In short
- Visit between July and September for the driest conditions.
- Dry weather means more reliable bat flights at Deer Cave.
- Heavy rain can delay essential flights into Mulu Airport.
In this article
Gunung Mulu National Park is a 60-million-year-old primary rainforest. Rain is frequent all year. However, planning your trip during the right season makes a major difference for outdoor activities and travel logistics.
When is the best time to visit Mulu Caves and Pinnacles?
The best time to visit is during the drier months from July to September.
These months offer the most reliable weather in Sarawak. While rain is still possible, you will face fewer heavy downpours. Drier weather makes exploring the 528.6 square kilometers of rainforest much easier.
How does weather affect the bat exodus?
Bats usually will not leave the cave if it is raining heavily.
Over 3 million wrinkle-lipped bats emerge from Deer Cave at sunset almost every evening. If the weather is wet, they stay inside. Visiting between July and September gives you the best chance of clear skies at dusk. Wait at the observatory after your cave tour to watch them.
Do flights get canceled due to rain?
Yes, heavy rain can delay or cancel flights to Mulu Airport (MZV).
The park is entirely inaccessible by road. Most visitors fly via MASwings from Miri, Kuching, or Kota Kinabalu. Clear weather reduces the risk of flight disruptions and keeps your itinerary on track.
When is the safest time to hike the Mulu Pinnacles?
The Pinnacles Summit Trek is safest during the dry season.
This grueling 2.4 km climb ascends 1,200 meters. You must navigate steep terrain and 15 near-vertical aluminum ladders near the top. Wet conditions make the limestone and ladders extremely slippery. Always wear sturdy, non-slip hiking boots with good grip.
Is Mulu National Park open all year?
Yes, the park and its show caves remain open year-round.
You can still explore massive passages like Deer Cave and Clearwater Cave in wetter months. Entry requires a mandatory 5-day pass. This costs RM 30 for foreign adults and RM 15 for Malaysians. Cave tours cost an additional RM 35 to RM 70.
What should I pack for the rainforest climate?
Always pack a lightweight raincoat or poncho, regardless of the season.
Sudden showers happen even in July. Bring leech socks for jungle treks like the trail to Camp 5. You should also pack lightweight dry bags. These will protect your electronics from rain and splashes on the riverboats.
Questions travellers ask
Are trails closed when it rains?
Trails remain open, but completing them is at your own risk. Once you leave the Park Office, there are no refunds if you cannot complete a trek due to weather or water levels.
Do I need a guide for the caves?
Yes. All treks, cave tours, and adventure activities must be accompanied by an official park guide.
Are mosquitoes bad during the wet season?
Mosquitoes and sandflies are common in the park all year. You should always bring insect repellent.
