Things everybody “knows” about climate zones

MythWeather and climate are the same thing.

FactThe big difference between weather and climate is time: weather is hours or days, climate is years or decades. Met Office: What is climate? The Met Office’s way of putting it: climate decides which clothes are in your wardrobe; weather decides what you wear today. Met Office: What is climate?

MythClimate is just the average weather.

FactBritannica says climate is not just the “average weather”: it includes the extremes, the variability and how often things happen. Encyclopaedia Britannica: climate

MythAll deserts are hot.

FactNot all deserts are hot. In the Gobi Desert of east Asia, the yearly average temperature can be below 0 °C. Met Office: Climate zones With no clouds to hold the heat in, deserts swing hugely between day and night: some of the hottest places on Earth drop below freezing at night. Met Office: Climate zones

MythIt never rains in a desert.

FactLow-latitude deserts mostly get 0–25 cm of rain a year, but how unreliable it is matters more than the small totals. Encyclopaedia Britannica: tropical and subtropical desert climate A desert averaging 5 cm of rain over ten years might have had 50 cm in one wet year and almost none in the other nine. Encyclopaedia Britannica: tropical and subtropical desert climate

MythPlaces at the same latitude have the same climate.

FactThe UK is at the same latitude as most of Canada but has a much milder climate, thanks to the Gulf Stream and the North Atlantic. Met Office: Climate zones The western and eastern sides of a continent can have very different climates, because of the direction of the prevailing winds. Met Office: Climate zones

MythKöppen got his system finished in 1884.

FactThe climatologist Wladimir Köppen first developed his climate classification in 1884, and scientists all over the world still use versions of it. Met Office: Climate zones Köppen published his first full scheme in 1900 and a revised version in 1918, and kept revising it until he died in 1940. Encyclopaedia Britannica: Köppen climate classification

MythEvery source puts the temperate–continental line at the same temperature.

FactRule for C: warmest month 10 °C or more, coldest month below 18 °C but above −3 °C. Encyclopaedia Britannica: Köppen climate classification The Met Office describes temperate climates with a 0 °C line instead: coldest month between 0 °C and 18 °C, at least one month above 10 °C. Met Office: Climate zones

MythThe tropics have a hot summer and a cold winter.

FactThere, winter and summer mean little; wet and dry seasons set the rhythm of the year instead. Encyclopaedia Britannica: Köppen climate classification In the tropics the difference between day and night is usually bigger than the difference between the warmest and coolest months. Encyclopaedia Britannica: Köppen climate classification

MythTundra is only found in the far north.

FactThe summits of Ben Nevis and Cairn Gorm in Scotland are in the tundra climate zone. Met Office: Climate zones When tundra climate happens high on mountains, it is usually called an Alpine climate. Met Office: Climate zones

MythMountains were one of Köppen’s original groups.

FactHighland climates were not part of Köppen’s own systems; the H group was added later for mountain areas. Encyclopaedia Britannica: highland climate Köppen didn’t include mountains as their own group, but a highland group, H, is sometimes added for land above 1,500 metres. Encyclopaedia Britannica: Köppen climate classification

MythClimate zones are fixed for ever.

FactAs the climate warms, the map of climate zones will change too. Met Office: Climate zones