summerlike

Low temperatures are much more summerlike, bottoming out by dawn in the mid-60s to around 70 degrees.
D.C.-area forecast: Breezy today but rain-free and sunny for days to come|A. Camden Walker|September 10, 2021|Washington Post
Another challenging fire season underway earlyAn active fire season is already underway in California, as drought and warm conditions have led to summerlike flammability in May.
California facing drought crisis as water shortages mount and fire danger escalates|Diana Leonard, Laris Karklis|May 21, 2021|Washington Post
She had changed her dress for one as summerlike as the other, but still finer and more elaborate.
The Sword of Damocles|Anna Katharine Green
Yet here I was sitting out in a warm, summerlike day in my shirt sleeves, waiting comfortably—and the ducks were coming in, too!
The Killer|Stewart Edward White

The day had been clear and warm, one of the first summerlike days of spring.
Mammals of the San Gabriel Mountains of California|Terry A. Vaughan
The evening was calm, and for the season mild and summerlike.
Tom Burke Of "Ours", Volume II (of II)|Charles James Lever
He laughed and added, "It is pretty summerlike," as if he had not thought of it before.
The March Family Trilogy, Complete|William Dean Howells

Origin of summerlike