Trends and Extremes of Near-Surface Dry-Bulb, Wet-Bulb, and Dewpoint Temperature across Southeast Asia and Northern Australia (1980–2021)

Abstract Trends in seasonal average dry-bulb temperature T , wet-bulb temperature T WB , and dewpoint temperature T D over the last 42 years (1980–2021) were analyzed over the Southeast (SE) Asian and tropical northern Australian region. All three variables show broad positive trends in most areas, except for relatively weak, nonsignificant trends over northern Australia. Trends in T D and T WB are as high as 0.5°C decade −1 in parts of SE Asia, with generally slightly smaller observed trends in T WB than in T . Trends over the ocean tend to be less variable and slightly weaker on average. We observe an increased occurrence of extreme events in recent years (the 2010s) compared to earlier decades. The T , T WB , and T D extremes occur substantially more frequently during El Niño years, in addition to an underlying increasing trend. Significance Statement Heat stress, a combination of high temperature and humidity, is a major issue in the tropics, where population density is high. Increasing temperature and humidity trends and the occurrence of extreme dry- and wet-bulb temperatures across Southeast (SE) Asia over recent decades are of particular concern for human and ecosystem health.