We may expect muggy weather when the rainy season begins.

雨季开始时，我们预料有闷热的天气。

《新英汉大辞典》

The season exchange, the weather burning hot, obviously the fall rain muggy weather possibly affects patient's diet and the sleep.

季节交换、天气炎热、显秋阴雨闷热天气可能影响患者的饮食和睡眠。

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Because of the continuous muggy weather this summer, many spring and autumn flowers and trees in Shanghai's urban area are currently blooming one after another, confusing some horticultural experts.

由于今年夏天天气的连续闷热，上海市区内不少属于春秋季的花木目前纷纷开花吐艳，令一些种花行家也大惑不解。

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"Hot and muggy weather and continuous heavy use of air conditioning remain the single largest factor affecting peak electricity demand in the summer, " Edward Schwerdt, president of the power coordinating council, told reporters on a conference call.

WSJ: NE power supply helped by conservation, efficiency