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Why Do Deserts Get Extremely Cold at Night Despite Scorching Days?
为什么沙漠白天酷热，夜晚却极度寒冷？
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Deserts cool rapidly at night because dry air holds very little water vapor to trap heat.
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During daytime, sand absorbs solar energy efficiently but cannot store it for long.
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At sunset, the ground radiates heat back into space with almost no atmospheric 'blanket' to slow loss.
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Clear skies—common in deserts—allow infrared radiation to escape freely and unimpeded.
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Humid regions retain warmth longer because water vapor absorbs and re-emits outgoing heat.
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Temperature swings of 30°C within 12 hours are normal in places like the Sahara or Gobi.
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Plants and animals adapt with burrowing, nocturnal activity, or reflective surfaces to manage extremes.
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Satellite data shows desert surfaces lose heat three times faster than forests or oceans do.
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This rapid cooling also explains why frost sometimes forms in deserts despite annual averages above freezing.
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It’s not the lack of sun—but the lack of moisture—that makes desert nights so chilling.