| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.4° | -4.2° | 84.1mm | 10.7 | 19 |
| February | 6.3° | -3.2° | 71.6mm | 10.1 | 28 |
| March | 11° | 0.7° | 98.8mm | 11.1 | 47 |
| April | 17.3° | 5.8° | 97.6mm | 11.6 | 68 |
| May | 22.6° | 11.1° | 99.9mm | 12 | 76 |
| June | 27.4° | 16.3° | 108mm | 11.7 | 75 |
| July | 30.3° | 19.5° | 109.9mm | 10.7 | 65 |
| August | 29.1° | 18.6° | 110.8mm | 10.3 | 71 |
| September | 25.4° | 14.5° | 105.7mm | 8.5 | 83 |
| October | 18.9° | 8.2° | 95.4mm | 9.7 | 77 |
| November | 12.9° | 2.5° | 77.1mm | 8.4 | 60 |
| December | 7.2° | -1.3° | 101.4mm | 11.1 | 32 |
January in Trenton averages a daily high of 4.4°C with nights around -4.2°C. Expect roughly 10.7 wet days totalling 84.1mm. A hard month to visit for comfort alone.
February in Trenton averages a daily high of 6.3°C with nights around -3.2°C. Expect roughly 10.1 wet days totalling 71.6mm. A hard month to visit for comfort alone.
March in Trenton averages a daily high of 11°C with nights around 0.7°C. Expect roughly 11.1 wet days totalling 98.8mm. Demanding conditions — pack for it and plan indoor options.
April in Trenton averages a daily high of 17.3°C with nights around 5.8°C. Expect roughly 11.6 wet days totalling 97.6mm. Generally workable, with some weather to plan around.
May in Trenton averages a daily high of 22.6°C with nights around 11.1°C. Expect roughly 12 wet days totalling 99.9mm. Comfortable conditions for being outdoors all day.
June in Trenton averages a daily high of 27.4°C with nights around 16.3°C. Expect roughly 11.7 wet days totalling 108mm. Comfortable conditions for being outdoors all day.
July in Trenton averages a daily high of 30.3°C with nights around 19.5°C. Expect roughly 10.7 wet days totalling 109.9mm. Generally workable, with some weather to plan around.
August in Trenton averages a daily high of 29.1°C with nights around 18.6°C. Expect roughly 10.3 wet days totalling 110.8mm. Generally workable, with some weather to plan around.
September in Trenton averages a daily high of 25.4°C with nights around 14.5°C. Expect roughly 8.5 wet days totalling 105.7mm. Comfortable conditions for being outdoors all day.
October in Trenton averages a daily high of 18.9°C with nights around 8.2°C. Expect roughly 9.7 wet days totalling 95.4mm. Comfortable conditions for being outdoors all day.
November in Trenton averages a daily high of 12.9°C with nights around 2.5°C. Expect roughly 8.4 wet days totalling 77.1mm. Generally workable, with some weather to plan around.
December in Trenton averages a daily high of 7.2°C with nights around -1.3°C. Expect roughly 11.1 wet days totalling 101.4mm. 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. Trenton peaks at 83.
Based on 30 years of records, May–June scores highest for comfort in Trenton, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 30.3°C.
August is the wettest, averaging 110.8mm of rain across roughly 10.3 wet days.
January is the coolest month, with average daily highs around 4.4°C.