Tonga's climate can be described as warm, tropical climate. Temperatures are warm all year round and can get hot in the summer, but seldom reaches above 35°C. Trade winds from the east southeast bring year long cooling breezes late afternoon and early evening.
The tropical rain season is from December through February coinciding with the warmest summer months. Tonga is situated in the southern Hemisphere, so "Summer" lasts from November to February and "Winter" from April to September. However, there are no significant Differences in Temperature; in general, the Temperatures between April and September are only slightly cooler than from November to February.
Typhoons can sometimes hit Tonga from end January to Mid March, and can cause heavy rainstorms, Flash floods and erosion. However, these Storms are mostly not a danger for Tonga, because the usual routes of these Storms are often too far south in the Southern Hemisphere Typhoon Season, and not every Typhoon that hit Tonga is a strong one.
Lightweight cotton clothing is advised throughout the year, with an umbrella or raincoat for sudden cloudbursts. No matter where you go, be prepared for high temperatures and humidity.
The Climate of Tonga can be classified as Af climate, a hot, humid tropical climate with all months above 18°C.