It's mild for the time of year.

Meaning

The weather is warmer than usual for this season.

Examples

• John: It's a lovely day, isn't it?
• Alice: Yes, <b>it's mild for the time of year</b>. I'm surprised.
• John: I was expecting colder temperatures.
• Alice: Me too. I'm enjoying this unexpected warmth; <b>it's mild for the time of year</b>.