The Maldives have a tropical climate with warm temperatures year round and a great deal of sunshine. During a 24 year period between 1967 - 1990, the hottest month on average was April, with a maximum monthly mean temperature of 31.5°C and a minimum of 26.5°C. The coolest month was December, with a maximum monthly mean temperature of 29.8°C and a minimum of 25.3°C.
There is a considerable variation of climate between Northern and Southern atolls in the Maldives. In the south the rainfall is greater but so are the number of rain days. Showers are not as heavy as in the North. There are extremes of temperatures in the North also, as the seasons are more evident further away from the Equator.

Monsoons
December - April
NE Monsoon

April
Transition Period

May - November
SW Monsoon

November
Transition Period

The weather is determined to a large extent by the monsoon circulation. Each year there are two monsoons seasons, the north-east monsoon, iruvai and the south west monsoon, hulhangu. The prevailing winds which can become quite strong, are from the SW-W-WN during the south-west monsoon and N-NE-E during the north-east monsoon.
The north-east monsoon brings the driest period, the air having a comparatively short sea track compared with that during the reminder of the year. The relative humidity is only 5% lower than during the south-west monsoon. The hot season is in March and April. In April, calm, windless days are more likely to be experienced than any other time of the year. The transitional period between monsoons begins in April and by the end of May the winds are predominantly W-SW. A fortnight of strong winds and rain usually ushers in the change of seasons.
The wet season is from June to September when the south-west monsoon is firmly set. Gales and moderate to rough seas are common during this season. Cloudy days are more frequent. November is again a transitional period. During October day of light winds are experienced more frequently and by the end of November, winds have shifted from W-NE to N-NE. The effects of cyclones from the Arabian sea can be experienced during this period. The first month of the north-east monsoon, December, is typically rough with strong winds and rain.

Because the Maldives is in the equatorial belt, severe tropical storms and cyclones are extremely rare events. But whenever cyclones form in the Bay of Bengal or Arabian Sea, the spiraling feeder band clouds appear over the Maldives and cause spells of rain and showers. The weather in the north may deteriorate considerably as a result, but there is little effect on the southern islands as it is almost impossible for low pressure areas to develop within 5° of the Equator.

Water Temperatures
Ocean water temperatures rarely vary beyond 27 - 30° C although thermo clines can sometimes be experienced at depths below 20 meters. During the hot periods, water temperatures inside the lagoons increases measurably, influencing water temperatures inside the atolls. During these periods divers are comfortable diving without a wetsuit, although those of slight build may shiver a little. During overcast periods with and rain squalls, it is wise to carry extra clothing on the boat after a dive. Lycra and 3mm wetsuits are popular in tropical waters but some divers prefer a 5mm suit if doing more than one dive a day.