Many migraine sufferers appear to be especially sensitive to weather-related triggers, such as very hot and cold temperatures. "Weather changes may cause imbalances in brain chemicals, including serotonin, which can prompt a migraine," says Jerry W. Swanson, MD, a neurologist at Mayo Clinic in Rochester, MN. One evolutionary explanation: Head pain could prompt someone to seek shelter as adverse weather approaches. Dr. Swanson recommends staying indoors when it’s particularly cold or windy to keep migraines at bay.