You’ve probably noticed that the world is on fire right now, and that includes Japan.
Having just dealt with horrific rain and floods that led to hundreds of deaths, it’s now burning in a heatwave that the Japan Meteorological Agency (JMA) has declared to be a natural disaster. As dozens die, temperature records just keep getting broken.
On Monday, temperatures peaked at 41.1°C (106°F) in Kumagaya, a town close to Tokyo, smashing the previous national all-time high by 0.1°C (0.18°F) back in 2013.
Temperatures have lingered in the low-40s in recent days, and as picked up by Earther, around 70 percent of JMA’s weather stations have recorded temperatures above 30°C (86°F). As of July 22, the highs in Kyoto have been above 37°C (99°F) for nine consecutive days, a first since records began in 1880.
On July 20, as pointed out by an NHK meteorologist, multiple cities – including Tokyo itself – have reached all-time highs. The heat indices, which take into account relative humidity to reveal what the temperature actually feels like, peaked at a staggering 47°C (117°F) in Fukuoka on the western isle of Kyushu.
As reported by BBC News, more than 22,000 people in the country have been admitted to hospital suffering from heatstroke. The heatwave is currently in its third week, and at the time of writing, 77 people, from the very old to the very young, have died as a result.
“This heat is a threat to life,” a JMA official told Kyodo News. “We recognize it as a natural disaster.”
The heatwave is being caused by something called a heat dome. As explained by the National Oceanic and Atmospheric Administration (NOAA), this is when a high-pressure zone gets stuck in the upper atmosphere. In this case, the blockage is thanks to a warped jet stream that's not doing its atmospheric circulation job properly over the archipelago.
This zone then acts as a cap, which prevents hot air from escaping. Consequently, this warm air heads back to the surface, and takes on more heat in the process.
There is, of course, a bit more to the story than that.