Fiji Climate

Fiji's climate is warm and tropical year-round, even in the islands’ “winter” months. The average temperature in Fiji is 25°C (77°F), but it can climb to above 30°C (86°F) in summer (December and January) and sink to 18°C (64°F) in winter (July and August).
Many people consider the Fijian winter, which is the dry season from May to October, to be the best time to visit the islands. This is when it is drier, less humid and a bit cooler, so outside activities are more pleasant. However, this is also Fiji's peak tourist season so the prices for airfare and accommodation peak as well, especially in June and July.
Tradewinds and rainfall in Fiji 
The tradewinds, which blow from the southeast, usually prevail from May to October (the drier winter months). In December and January, the winds often shift and come from the east, bringing rainfall with them. The humid southeastern shorelines of the big islands receive 3,000 mm of rainfall each year, increasing to 5,000 mm inland.
The leeward northwestern coasts are drier and receive about 1,500 to 2,000 mm of rainfall per year. But even in Fiji's wet season (the summer months from November to April), the sun often follows a rain shower and it is warm, so the rain is often only a small inconvenience. During the rainy season, Fiji is more prone to experience hurricanes and tropical storms. Fiji's hurricane season usually lasts from November to April.
Wet and dry zones
Certain areas in the Fijian archipelago receive much more rainfall than others. The islands have distinct wet and dry zones. Roughly speaking, the wet zone is located in the southeast region of each island, while the leeward areas in the north and west are usually drier. An exception to this rule is Suva, which is not always dry in the official dry season (June to October). However, much of the rain falls at night.
Fiji ocean temperature
The ocean surrounding Fiji usually has a pleasant temperature around 27°C (81°F), so ocean activities, such as swimming, snorkeling and diving can be enjoyed year-round. The nearshore waters are usually clearer during the drier season, when scuba divers enjoy increased visibility around the coral reefs.