Flags and bunting hung limply in the still, warm air.

旗子和飘带在静止、温暖的空中无力地垂着。

《柯林斯英汉双解大词典》

With the arrival of warm and pleasant weather, flowers are blooming in the warm air.

随着温暖宜人天气的到来，鲜花在温暖的空气中盛开。

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Birds use warm air currents to help their flight.

鸟利用暖气流助飞。

《牛津词典》

The warm, moisture-laden air brings heavy rainfall and flash flooding to Peru's northern coast, killing villagers and causing havoc to the fragile soils of the desert and of the arid Andean foothills.

ECONOMIST: The unkind child

So any mechanism that acts to suppress that, i.e. warm cloudy days - or hot air - will also kill them.

BBC: Ice blades threaten Europa landing

In the open-air cafes on a warm summer's evening, Bulgarians are sipping their own cooling drinks and refreshing cocktails.

BBC: British entrepreneurs invest in Bulgaria