Rainforest World Music Festival, July
Gawai Dayak, June
Harvest Festival, May
Chinese New Year, February
Hari Raya Puasa, June
Some of the highest rainfall of the year, particularly in Sarawak, making travel in rural areas difficult. Occasional rough seas and poor underwater visibility.
The weather is hot and humid, with rain always likely. February is one of the wettest months of the year in Kuching (Sarawak) and Banjarmasin (South Kalimantan). The seas off Sarawak and around Kalimantan's Derawan Archipelago can be rough.
Chinese New Year
Borneo's Chinese communities, especially large in Kuching and Sibu in Sarawak and Singkawang in Kalimantan, welcome the New Year with bright red lanterns, lion and dragon dances, drums, night markets and fireworks. Some years the Chinese New Year kicks off in January.
Generally dry weather, particularly in Sabah – good for trekking and visiting the islands. Low visitor numbers, plus whale sharks making an appearance.
Shoulder month between two monsoons, with particularly hot and dry weather in Sabah – good for jungle trekking and island hopping.
Baleh-Kapit Raft Safari
This challenging race, spread over two days, re-creates the experience of the Iban and Orang Ulu people who used to travel downstream by raft to bring their jungle produce to Kapit. Held in late spring, often in April.
The Bajau sea gypsies of Semporna (Sabah) deck out their lepa (boats) with streamers, bunting, flags, ceremonial umbrellas and gorgeously decorated sails. The mid-April weekend festivities are further animated with violin, cymbal and drum music, and tug-of-war contests with boats.
This quiet, mostly dry month before the school holidays is a good time for trekking and diving.
Borneo Jazz Festival
An eclectic assemblage of artists from Europe, North America and Southeast Asia makes the Borneo Jazz Festival (www.jazzborneo.com) – held in Miri in Sarawak on a weekend in mid-May – Borneo's premier jazz event.
During the month of Ramadan, Muslims abstain from eating and drinking during daylight hours. Ramadan food markets pop up in cities and celebratory meals to break the fast are held after sundown.
Rice is the key staple for Sabah's indigenous groups. To mark the annual harvest, people gather in their home villages on 30 and 31 May for a colourful thanksgiving festival, also known as Pesta Kaamatan, that involves much rice wine.
June is the wettest month of the year in Balikpapan (West Kalimantan). It's fruiting season, so it's easier to spot orangutans in the jungle. As it's the northern hemisphere summer, tourist numbers rise.
Official holiday (31 May to 2 June) in Sarawak (also celebrated in West Kalimantan and by Brunei's Iban), Gawai marks the end of the rice harvest. Folks return to their longhouses to make music, eat and drink tuak (rice wine).
Hari Raya Puasa
This festive three-day Muslim holiday marks the end of the fasting month of Ramadan. Many people travel to their hometowns, with transport booked up well in advance. The Sultan of Brunei opens his palace to visitors.
The driest month in Kuching, but expect rain nonetheless. Northern hemisphere tourist numbers are high so consider booking guides for treks and tours in advance.
Bario Pesta Nuneken Festival
Visitors flock to the Kelabit Highlands in Sarawak for July's three-day Bario Pesta Nukenen Festival. Cultural performances incorporate delicacies including wild spinach, asparagus and ginger, and plenty of sweet and juicy Bario pineapples.
Borneo Cultural Festival
An exuberant week-long festival in Sibu (Sarawak) of food, music and dance representing Central Sarawak’s Chinese, Iban, Bidayuh, Orang Ulu and Malay-Melanau cultures and traditions.
Sultan of Brunei's Birthday
Colourful official ceremonies are held on 15 July to mark the birthday of Sultan Hassanal Bolkiah. In Bandar Seri Begawan, events include an elaborate military ceremony and cannon-firing presided over by the sultan himself.
Rainforest World Music Festival
This three-day musical extravaganza (www.rwmf.net), held in the Sarawak Cultural Village near Kuching in July or August, brings together local bands and international artists. Accommodation fills up long in advance.
Kuching's arty and alternative side is showcased with 10 days of music, art, dance and photography leading up to and during the city's annual Rainforest World Music Festival.
While August is the driest month in Banjarmasin (South Kalimantan), rain is always likely. Northern hemisphere tourist numbers remain high. Good time of year for wildlife spotting.
The Erau Festival sees thousands of Dayaks from all over Kalimantan converging in Tenggarong in a whirl of tribal costumes, ceremony and dance – an international celebration of traditional cultures.
Hungry Ghost Festival
On the 15th day of the seventh Chinese lunar month, when ghosts are free to roam the earth, offerings of food, prayer, incense and (fake) paper money are made to appease the spirits of the deceased.
Kuching Festival Fair
For three weeks in late July and August, scores of evening stalls serve the delicious dishes of Kuching's various Chinese communities, Nonya desserts and beer. Held about 2km southeast of the city centre, next to Kuching South City Hall (MBKS Building).
Haze from forest and field-clearance fires in Indonesia create urban smog across the region, particularly in western Sarawak. Good weather for wildlife spotting in Sabah.
Belaga Rainforest Challenge
Orang Ulu longhouses along the Batang Rejang share their music, dance, traditional costumes and cuisines with each other and visitors. Competitions include boat races and a 20km jungle run. Held in even-numbered years, it lasts for five days.
Borneo International Kite Festival
Held on the runway of the old airport in Bintulu (Sarawak), this festival (www.borneokite.com) brings a marvellous array of kites to Borneo's natural-gas capital. Takes place over four or five days in September or October.
Colourful festivities, musical performances and stalls selling food, drink and, of course, mooncakes take over Jalan Carpenter in Kuching's Chinatown for about a week. The Mid-Autumn Festival is also celebrated in other towns with large Chinese communities.
Borneo Arts Festival
Pulau Labuan's biggest culture fest, with live music and a variety of cultural events over three days in late September.
Rains tend to set in by the end of the month, but it's otherwise a good time to dive in Sipadan and see orangutans in the wild.
The Hindu 'Festival of Lights' is celebrated throughout Borneo, with gifts exchanged and an open-house policy.
What About Kuching
This community-led festival presents a month of cultural, art and musical events all around Kuching. Launched in 2017 it's an excellent opportunity for grassroots organisations and emerging artists and performers to make an impact.
Rain and thunderstorms increase, there are low visitor numbers and it's more difficult to spot wildlife.
Rainy season all over Borneo, though Sabah gets less rainfall. Rough seas and poor diving visibility.
Muslim and Chinese festivals follow a lunar calendar, so the dates for many religious festivals vary each year. Muslim holidays typically move forward 11 days each year, while Chinese festivals change dates, but fall roughly within the same months. Contact local tourist offices for exact festival dates, as many are variable.