| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 1.6° | -9.4° | 96.8mm | 9.7 | 11 |
| February | 3.3° | -8.7° | 91.8mm | 8.3 | 15 |
| March | 7.6° | -4.3° | 109.7mm | 8.8 | 33 |
| April | 14.7° | 1.4° | 113.1mm | 11.3 | 60 |
| May | 21.1° | 7.7° | 101mm | 12 | 76 |
| June | 25.7° | 13° | 106.7mm | 11.2 | 78 |
| July | 29° | 16.4° | 111.8mm | 10.9 | 70 |
| August | 28° | 15.1° | 99.8mm | 9.9 | 76 |
| September | 24.1° | 10.6° | 102.3mm | 8.9 | 82 |
| October | 17.2° | 4.2° | 128.1mm | 10.8 | 69 |
| November | 10.4° | -1.3° | 97mm | 10.1 | 44 |
| December | 4.5° | -5.8° | 117.5mm | 10.4 | 18 |
January in Nashua averages a daily high of 1.6°C with nights around -9.4°C. Expect roughly 9.7 wet days totalling 96.8mm. A hard month to visit for comfort alone.
February in Nashua averages a daily high of 3.3°C with nights around -8.7°C. Expect roughly 8.3 wet days totalling 91.8mm. A hard month to visit for comfort alone.
March in Nashua averages a daily high of 7.6°C with nights around -4.3°C. Expect roughly 8.8 wet days totalling 109.7mm. A hard month to visit for comfort alone.
April in Nashua averages a daily high of 14.7°C with nights around 1.4°C. Expect roughly 11.3 wet days totalling 113.1mm. Generally workable, with some weather to plan around.
May in Nashua averages a daily high of 21.1°C with nights around 7.7°C. Expect roughly 12 wet days totalling 101mm. Comfortable conditions for being outdoors all day.
June in Nashua averages a daily high of 25.7°C with nights around 13°C. Expect roughly 11.2 wet days totalling 106.7mm. Comfortable conditions for being outdoors all day.
July in Nashua averages a daily high of 29°C with nights around 16.4°C. Expect roughly 10.9 wet days totalling 111.8mm. Generally workable, with some weather to plan around.
August in Nashua averages a daily high of 28°C with nights around 15.1°C. Expect roughly 9.9 wet days totalling 99.8mm. Comfortable conditions for being outdoors all day.
September in Nashua averages a daily high of 24.1°C with nights around 10.6°C. Expect roughly 8.9 wet days totalling 102.3mm. Comfortable conditions for being outdoors all day.
October in Nashua averages a daily high of 17.2°C with nights around 4.2°C. Expect roughly 10.8 wet days totalling 128.1mm. Generally workable, with some weather to plan around.
November in Nashua averages a daily high of 10.4°C with nights around -1.3°C. Expect roughly 10.1 wet days totalling 97mm. Demanding conditions — pack for it and plan indoor options.
December in Nashua averages a daily high of 4.5°C with nights around -5.8°C. Expect roughly 10.4 wet days totalling 117.5mm. 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. Nashua peaks at 82.
Based on 30 years of records, May–June scores highest for comfort in Nashua, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29°C.
October is the wettest, averaging 128.1mm of rain across roughly 10.8 wet days.
January is the coolest month, with average daily highs around 1.6°C.