How cold is to cold for bees before they stop coming out of their hive to collect pollen and nectar ?
It depends on wind, sun, and temp. 60 Sunny no wind they will fly good. 60, cloudy, and windy they fly but not worth a crap. If they got something close I know a few dare devils will fly in the 40's if there hive is in the sun and out of the wind. A rule of thumb I guess would be about 60, after that they don't do much. These are in reference to my Italians.
Thats about all I can tell ya.
I've seen my russians fly with snow on the ground and suck up maple sap in the late winter, around 35 degrees but sunny and still.
I too have seen my mutts flying in the 30 degree range. I will guarantee you though that if they stop for a snack they don't come back! :-D I usually see sustained flight activity at about th 45f to 50f.
I've seen them fly around 35-40 degrees but usually if it's closer to the 35 range, they go about 10 feet and land in the snow.
It's not unusual for them to not fly when it's 50 F or below. It's not unusual for them to not fly when the wind is 20 mph. But then I've seen them fly at 27 F with dead calm and sun shine. I've seen them fly in 40 mph when it was warm and sunny and they were finding complex paths to block the wind for their trip for water.