Vanuatu’s climate varies with latitude, from wet tropical in the northern islands, which receive over 4,000 millimeters (mm) of annual rainfall to the dryer subtropical in the southern extremes of the archipelago, where annual average rainfall measures 1,500 mm. Average temperatures range from 21°C to 27°C, and unlike many of the Pacific island nations, seasonal temperatures in the capital city of Port Vila exhibit high variability with summertime highs exceeding 30°C and minimum temperatures often reaching below 20°C. Seasonal and interannual variations in climate are driven by changes associated with El Niño, which affect every aspect of the climate in the Pacific. Cyclones are common during the warm months of November to April, although two recent cyclonic events were experienced outside of the traditional cyclonic season.
- Temperatures have been rising in the region at around 0.1°C per decade since the 1970s.
- Up to the 1990s there was limited warming in the region, but from 1995 that warming accelerated, and temperatures between 2014 and 2018 were averaging around 0.5°C - 0.6°C above the long-term average.
- A study has pointed to significant natural multi-decadal rainfall variability in the South Pacific Convergence Zone (which Vanuatu is situated within). Observing records over 400 years, it shows abrupt changes of ~1,800 millimeters (mm) can occur between wet seasons.
- However, no changes in rainfall patterns significantly outside the range of normal inter-annual variation have been documented and linked to human-induced climate changes.