I most all states, it is still too cold. Keep in mind the rule: start with 95 degrees, and decrease the temp by 5 degrees a week. So, your 4 week old chicks should be at 75 degrees. It it's sunny, you can turn your light off during the day. At night though, the goal here is not to see what you can get away with, but to insure their survival. My chicks are at 9 weeks old now. We have had day time temps in the 40's-50's, and often with overcast skies, so the light has stayed on (it's out in the hen house), so they can come inside to it and warm up, which they do often. I can do away with the light at night in 2-3 more weeks. BTW, last night it got down to 24 degrees! Don't take the heat away too soon!