| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 0° | -4.9° | 42.9mm | 12.6 | 9 |
| February | 0.9° | -5° | 33.9mm | 10.9 | 13 |
| March | 4.9° | -2.8° | 27.8mm | 9.4 | 26 |
| April | 11.2° | 1° | 31.5mm | 9 | 52 |
| May | 16.5° | 5.8° | 45.9mm | 11.1 | 67 |
| June | 20.9° | 10.7° | 60.7mm | 11.4 | 77 |
| July | 23.1° | 13.2° | 76mm | 12 | 76 |
| August | 21.8° | 12.4° | 75.8mm | 12.7 | 75 |
| September | 16.8° | 8.6° | 45.8mm | 10.5 | 69 |
| October | 10.4° | 4.3° | 57.8mm | 12.5 | 44 |
| November | 5.2° | 0.6° | 53.6mm | 14.3 | 22 |
| December | 1.3° | -3.5° | 51.9mm | 15 | 7 |
January in Västerås averages a daily high of 0°C with nights around -4.9°C. Expect roughly 12.6 wet days totalling 42.9mm. A hard month to visit for comfort alone.
February in Västerås averages a daily high of 0.9°C with nights around -5°C. Expect roughly 10.9 wet days totalling 33.9mm. A hard month to visit for comfort alone.
March in Västerås averages a daily high of 4.9°C with nights around -2.8°C. Expect roughly 9.4 wet days totalling 27.8mm. A hard month to visit for comfort alone.
April in Västerås averages a daily high of 11.2°C with nights around 1°C. Expect roughly 9 wet days totalling 31.5mm. Demanding conditions — pack for it and plan indoor options.
May in Västerås averages a daily high of 16.5°C with nights around 5.8°C. Expect roughly 11.1 wet days totalling 45.9mm. Generally workable, with some weather to plan around.
June in Västerås averages a daily high of 20.9°C with nights around 10.7°C. Expect roughly 11.4 wet days totalling 60.7mm. Comfortable conditions for being outdoors all day.
July in Västerås averages a daily high of 23.1°C with nights around 13.2°C. Expect roughly 12 wet days totalling 76mm. Comfortable conditions for being outdoors all day.
August in Västerås averages a daily high of 21.8°C with nights around 12.4°C. Expect roughly 12.7 wet days totalling 75.8mm. Comfortable conditions for being outdoors all day.
September in Västerås averages a daily high of 16.8°C with nights around 8.6°C. Expect roughly 10.5 wet days totalling 45.8mm. Generally workable, with some weather to plan around.
October in Västerås averages a daily high of 10.4°C with nights around 4.3°C. Expect roughly 12.5 wet days totalling 57.8mm. Demanding conditions — pack for it and plan indoor options.
November in Västerås averages a daily high of 5.2°C with nights around 0.6°C. Expect roughly 14.3 wet days totalling 53.6mm. A hard month to visit for comfort alone.
December in Västerås averages a daily high of 1.3°C with nights around -3.5°C. Expect roughly 15 wet days totalling 51.9mm. 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. Västerås peaks at 77.
Based on 30 years of records, June–September scores highest for comfort in Västerås, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 23.1°C.
July is the wettest, averaging 76mm of rain across roughly 12 wet days.
January is the coolest month, with average daily highs around 0°C.