天气晴朗用英语可以说成 "The weather is clear." 来源于拉丁语 "clarus"，意为清晰、明亮。

例句：

It's a beautiful day. The weather is clear and the sun is shining.

今天真漂亮。天气晴朗，阳光灿烂。

We're going on a picnic. The weather is clear and it's the perfect day for it.

我们要去野餐。天气晴朗，正是野餐的好日子。

The weather is clear and it's a great day for a hike.

天气晴朗，这正是徒步旅行的好天气。