Minimum daytime temperature for inspecting a hive?
I am a new beek, and a friend here in Denver has a couple of hives and has not been able to inspect them all season due to medical issues. He has asked me to open the hives and see how they are doing. It is getting late in the season and we have been getting some cooler weather here in Denver. At this point in the Fall, there is probably not a lot that could be done to a hive if it is having problems, except feed it if it is light on honey stores, but he still wants an idea of the status of the hives.
I am wondering what is the minimum daytime temp which is still warm enough to open a hive and do a relatively thorough inspection such as locate the queen, check for eggs, estimate honey stores, look for any signs of diseases and hive pests, etc., without endangering the hive due to the cool/cold weather? 50F? 55F? 60F? 65F? 70F?
(3rd year, 11 hives, Zone 5b, 5400 ft, 15.8" annual rainfall)