Porto lies just to the north of a coastal Mediterranean climate zone that encompasses most of central and southern Portugal. Summers are typically sunny with average temperatures between 15°C and 25°C but can rise to as high as 40°C during occasional heat waves. Winter temperatures typically range between 5°C during morning and 14°C during afternoon, but can rarely drop below 0°C at night.[12] The weather is often rainy for long stretches, although prolonged sunny periods do occur.