The mornings around here have been pleasantly cool while the afternoons have been quite warm, leading to much (much!) time spent outside. Painting with liquid sidewalk chalk (recipe here).
Selecting branches to make bats to "play baseball."
Bubble snakes (instructions here).
A renewed interest in the balance bike. He likes to go off-road and ride it on the grass and "go downhill!"
Lately he's been very interested in shadows. This one caused him to exclaim, "mama, the garbage truck's shadow looks like a boat!"