User blog comment:Ygrain/Long Days, Long Nights 5/@comment-5287758-20121013134952/@comment-5267262-20121013163706

How cold nights and hot days get can be generally related to cloud cover. Where there is lots of cloud, days are colder, nights are warmer. In deserts, where there is almost no cloud, Days are warm and nights are cold (because clouds insulate). Clouds are more frequent where there are lots of plants.