At what temperature may some bees fly outside the hive if the weather is sunny and there is no wind?

Bees are able to fly outside the hive at temperatures as low as 45 degrees Fahrenheit, particularly when the conditions are sunny and windless. This is because warmer temperatures help to loosen the muscles in the bee's thorax, allowing them to generate the necessary buzz to lift off. When the weather is sunny, the sun can also help raise the ambient temperature enough to make it comfortable for bees to venture out for short flights, such as foraging or taking cleansing flights.

Flight activity tends to be minimal below 45 degrees, as bees are more likely to conserve energy and maintain their bodily warmth within the hive. Additionally, the hive environment is often kept at a temperature that promotes bee activity, but if it drops too low outside, their instinct is to remain within the hive's protective warmth. Hence, flight at 45 degrees signals a critical threshold for their outdoor activity when conditions are favorable.