What's the weather like today?

今天天气怎么样?

The weatherman predicts a fine day today.

天气预报员说今天是一个好天气。

How's the weather today?

今天天气怎么样?

What's it like outside today?

今天外面天气怎么样?

What sort of day is it?

今天是什么样的天气?