June - Halfway through the year.
My suggestion for the June Challenge is HALF or HALFWAY. Open to your own interpretation.
You can center your subjects or you can look for themes like Half grown, halfway across the street, halfway up a wall or halfway across the sky. Or perhaps half eaten, half asleep, half done, half full, half dressed, half built, half pint, perhaps halfhearted or even half-assed *:) A partner. One shoe. One earring. Middle.
By the way, halfway can mean in-between or partially complete... you don't have to be precise and catch your subject at exactly halfway.
You'll have to use some imagination, but I don't think it will be too challenging once you start looking.