Sea temperature in the Maldives: what to expect in the water

Very warm, and remarkably steady. NOAA Coral Reef Watch, part of the US National Oceanic and Atmospheric Administration, monitors sea surface temperature over the Maldives by satellite every day. Its long-term monthly averages show only about a 1.6°C difference between the coolest month and the warmest.

In practice, you get bath-warm water whether you visit in January or August.

A few points to keep in mind:

• These figures are for the surface of the open sea, measured from space. A shallow lagoon on a still afternoon can feel noticeably warmer.
• Water a few metres down is usually a touch cooler than the surface, and divers sometimes pass through cooler layers, especially near channels.
• Individual years vary. Recent years have often run warmer than the long-term average.

The table below uses NOAA Coral Reef Watch’s long-term monthly mean climatology for its Maldives monitoring station (rounded to one decimal place).

Season names follow the Maldives Meteorological Service: the northeast monsoon is the dry season (January to March), the southwest monsoon is the wet season (mid-May to November), and April and December are transition months.

The warmest months

The sea is at its warmest in April and early May. The Met Service also describes March and April, running up to the start of the southwest monsoon, as the warmest time of year on land. If you visit in April, expect the water to feel almost too warm in shallow lagoons by mid-afternoon.

The “coolest” months

From June onwards the southwest monsoon brings more wind, cloud and rain. Stirred-up water and less sunshine take the edge off the surface heat. Even so, the sea rarely drops much below 28°C on average. December and January are slightly cooler again, but you would struggle to notice the difference in the water.

The Maldives sits in the tropical Indian Ocean, close to the equator. Several things keep its waters warm through the year:

• Strong sun all year. Near the equator the midday sun is high in every month, so the sea gains heat steadily.
• Small seasonal change. There is no real winter. Air temperatures stay warm in every month, which the Met Service puts at an average range of about 25°C to 32°C.
• Open ocean all round. The atolls are surrounded by deep, warm ocean rather than a cold coast or large river mouths.
• Monsoon winds, not seasons of cold. The main change through the year is the switch between the two monsoons, which alters wind, cloud and rain more than temperature. You can read more in our guide to the Maldivian monsoons, hulhangu and iruvai.

Because the sea is so warm, comfort is less about warmth and more about the sun and the odd sting.

Swimming and snorkelling

• Most people need nothing more than swimwear.
• A long-sleeved rash vest or a thin full-length suit is a good idea. It protects your back and shoulders from sunburn while you float face down, and from minor stings and scrapes. See our sun safety guide.
• On a local island, wear modest swimwear away from designated bikini beaches.

Our snorkelling guide covers reefs, currents and safety in more detail.

Diving

Divers spend much longer in the water, often at depth, so even 28°C water can feel cool after a while. As a general guide:

• Many divers are comfortable in a 3 mm shorty or a thin full suit.
• If you feel the cold easily, or are doing several dives a day, a 3 mm full suit is a common choice.

If you dive often, bringing your own well-fitting suit is worth the luggage space. For the basics, see learning to dive in the Maldives.

Warm water is wonderful for swimmers, but the reefs are living right at the edge of what they can tolerate. When the sea stays unusually hot for weeks, corals expel the tiny algae that live in their tissues and give them colour and food. The coral turns white. This is called bleaching. If the heat eases soon enough, corals can recover. If it lasts too long, they can die.

How bleaching is measured

NOAA Coral Reef Watch uses a simple method:

• It takes the average temperature of the warmest month as the baseline. For its Maldives station, that is about 29.7°C (April).
• Corals are considered under stress when the sea is 1°C or more above that baseline, so roughly 30.7°C for the Maldives.
• It then adds up how long and how far the sea stays above that line over 12 weeks. This is measured in “degree heating weeks”.
• At about 4 degree heating weeks, reef-wide bleaching is likely. At about 8, bleaching with the death of heat-sensitive corals is expected.

NOAA publishes alert levels from “Bleaching Watch” up to “Alert Level 5” based on these numbers.

Recent bleaching events

Bleaching was first identified on Maldivian reefs in 1998, and 2016 was the largest event, according to the then Environmental Protection Agency (as reported by Edition). In 2016, a survey found about 60% of coral colonies were bleached.

In 2024 the sea heated up again. NOAA’s Maldives data shows heat stress passing 8 degree heating weeks from mid-May to late June 2024. In response, the Environmental Protection Agency suspended dredging, reclamation and similar reef work from 9 May to 10 June 2024 (as reported by Edition). Its work has since moved to the Ministry of Tourism and Environment.

In April 2026, local reef groups again flagged a NOAA bleaching alert for the Maldives (as reported by Atoll Times). Heat stress that year stayed well below 2024 levels in NOAA’s data.

How you can help

• Never touch, stand on or kick coral. Stressed corals are even more fragile.
• Keep fins up and off the reef; practise buoyancy before you dive over shallow coral.
• Do not feed fish or other marine life.

Our guides to coral reefs of the Maldives and coral restoration explain more. Healthy reefs also protect low-lying islands from waves, a link covered in Is the Maldives sinking?.

Dhiffushi sits on the eastern rim of North Malé (Kaafu) Atoll, with the open ocean on one side and the atoll lagoon on the other. The water is just as warm here as elsewhere in the country. On calm days, the house reef and shore snorkelling spots are easy to enjoy in nothing more than swimwear and a rash vest. For boat trips and dives from the island, see diving and snorkelling in Dhiffushi.