Which cities are liveable without air conditioning – and for how much longer?
Hot, cold or just right – how does your city measure up?
Last summer I mapped the cities of the world where the residents can live comfortably without heating or air conditioning.
Working with Guardian Cities to scale up the original survey using data from the US National Oceanic and Atmospheric Administration, we broke the world’s cities into four categories.
First, cities where you probably don't need either heating or air conditioning: average summer temperatures are shy of 26.5C (80F) and the hottest hours of an average summer day are less than 28C (82F), while the winter average is no colder than 13C (55F) and the coldest days no less than 7C (45F). Second, cities that are warmer in the summer, meaning you probably want air conditioning but can still get by without heating. Third, the opposite: cold in winter, not too warm in summer. Lastly, cities with hot summers and cold winters, where you probably want both air conditioning and heating.
The good news is that, if you want to go air conditioning-free, you have options on every single continent. The bad news is that this may not be the case forever.
Using data from the Climate Impact Lab, we have modelled how climate change might affect temperatures globally, making more people dependent on air conditioning in cities where it is currently strictly a luxury.
Average temperature between June and August, 1986-2005
Average temperature between December and February, 1986-2005
The two maps show how average summer temperatures are predicted to rapidly increase in both hemispheres over the next 40 years. In the northern hemisphere, hotter temperatures will creep towards the Arctic circle, while much of northern Africa and the Middle East will see average temperatures climb above 35C (95F) between June and August.
In the southern hemisphere the hottest temperatures occur between December and February. In the next 20 years South American countries such as Argentina and Bolivia are forecast to have average summer temperatures above 35C for the first time since records began.
Whether we face the challenge through international efforts, designing for cooler cities, or by moving to those cities that are naturally temperate, it’s clear we will all need to think more about heat in the coming century.
Sources: US National Oceanic and Atmospheric Administration (NOAA), Climate Impact Lab