The best time to visit Finland is Jun–Aug. It is the only stretch of the year — 3 months — rated go on both daytime heat and rainfall.
Cold; brief mild summer
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | -1.3 | 30 | 44% | Too cold |
| February | -2.5 | 28 | 39% | Too cold |
| March | 0.3 | 33 | 33% | Too cold |
| April | 5.2 | 41 | 30% | Fair |
| May | 10.6 | 51 | 26% | Fair |
| June | 15.3 | 60 | 34% | Go |
| July | 19.0 | 66 | 33% | Go |
| August | 18.8 | 66 | 42% | Go |
| September | 14.5 | 58 | 40% | Fair |
| October | 8.6 | 47 | 46% | Fair |
| November | 4.1 | 39 | 52% | Too cold |
| December | 0.9 | 34 | 48% | Too cold |
Verdict combines mean daytime high with rainy-day frequency. “Rainy days” is the share of days in the month with at least 1 mm of rain.
May is the driest month, with rain on 26% of days and daytime highs near 10.6°C (51°F). November is the wettest, at 52%. Temperature swings hard across the year — 21.5°C between July (19.0°C / 66°F) and February (-2.5°C / 28°F) — so packing for the wrong month is the main risk. The record rules out too cold in Nov–Mar.