The best time to visit Bulgaria is Jul–Oct. It is the only stretch of the year — 4 months — rated go on both daytime heat and rainfall.
Cold winters, warm summers
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 2.8 | 37 | 31% | Too cold |
| February | 4.8 | 41 | 35% | Too cold |
| March | 9.1 | 48 | 37% | Fair |
| April | 14.2 | 58 | 41% | Fair |
| May | 19.5 | 67 | 51% | Fair |
| June | 24.1 | 75 | 48% | Fair |
| July | 27.5 | 82 | 37% | Go |
| August | 28.0 | 82 | 28% | Go |
| September | 22.9 | 73 | 29% | Go |
| October | 17.0 | 63 | 25% | Go |
| November | 10.4 | 51 | 28% | Fair |
| December | 4.2 | 40 | 35% | 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 25% of days and daytime highs near 17.0°C (63°F). May is the wettest, at 51%. Temperature swings hard across the year — 25.2°C between August (28.0°C / 82°F) and January (2.8°C / 37°F) — so packing for the wrong month is the main risk. The record rules out too cold in Dec–Feb.