Palau’s climate is hot and humid (average relative humidity is 82%) with mean daily air temperature at around 28°C. There is little season variability in its temperature. The difference between its hottest and its coldest months is 0.8°C approximately. The main wet season is between May and October, with June and August having the largest rainfall. Rainfall can vary between years as a result of El Niño Southern Oscillation (ENSO). El Niño years are drier and La Niña years are on average wetter. Key historical climate trends are summarized below:

Temperature

• Annual mean temperature has increased approximately 0.5°C between 1953-2009.
• Sea surface temperatures influence trends in air temperature. Warming of sea-surface temperature around Palau has grown more rapidly since the 1980s. However, natural variability of sea-surface temperature at a regional level ensures there is difficulty in measuring long-term trends.

Precipitation

• Annual and seasonal rainfall trends measured over the period 1950-2009 are not statistically significant.
• The driest year on record for most of Micronesia happened in 1998, following the major El Niño of 1997.

This section provides the options to visualize historical climate data for different timeframes via map and annual cycle chart.