N5 — outside your level filter
Is said whole, with nothing composed onto it and takes no だ/です, so there are no forms to conjugate.
いいお天気ですね
iiotenkidesunenice weather, isn't itN5expression
Example sentences2
いいお天気ですね、お出かけですか。
ii otenki desu ne, odekake desu ka.
Lovely weather, isn't it — are you heading out? neutral
お足元にお気をつけください、いいお天気ですね。
oashimoto ni oki o tsuke kudasai, ii otenki desu ne.
Please mind your step. It really is lovely weather, isn't it. formal