Kiribati has a hot, humid, tropical climate with an average temperature of 28.3°C and average rainfall of about 2,100 mm per year in Tarawa (1980 - 1999). Its climate is closely related to the temperature of the oceans surrounding the small islands and atolls. Across Kiribati the average temperature is relatively constant year-round. From season to season the temperature changes by no more than 1°C. Kiribati has two seasons - the dry season (te Au Maiaki) and the wet season (te Au Meang). The periods of seasons vary from location to location and are strongly influenced by the seasonal movement of the South Pacific Convergence Zone (SPCZ) and the Inter-Tropical Convergence Zone (ITCZ).
The six-month dry season starts in June, with the lowest mean rainfall in October. The wet season starts in November and lasts until April; the highest rainfall occurs from January to March, peaking with a mean of 268 mm in January. The Walker Circulation and associated El Niño and La Niña with their marked opposite conditions of flooding and drought for different parts of the South Pacific and the wider tropical region of the globe are predominating phenomena that determine Kiribati climate. These phenomena have also marked conditions on the temperature and movement (east to west) of the waters of the Central Pacific Ocean, and on wind direction.
- The temperature averages are best described as increasing for the past decades (last 30 to 40 years).
- Maximum temperatures have increased at a rate of 0.18°C per decade. Annual and seasonal minimum temperature have increased slightly more than the increase in maximum temperature.
- Annual and wet season rainfall has increased for Kirimati but there is no trend in the dry season.
This section provides the options to visualize historical climate data for different timeframes via map and annual cycle chart.