| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 0.2° | -6° | — | — | 27 |
| February | 0.9° | -5.8° | — | — | 27 |
| March | 4.9° | -1.7° | — | — | 40 |
| April | 10.5° | 3.4° | — | — | 64 |
| May | 16.8° | 9° | — | — | 84 |
| June | 22.6° | 15.2° | — | — | 94 |
| July | 25.6° | 18.3° | — | — | 94 |
| August | 25° | 18.2° | — | — | 94 |
| September | 21.5° | 14.7° | — | — | 94 |
| October | 14.9° | 8.4° | — | — | 78 |
| November | 8.5° | 2.7° | — | — | 57 |
| December | 3.1° | -2.3° | — | — | 33 |
January in Hamilton averages a daily high of 0.2°C with nights around -6°C. A hard month to visit for comfort alone.
February in Hamilton averages a daily high of 0.9°C with nights around -5.8°C. A hard month to visit for comfort alone.
March in Hamilton averages a daily high of 4.9°C with nights around -1.7°C. Demanding conditions — pack for it and plan indoor options.
April in Hamilton averages a daily high of 10.5°C with nights around 3.4°C. Generally workable, with some weather to plan around.
May in Hamilton averages a daily high of 16.8°C with nights around 9°C. Comfortable conditions for being outdoors all day.
June in Hamilton averages a daily high of 22.6°C with nights around 15.2°C. Comfortable conditions for being outdoors all day.
July in Hamilton averages a daily high of 25.6°C with nights around 18.3°C. Comfortable conditions for being outdoors all day.
August in Hamilton averages a daily high of 25°C with nights around 18.2°C. Comfortable conditions for being outdoors all day.
September in Hamilton averages a daily high of 21.5°C with nights around 14.7°C. Comfortable conditions for being outdoors all day.
October in Hamilton averages a daily high of 14.9°C with nights around 8.4°C. Comfortable conditions for being outdoors all day.
November in Hamilton averages a daily high of 8.5°C with nights around 2.7°C. Generally workable, with some weather to plan around.
December in Hamilton averages a daily high of 3.1°C with nights around -2.3°C. 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 94.
Based on 30 years of records, June–September scores highest for comfort in Hamilton, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25.6°C.
January is the wettest, averaging —mm of rain across roughly — wet days.
January is the coolest month, with average daily highs around 0.2°C.