Tanzania has two good windows: February and Jun–Oct. They sit either side of the season the climate record rules out, which is why the shoulder months matter here. The recommended window is Jun–Sep.
Two rainy seasons
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 29.9 | 86 | 49% | Fair |
| February | 30.3 | 87 | 44% | Go |
| March | 30.0 | 86 | 70% | Too wet |
| April | 29.2 | 85 | 86% | Too wet |
| May | 28.3 | 83 | 59% | Too wet |
| June | 27.7 | 82 | 20% | Go |
| July | 27.4 | 81 | 13% | Go |
| August | 27.7 | 82 | 12% | Go |
| September | 28.5 | 83 | 15% | Go |
| October | 29.4 | 85 | 31% | Go |
| November | 29.8 | 86 | 59% | Too wet |
| December | 30.0 | 86 | 66% | Too wet |
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.
August is the driest month, with rain on 12% of days and daytime highs near 27.7°C (82°F). April is the wettest, at 86%. Temperature barely moves all year — just 2.9°C between the warmest and coolest months — so rainfall, not heat, decides when to go. The record rules out too wet in Mar–May, Nov–Dec.