When is Swarm Season in the Denver Metro?

This swarm was big enough to need two bee vac boxes.

A Swarm in May is Worth a Load of Hay
Definitely true around here. When the evening news starts reporting bears coming out of hibernation, get your gear ready. When you start seeing swallows playing in the ebb-and-flow of metro intersections, it's high swarm season. Spring was late to arrive this year, so I expect swarms to continue well into June.