Because it is cold-blooded, the body temperature of a butterfly depends on the temperature of its surroundings. To be able to fly, the butterfly must have a body temperature of at least 20 °C, although 30-35 °C is preferable. Most butterflies only fly if the temperature of the surroundings is higher than 17 °C, and they boost their body temperature by basking in the sun. Sheltered places in scrub or at woodland edges as well as bare, sandy patches are therefore important. On cold days, butterflies can warm up in the sun. On the other hand, shadow is just as important on hot summer days, because it provides places where the butterflies can cool down when their body temperature is becoming too high.

Humidity
Most species cannot tolerate dryness and have strict requirements regarding humidity. For a woodland butterfly like the White Admiral, for example, it is important that there are warm, open places available for warming itself up, but also cool, shady places to help prevent it overheating and drying out. The microclimate is also important for the development of the egg, caterpillar, and chrysalis. Some butterfly species deposit their eggs in warm, sunny places, so that development can take place as quickly as possible.

Other species choose a slightly shaded place in order to avoid overheating and desiccation of the eggs. Such choices depend on the species, and the heat-tolerance of different stages.