I've been tired since this morning.
I’m still tired from yesterday.
But the weather is great today.
It’s hard to believe it rained yesterday.
I guess I should go out.
朝から体がだるい。
昨日の疲れが残っている。
だけど外はいい天気。
昨日の雨が嘘のようだ。
出掛けないとな。
hard to believe：信じる事が難しい
I guess:多分、～かもね