |
| April | 10.7° | 2.1° | 81mm | 11 | 48 |
| May | 17.6° | 8° | 87.8mm | 11.3 | 70 |
| June | 22.7° | 13.6° | 94.1mm | 11.4 | 77 |
| July | 25.7° | 16.4° | 90.7mm | 10 | 80 |
| August | 25.1° | 16.1° | 70.1mm | 9.5 | 81 |
| September | 21.3° | 12.3° | 86.8mm | 9.9 | 80 |
| October | 14.1° | 6.2° | 81.1mm | 13.2 | 55 |
| November | 7.8° | 1.1° | 74.1mm | 11.7 | 36 |
| December | 2.5° | -3.8° | 67.6mm | 12.2 | 12 |
January in Ajax averages a daily high of -0.7°C with nights around -8.1°C. Expect roughly 12.5 wet days totalling 73.2mm. A hard month to visit for comfort alone.
February in Ajax averages a daily high of 0.3°C with nights around -7.3°C. Expect roughly 9.6 wet days totalling 54.3mm. A hard month to visit for comfort alone.
March in Ajax averages a daily high of 4.7°C with nights around -3.2°C. Expect roughly 9.8 wet days totalling 51.2mm. A hard month to visit for comfort alone.
April in Ajax averages a daily high of 10.7°C with nights around 2.1°C. Expect roughly 11 wet days totalling 81mm. Demanding conditions — pack for it and plan indoor options.
May in Ajax averages a daily high of 17.6°C with nights around 8°C. Expect roughly 11.3 wet days totalling 87.8mm. Generally workable, with some weather to plan around.
June in Ajax averages a daily high of 22.7°C with nights around 13.6°C. Expect roughly 11.4 wet days totalling 94.1mm. Comfortable conditions for being outdoors all day.
July in Ajax averages a daily high of 25.7°C with nights around 16.4°C. Expect roughly 10 wet days totalling 90.7mm. Comfortable conditions for being outdoors all day.
August in Ajax averages a daily high of 25.1°C with nights around 16.1°C. Expect roughly 9.5 wet days totalling 70.1mm. Comfortable conditions for being outdoors all day.
September in Ajax averages a daily high of 21.3°C with nights around 12.3°C. Expect roughly 9.9 wet days totalling 86.8mm. Comfortable conditions for being outdoors all day.
October in Ajax averages a daily high of 14.1°C with nights around 6.2°C. Expect roughly 13.2 wet days totalling 81.1mm. Generally workable, with some weather to plan around.
November in Ajax averages a daily high of 7.8°C with nights around 1.1°C. Expect roughly 11.7 wet days totalling 74.1mm. Demanding conditions — pack for it and plan indoor options.
December in Ajax averages a daily high of 2.5°C with nights around -3.8°C. Expect roughly 12.2 wet days totalling 67.6mm. 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. Ajax peaks at 81.
Based on 30 years of records, June–September scores highest for comfort in Ajax, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25.7°C.
June is the wettest, averaging 94.1mm of rain across roughly 11.4 wet days.
January is the coolest month, with average daily highs around -0.7°C.