Recent climate data reveals that 2025 has become the fifth warmest year on record in the western Pacific. This is part of an ongoing warming trend that is significantly altering conditions across the region. According to the ERA5 dataset from the Copernicus Climate Change Service, 2025 ranked as the third warmest year globally, following the exceptionally high temperatures recorded in 2024 and 2023.
In the western Pacific, 2025’s average air temperature was measured at 0.65 °C above the baseline from 1961 to 1990. Since 1940, temperatures in this area have consistently risen by about 0.1 °C per decade. Notably, every year since 1986 has outpaced the long-term average, and the five hottest years recorded have all occurred since 2016.
Particularly warm conditions were reported over the western equatorial Pacific and the Coral Sea, encompassing regions around Papua New Guinea and New Caledonia. This warming is likely associated with record high sea surface temperatures in those areas. Additionally, although the central tropical Pacific saw cooler than average air temperatures due to neutral ENSO or La Niña conditions, both daytime and nighttime temperatures in 2025 were significantly above average—maximally by 0.68 °C and minimally by 0.63 °C, placing them among the top five highest on record.
The ongoing rise in air temperatures in the Pacific underscores the necessity for diligent monitoring. Regional temperature fluctuations may not always align with global averages, yet even minor temperature increases can have profound effects on public health, food security, ecosystems, and daily life in Pacific communities.
Salesa Nihmei, Director of the Climate Science and Information Programme at SPREP, emphasized that the science surrounding climate change in the Pacific is unequivocal. The Pacific Regional Climate Centre Network, in partnership with programs such as the Climate and Oceans Support Program in the Pacific (COSPPac), is dedicated to transforming regional climate data into actionable insights. This supports Pacific nations in anticipating risks and executing early measures to safeguard lives and livelihoods.
The Climate and Ocean Support Programme in the Pacific, funded by Australia and New Zealand, is now in its third phase and aims to provide practical information that is both accessible and applicable. This program plays a vital role in informing governmental planning and international negotiations.
As the Pacific continues to experience rising temperatures, the need for accurate climate information and ongoing regional collaboration becomes increasingly critical for community resilience and adaptation to climate change.