Funafuti, the capital and main atoll of Tuvalu, is a thin ring of coral islets in the central Pacific, barely a few metres above sea level and enclosing a broad lagoon at approximately -8.52°S, 179.20°E. It has a tropical rainforest climate (Köppen Af) — hot, humid and rainy year-round, cooled by ocean breezes — with no true dry season.

There is no summer in the temperate sense: temperatures barely change, with daytime highs around 31°C and warm, humid nights near 25–26°C every month. The wetter, stormier season runs from November to April — the austral summer — with heavy downpours, westerly squalls, and a risk of tropical cyclones, which can be devastating on so low an atoll.

There is no true winter, but the drier, calmer stretch from May to October brings steadier trade winds, slightly less rain and more sunshine, though showers occur in every month. Temperatures remain constant year-round; the difference between the seasons is one of wind and rainfall alone.

Funafuti is wet, receiving on the order of 3,000–3,500 mm of rain a year, with substantial rain in every month and a wet-season peak from November to March; rainwater harvesting is the atoll's principal source of fresh water, as it has no rivers or reliable groundwater. Live rainfall, humidity, and pressure readings for the atoll are shown in the panels above.

Tuvalu is among the nations most threatened by rising seas: Funafuti's coral islets rise barely three or four metres above the ocean, and the highest 'king tides' now regularly push seawater up through the porous coral to flood the interior, while cyclones and storm surge threaten the whole atoll.

To follow any single measurement in Funafuti more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.