Why do places at the same latitude end up with such different climates?

equator30° N30° S60° NLondonLondonHeathrow, United Kingdomlatitude 51.5° N25 m above sea levelAverage temperatureJanuary 42.1 °F (5.6 °C)July 66.2 °F (19 °C)swing +24.1 °F (+13.4 °C)PrecipitationJanuary 2.31 in (58.8 mm)July 1.80 in (45.8 mm)Average temperature at each stop, °F (January blue, July orange)32 °F4266London
stop
1 of 9: London
latitude
51.5° N
height above sea level
25 m
January to July swing
+24.1 °F

Press the stops in order, or press Auto. Each card shows a station's 30-year normals for January and July. Watch latitude, height above sea level and the ocean nearby.

Climate normals 1991 to 2020: WMO Climate Normals (NOAA National Centers for Environmental Information) and U.S. Climate Normals station files (NOAA NCEI). Ideas from NASA Climate Kids, the NOAA National Ocean Service currents tutorial and Ocean Facts, and the UCAR Center for Science Education. Land outline: Natural Earth (public domain). Conversions between °C and °F and between mm and inches are calculated. Our own drawing.