Are Kuwait’s urban areas cooler by day but hotter by night?

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The global rise of urbanization has led to surface urban heat islands and surface urban cool islands. Urban heat islands have been shown to increase thermal discomfort, which increases heat stress and heat-related diseases. Kuwait has a hyper-arid desert climate, and most of its population lives in urban and suburban areas.

The researchers mapped the spatial distribution of land surface temperatures and investigated urban heat and cool effects in Kuwait. They used historical Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra satellite 8-day composite land surface temperature (LST) data from 2001 to 2017. They calculated average LSTs for urban and suburban governorates and compared them with average LSTs of rural and barren lands. They repeated the analysis for daytime and nighttime LST.

During the day, the reported temperature difference was −1.1 °C (95% CI: −1.2 to −1.00; p < 0.001), indicating a daytime urban cool island. At night, the urban/suburban versus rural governorate difference was 3.6 °C (95% CI: 3.5 to 3.7; p < 0.001), indicating a nighttime urban heat island.

Against the backdrop of rising temperatures in Kuwait, the authors say the work can inform climate change adaptation, including urban planning policies, and may improve temperature exposure assessment for future population health studies.