I'm also in central mass (i agree, the year without a summer. This years weather sucks majorly! First the ice storm, then this!) Just north of Worcester. My 4 Buff Orps moved into the coop on Sunday as they turned 4 weeks old. They definitely still have the heat lamp, but it isn't keeping it as warm as I thought they needed, but they seem fine. At 4 weeks they are supposed to be at 75°, but with the coolness of the past few days I haven't gotten the coop much above 65ish. They don't seem to mind, they are still up and about and not huddling under the light. They have so much more room out there but I miss having them so close by, in the house!
I also put a roost in the brooder around 2 weeks.