Tonga Weather in May

Locals will say that the Tongan “winter” has begun, but to visitors, it will feel far from your typical winter with temperatures reaching highs of 30°C (86°F). This is particularly to the case with warmer temperatures in the northern islands of Tonga, like Vava’u.

Temperatures are slightly cooler the further south you go, ending with the coolest in Tongatapu and ‘Eua. The lowest temperatures experienced in May are around 22°C (69°F), often at night.

Temperatures Across Tonga

• Tongatapu & Nuku’alofa – The average maximum temperature is 27°C (80°F) and the minimum average temperature is 20°C (68°F)
• Vava’u – The average maximum temperature is 28°C (82°F) and the minimum average temperature is 22°C (72°F)
• Ha’apai – The average maximum temperature is 27°C (81°F) and the minimum average temperature is 22°C (72°F)
• ‘Eua – The average maximum temperature is 27°C (80°F) and the minimum average temperature is 20°C (68°F)
• The Niuas – The average maximum temperature is 30°C (86°F) and the minimum average temperature is 24°C (75°F).

Sea Temperature in May

Tonga has warm sea temperatures all year round, but start to drop a little after the summer season ends and the dry season begins in May. Sea temperatures in May are at an average of 27°C (80°F).

Typical of a winter season, the days start to get shorter in Tonga in May. Nevertheless, “short days” in Tonga might not be considered that short with the average daylight hours still being around 11 hours a day. Sunshine hours are typically around 5 hours a day.

UV Levels During May

While UV levels drop significantly compared to Tonga’s summer months, the UV levels are still around 7+ UV index around midday. Be sure to wear high-factor sunscreen.

For advice on sunscreen and other protection, take a look at The Best Sunscreens for Tonga + Sun Protection Tips.

Sunrise and Sunset During May

May has daylight hours lasting around 11 hours a day in Tonga.

• Sunrise – 6:58 am at the beginning of May and 7:10 am at the end of May
• Sunset – 6:17 pm at the beginning of May and 6:07 pm at the end of May.

Learn more about the local time zone in What is the Tonga Time Zone?

While it’s officially the “dry season” that doesn’t mean that the rain has gone for the whole season. Yes, May does still experience some rainy days, typically 15 days out of the month on average. Showers are usually short-lived, however, not causing too much delay to your travel plans or sunbathing sessions.

Tonga receives an average of 111 mm (4.4 in) of rainfall in the month of May, with around 15 days out of May experiencing rain.

Average Rainfall Across Tonga

• Tongatapu & Nuku’alofa – The average rainfall in May is 111 mm (4.4 in)
• Vava’u – The average rainfall in May is 105 mm (4.1 in)
• Ha’apai – The average rainfall in May is 105 mm (4.1 in)
• ‘Eua – The average rainfall in May is 111 mm (4.4 in)
• The Niuas – The average rainfall in May is 165 mm (6.5 in).

The South Pacific cyclone season starts in November and ends in April, so it’s highly unlikely that a tropical cyclone will occur in Tonga in May. Nevertheless, it’s always best to be prepared, as small-scale cyclones have historically developed across the South Pacific in May.

Check out our tips on How to Prepare for a Cyclone in Tonga for more information on cyclones in Tonga.

For travellers who find cyclones a major concern, perhaps choose a month with less risk, such as July or August.

May is a good time to visit most island groups in Tonga. But if you’re being picky, there is slightly more rainfall and more humidity in Vava’u and The Niues during May. That leaves Tongatapu, Ha’apai and ‘Eua!

Tongatapu – Exploring Tonga's main island is a joy no matter the season, especially considering it's a good idea to have some layover days here in case flights/ferries are rescheduled. Visit Tongatapu’s most popular caves, blowholes, beaches and historical sites with virtually no other tourists around.

Find out more about what to do in Tongatapu in The Complete Guide to Tongatapu.

Ha’apai – Home to some of Tonga’s most idyllic island resorts, Ha’apai is well worth retreating to before the tourist crowds arrive. Learn to scuba dive, snorkel in clear waters, kayak and more! Guesthouses and homestays are also available for an authentic cultural experience.

Learn more about Ha’apai in The Complete Guide to Ha’apai.

‘Eua – One of the closest outer islands to Tongatapu, ‘Eua lures adventurous travellers wishing to see some of the best natural landscapes of the islands. Be sure to land a spot in one of the limited guesthouses or eco-fales before the busy tourist season comes up and everywhere gets fully booked!

Learn more in The Complete Guide to ‘Eua.

May is when you can take a look at the dry season packing list for Tonga! Here are a few essentials and recommendations…

• Light bamboo, linen or merino layers (we like the sustainable bamboo clothing of Moso Morrow)
• Light long-sleeved tops (to cover from the sun and take the edge off those slightly cooler nights)
• Light pants/trousers (something to cover up when out in Tongan towns/villages or going to church)
• Long skirt or sarong (same reason as above, but for women)
• Sunhat
• Sunglasses
• Swimwear
• Rash vest (we like the UV-protecting Sharkskin rashies)
• Flip-flops/sandals
• Closed walking shoes
• High-factor sunscreen (that’s reef-safe and water-resistant)
• Insect repellent.

Get more packing ideas with The Complete Packing List for Tonga.