Wonderful
Splendid, Magnificent, The Best
い adjective
An element of clear up (like the sky clearing up!) is so wonderful and splendid. Sort of a weird word, but very useful. Just think of that wonderful feeling you get when the sun breaks and things clear up and it's awesome.
The reading is a bit weird, too. Luckily, you've learned both of them already. 晴れる is はれる. That's the reading you use here, though は goes to ば.
昨日のコンサート、素晴らしかったです！
Yesterday's concert was wonderful!
あの映画のオープニングとカメラワークは実に素晴らしかった。
The opening of that film and the camera work were truly magnificent.
山頂には素晴らしい景色が広がっていた。
A magnificent view extended out from the mountaintop.
「そんな風に自分を安売りしないで。君は素晴らしい女性だよ。」
"Don’t sell yourself short like that. You’re a magnificent woman."