"Sunny or clear" is the meaning.
Probably sunny is the better way to think of it.
So you could say:
今日は晴れですね。
(きょうははれですね。)
Today is sunny, (isn't it?)
Or you could say:
今日は晴れではない。雨が最悪!
(きょうははれではない。あめがさいあく!)
The weather is not nice today. The rain (really) sucks!