| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -0.9° | -6.2° | 54.3mm | 15.4 | 3 |
| February | -0.6° | -6.3° | 40mm | 12.1 | 8 |
| March | 3.1° | -4.2° | 33mm | 11.8 | 13 |
| April | 9.5° | 0.2° | 31.7mm | 9.5 | 45 |
| May | 16.3° | 5.8° | 35.1mm | 9.1 | 70 |
| June | 20.6° | 10.5° | 46mm | 9.8 | 80 |
| July | 23.3° | 13.9° | 64.4mm | 11.3 | 77 |
| August | 21.7° | 13° | 83.2mm | 13.6 | 73 |
| September | 16.5° | 8.8° | 55.3mm | 11 | 67 |
| October | 9.7° | 3.7° | 73.2mm | 14.7 | 38 |
| November | 5° | 0.5° | 70.1mm | 16.1 | 20 |
| December | 1.7° | -3.2° | 72.4mm | 16.7 | 7 |
January in Turku averages a daily high of -0.9°C with nights around -6.2°C. Expect roughly 15.4 wet days totalling 54.3mm. A hard month to visit for comfort alone.
February in Turku averages a daily high of -0.6°C with nights around -6.3°C. Expect roughly 12.1 wet days totalling 40mm. A hard month to visit for comfort alone.
March in Turku averages a daily high of 3.1°C with nights around -4.2°C. Expect roughly 11.8 wet days totalling 33mm. A hard month to visit for comfort alone.
April in Turku averages a daily high of 9.5°C with nights around 0.2°C. Expect roughly 9.5 wet days totalling 31.7mm. Demanding conditions — pack for it and plan indoor options.
May in Turku averages a daily high of 16.3°C with nights around 5.8°C. Expect roughly 9.1 wet days totalling 35.1mm. Generally workable, with some weather to plan around.
June in Turku averages a daily high of 20.6°C with nights around 10.5°C. Expect roughly 9.8 wet days totalling 46mm. Comfortable conditions for being outdoors all day.
July in Turku averages a daily high of 23.3°C with nights around 13.9°C. Expect roughly 11.3 wet days totalling 64.4mm. Comfortable conditions for being outdoors all day.
August in Turku averages a daily high of 21.7°C with nights around 13°C. Expect roughly 13.6 wet days totalling 83.2mm. Generally workable, with some weather to plan around.
September in Turku averages a daily high of 16.5°C with nights around 8.8°C. Expect roughly 11 wet days totalling 55.3mm. Generally workable, with some weather to plan around.
October in Turku averages a daily high of 9.7°C with nights around 3.7°C. Expect roughly 14.7 wet days totalling 73.2mm. Demanding conditions — pack for it and plan indoor options.
November in Turku averages a daily high of 5°C with nights around 0.5°C. Expect roughly 16.1 wet days totalling 70.1mm. A hard month to visit for comfort alone.
December in Turku averages a daily high of 1.7°C with nights around -3.2°C. Expect roughly 16.7 wet days totalling 72.4mm. 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. Turku peaks at 80.
Based on 30 years of records, June–August scores highest for comfort in Turku, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 23.3°C.
August is the wettest, averaging 83.2mm of rain across roughly 13.6 wet days.
January is the coolest month, with average daily highs around -0.9°C.