| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.4° | -5.5° | 72.4mm | 10.9 | 17 |
| February | 6.8° | -4.6° | 66.6mm | 10.3 | 27 |
| March | 12.6° | 0.2° | 97.2mm | 11.9 | 50 |
| April | 19.3° | 5.5° | 111.9mm | 13.2 | 71 |
| May | 24.4° | 11.4° | 109.3mm | 14.5 | 71 |
| June | 28.5° | 15.9° | 102.8mm | 12.7 | 69 |
| July | 30.3° | 18.1° | 95.1mm | 12.6 | 62 |
| August | 30° | 16.9° | 68.6mm | 10.4 | 67 |
| September | 26.9° | 12.5° | 84.2mm | 10.9 | 78 |
| October | 20° | 5.9° | 77.3mm | 10.1 | 80 |
| November | 12.9° | 0.1° | 71.6mm | 9.7 | 55 |
| December | 6.7° | -3.3° | 87.5mm | 12.7 | 24 |
January in Hamilton averages a daily high of 4.4°C with nights around -5.5°C. Expect roughly 10.9 wet days totalling 72.4mm. A hard month to visit for comfort alone.
February in Hamilton averages a daily high of 6.8°C with nights around -4.6°C. Expect roughly 10.3 wet days totalling 66.6mm. A hard month to visit for comfort alone.
March in Hamilton averages a daily high of 12.6°C with nights around 0.2°C. Expect roughly 11.9 wet days totalling 97.2mm. Demanding conditions — pack for it and plan indoor options.
April in Hamilton averages a daily high of 19.3°C with nights around 5.5°C. Expect roughly 13.2 wet days totalling 111.9mm. Generally workable, with some weather to plan around.
May in Hamilton averages a daily high of 24.4°C with nights around 11.4°C. Expect roughly 14.5 wet days totalling 109.3mm. Generally workable, with some weather to plan around.
June in Hamilton averages a daily high of 28.5°C with nights around 15.9°C. Expect roughly 12.7 wet days totalling 102.8mm. Generally workable, with some weather to plan around.
July in Hamilton averages a daily high of 30.3°C with nights around 18.1°C. Expect roughly 12.6 wet days totalling 95.1mm. Generally workable, with some weather to plan around.
August in Hamilton averages a daily high of 30°C with nights around 16.9°C. Expect roughly 10.4 wet days totalling 68.6mm. Generally workable, with some weather to plan around.
September in Hamilton averages a daily high of 26.9°C with nights around 12.5°C. Expect roughly 10.9 wet days totalling 84.2mm. Comfortable conditions for being outdoors all day.
October in Hamilton averages a daily high of 20°C with nights around 5.9°C. Expect roughly 10.1 wet days totalling 77.3mm. Comfortable conditions for being outdoors all day.
November in Hamilton averages a daily high of 12.9°C with nights around 0.1°C. Expect roughly 9.7 wet days totalling 71.6mm. Generally workable, with some weather to plan around.
December in Hamilton averages a daily high of 6.7°C with nights around -3.3°C. Expect roughly 12.7 wet days totalling 87.5mm. 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. Hamilton peaks at 80.
Based on 30 years of records, September–October scores highest for comfort in Hamilton, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 30.3°C.
April is the wettest, averaging 111.9mm of rain across roughly 13.2 wet days.
January is the coolest month, with average daily highs around 4.4°C.