Climate of Chicago

The climate of Chicago is classified as hot-summer humid continental (Köppen: Dfa, Trewartha: Dca) with hot humid summers and cold, occasionally snowy winters. Although lakefront areas such as Northerly Island have a Cfa (humid subtropical) climate using Köppen's −3 °C (27 °F) winter isotherm, even those areas are continental (Dca) under Trewartha due to winters averaging below 0 °C (32 °F), and inland areas such as Midway and O'Hare International Airports are continental even under Köppen. All four seasons are distinctly represented: Winters are cold and often see snow with below 0 Celsius or 32 Fahrenheit temperatures and windchills, while summers are warm and humid with temperatures being hotter inland, spring and fall bring bouts of both cool and warm weather and fairly sunny skies. Annual precipitation in Chicago is moderate and relatively evenly distributed, the driest months being January and February and the wettest July and August.