The best time to visit Bali, Java & Sumatra is Jun–Sep. Month by month, the verdicts rate May–Oct as comfortable on both daytime heat and rainfall — 6 months in all.
Dry May–Sep, wet Nov–Mar
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 28.0 | 82 | 88% | Too wet |
| February | 27.7 | 82 | 90% | Too wet |
| March | 28.1 | 83 | 77% | Too wet |
| April | 28.2 | 83 | 66% | Too wet |
| May | 27.8 | 82 | 42% | Go |
| June | 27.0 | 81 | 29% | Go |
| July | 26.5 | 80 | 22% | Go |
| August | 27.0 | 81 | 15% | Go |
| September | 28.3 | 83 | 16% | Go |
| October | 29.6 | 85 | 33% | Go |
| November | 29.7 | 85 | 62% | Too wet |
| December | 28.7 | 84 | 83% | 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 15% of days and daytime highs near 27.0°C (81°F). February is the wettest, at 90%. Temperature barely moves all year — just 3.2°C between the warmest and coolest months — so rainfall, not heat, decides when to go. The record rules out too wet in Nov–Apr.