Bhutan has two good windows: Feb–Apr and Oct–Dec. They sit either side of the season the climate record rules out, which is why the shoulder months matter here. The recommended window is Feb, Nov–Dec.
SW monsoon Jun–Sep
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 14.8 | 59 | 5% | Fair |
| February | 16.6 | 62 | 9% | Go |
| March | 19.3 | 67 | 23% | Go |
| April | 22.4 | 72 | 41% | Go |
| May | 24.8 | 77 | 55% | Fair |
| June | 26.7 | 80 | 77% | Too wet |
| July | 27.0 | 81 | 92% | Too wet |
| August | 27.3 | 81 | 91% | Too wet |
| September | 26.0 | 79 | 69% | Too wet |
| October | 23.7 | 75 | 22% | Go |
| November | 19.7 | 67 | 2% | Go |
| December | 16.6 | 62 | 2% | Go |
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.
November is the driest month, with rain on 2% of days and daytime highs near 19.7°C (67°F). July is the wettest, at 92%. The warmest month is August at 27.3°C (81°F); the coolest is January at 14.8°C (59°F). The record rules out too wet in Jun–Sep.