Spring can be challenging with the wild temperature swings. Lots of folks who brood in sheds or barns have multiple bulbs of different wattages so they don't use more electricity than is necessary or overheat the space. I found with the clear roof on my mini coop that the sun made a big...
Someone will undoubtedly quote the 95 degree number, decreasing five degrees weekly. But, some of us don't even use a thermometer. I just watch the chicks and if they are behaving appropriately, it's fine.