Compared to a little while ago, the temperature is getting warmer during the same time of the day.
ご質問ありがとうございます。
"Compared to a little while ago,"=「少し前と比べると」
"the temperature is getting warmer"=「気温は暖かくなってきている」
(☆"temperature"の代わりに"weather"(天気)と言ってもOKです)
"during the same time of the day."=「一日の同じ時間帯に。」
ご参考に。