Relating to or characteristic of summer.
The word 'summerly' makes people think of warm weather, vacations, and outdoor fun.
Examples:
The summerly weather makes me want to go to the beach.
We had a summerly picnic in the park.
She wore a summerly dress to the party.
The ice cream truck comes around more often in summerly weather.
In summerly places, it's always warm and sunny.
I love the summerly feeling of the sun on my face.