Season by season
Dry season (May–October)
Dry season (roughly May–October) is the main trekking season: clearer skies, firmer trails and the best summit views, though nights at the rim are coldest in July and August. It is also the busiest — book treks ahead for July and August.
Wet season (November–April)
Wet season (roughly November–April) brings afternoon storms, cloud and slippery trails. The park normally closes the trails from about January to March. The waterfalls are spectacular, but the Tiu Kelep crossing can be impassable after heavy rain.
Sea, surf & trail conditions
On the mountain the weather changes quickly in any month. Morning is usually clearest; cloud often builds around the rim by midday. Dust on the summit scree is worst late in the dry season.
Month by month
| Month | Avg high | Avg low | Rainfall | Crowds |
|---|---|---|---|---|
| January | 26°C | 18°C | 380 mm | Quiet |
| February | 26°C | 18°C | 340 mm | Quiet |
| March | 26°C | 18°C | 300 mm | Quiet |
| April | 27°C | 18°C | 180 mm | Busy |
| May | 27°C | 17°C | 110 mm | Busy |
| June | 26°C | 16°C | 60 mm | Busy |
| July | 26°C | 15°C | 40 mm | Very busy |
| August | 26°C | 15°C | 25 mm | Very busy |
| September | 27°C | 16°C | 55 mm | Busy |
| October | 27°C | 17°C | 160 mm | Busy |
| November | 27°C | 18°C | 280 mm | Quiet |
| December | 26°C | 18°C | 360 mm | Quiet |
Temperatures and rainfall are approximate long-term averages for the area, rounded; individual years vary, and mountain villages are cooler and wetter than the coast.
Festivals & events
- Rinjani trail opening — the park announces the reopening of the trails after the wet-season closure, usually around April; dates vary by year.
- Pilgrimages to Segara Anak — Hindu and Wetu Telu pilgrims visit the lake and hot springs at certain times of the year; treat ceremonies with respect.
- Ramadan and Eid — dates move each year. Services continue, but expect quieter villages and busy roads around Eid.
Our advice
For a trek, aim for May, June, September or October: dry enough for good views, with fewer groups than in July and August. For the waterfalls, any month works — but go in the morning, before the afternoon rain and the tour buses.
