If colder, they need to warm up. They do this by basking in the sun with their wings outstretched to absorb heat. If the temperature goes below 80 F, butterflies can be seen basking before they begin flying. Roosting Butterflies need a place to roost during the night, and often pick the underside of a leaf. If you want to see where they roost, wait until late afternoon and follow them to their roosting spot.
Butterflies also roost during rainy, cloudy, and cold weather.
Usually they spend about 14 hours each day roosting, usually from sunset until midmorning. According to species, butterflies spend the winter in different ways and places. Most, however, winter in the same areas where they spend the summer. The monarch is the only truly migratory butterfly. They migrate as far south as Mexico, returning to West Virginia in the spring.