April in Southeast Asia is usually a hot month, following the cool, dry season and preceding the monsoon season. But April 2016 was not your typical April. Throughout the month, ground-based measurements of air temperatures soared above average; one location in Thailand even broke the national record.
Satellite observations show a similarly hot picture. The map above shows land surface temperatures from April 2016 compared to the 2000–2012 average for the same month. Red areas were hotter than the long-term average by as much as 12 degrees Celsius (22 degrees Fahrenheit) in some places; blue areas were below average. White pixels had normal temperatures, and gray pixels did not have enough data, most likely due to excessive cloud cover.
This temperature anomaly map is based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Observed by satellites uniformly around the world, land surface temperatures (LSTs) are not the same as air temperatures. Instead, they reflect the heating of the land surface by sunlight, and they can sometimes be significantly hotter or cooler than air temperatures.