Climate Change Overview

Country Summary

This page presents high-level information for Tonga's climate zones and its seasonal cycle for mean temperature and precipitation for the latest climatology, 1991-2020. Climate zone classifications are derived from the Köppen-Geiger climate classification system, which divides climates into five main climate groups divided based on seasonal precipitation and temperature patterns. The five main groups are A (tropical), B (dry), C (temperate), D (continental), and E (polar). All climates except for those in the E group are assigned a seasonal precipitation sub-group (second letter).  Climate classifications are identified by hovering your mouse over the legend. A narrative overview of Tonga's country context and climate is provided following the visualizations.


The Kingdom of Tonga is an archipelago consisting of four clusters of 172 coral and volcanic islands with a total area of 747 square kilometers (km2), located in the Central South Pacific Ocean. Tonga is situated at the subduction zone of the Indian-Australian and the Pacific tectonic plates and lies within the Ring of Fire where intense seismic activities occur. The islands are formed on the tops of two parallel submarine ridges stretching from Southwest to Northeast and enclosing a 50 km wide trough. Most of the islands in Tonga originate from coral line, and some islands are of volcanic origin. The majority of these islands are comparatively flat except for those raised by tectonic action. Several volcanoes, some of which are still active, exist along the western ridge, while many coral islands have formed along the eastern ridge, amongst them are the Vava’u and Ha’apai island groups. Coral islands are in two categories, the low and raised coral islands. Tonga’s population is approximately 105,697 (2020) people – about 74% of the total population resides on the largest island of Tongatapu (at 260 km2). Tonga enjoys a relatively strong position as a lower middle-income country. The economy of Tonga is highly dependent on climate sensitive sectors such agriculture, fisheries and tourism and a limited resource base that is sensitive to external shocks. The agricultural sector supports the majority of the population for subsistence and for cash income, employing a third of the labor force and accounting for at least 50% of the export earnings. Over 40% of total land area is also used for agricultural purposes. Tonga is vulnerable to the impacts of climate change from extreme weather events, such as tropical cyclones, increase in sea level, and increase in temperature and precipitation, which increasing the risks of drought, flood, and coral bleaching.