YOU SAID:
The weather is nice today
INTO JAPANESE
天気が今日はいいです
BACK INTO ENGLISH
The weather was better today.
INTO JAPANESE
天候も今日よかった。
BACK INTO ENGLISH
The weather is good today.
INTO JAPANESE
今日は天気が良いです。
BACK INTO ENGLISH
Today the weather is good.
INTO JAPANESE
いい天気ですね。
BACK INTO ENGLISH
It's nice weather.
INTO JAPANESE
天気の良い日です。
BACK INTO ENGLISH
Weather is a good day.
INTO JAPANESE
天気が良い日です。
BACK INTO ENGLISH
It is a sunny day.
INTO JAPANESE
晴れた日です。
BACK INTO ENGLISH
It is a sunny day.
That didn't even make that much sense in English.