The best time to visit Poland is May–Sep. It is the only stretch of the year — 5 months — rated go on both daytime heat and rainfall.
Cold winters, warm summers
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | -0.8 | 31 | 35% | Too cold |
| February | 1.5 | 35 | 36% | Too cold |
| March | 7.0 | 45 | 31% | Fair |
| April | 14.0 | 57 | 32% | Fair |
| May | 19.4 | 67 | 40% | Go |
| June | 22.8 | 73 | 43% | Go |
| July | 25.3 | 78 | 44% | Go |
| August | 25.3 | 78 | 35% | Go |
| September | 19.9 | 68 | 32% | Go |
| October | 13.1 | 56 | 29% | Fair |
| November | 5.9 | 43 | 34% | Fair |
| December | 0.6 | 33 | 33% | 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.
October is the driest month, with rain on 29% of days and daytime highs near 13.1°C (56°F). July is the wettest, at 44%. Temperature swings hard across the year — 26.1°C between July (25.3°C / 78°F) and January (-0.8°C / 31°F) — so packing for the wrong month is the main risk. The record rules out too cold in Dec–Feb.