This morning, at 10:53 AM local time in Tokyo, the temperature was a sweltering 95.2 F (35.1 C) and climbing…
For six days running thermometers in that city have been above 95 degrees F (35 C). That’s the longest unbroken string of 95 degree + highs Japan’s capital has experienced since record-keeping began 140 years ago in 1875. In other words, parts of Japan are experiencing never-seen-before heat.
All told, recent days have seen fully 25 percent of Japan’s cities and towns hit temperatures above 95 F. It’s a heat that sinks bone deep. That gets into the blood. That makes it hard to keep going outdoors. A heat that causes injury and, sometimes, death. And over this summer more than 35,000 people have been hospitalized throughout Japan due to heat injury. Of those, more than 850 have remained hospitalized for three weeks or more. And from this grim tally 55 have now lost their lives.
Hot Ocean Waters Breed Heat Domes
The record hot air temperatures have come on due to a combination of factors. First, the ocean around Japan is abnormally warm. Recently, near-Japan sea surface temperatures have ranged from 2-5 degrees Celsius above established averages. That’s excessively hot water, especially when one considers that El Nino will typically draw the warm waters south and eastward. But this year is not at all typical with unusual-to-record heat now ranging much of the Pacific Ocean basin.
(Extreme sea surface temperatures and a heat dome high pressure system are setting the stage for record heatwaves and tragic heat injuries in Japan. Ocean temperatures in the region have ranged up to 5-6 C above average for this time of year. Image source: Earth Nullschool.)
Near Japan, the added ocean warmth lends both heat and humidity to the air about the archipelago land mass. A combination that can push wet bulb readings into ranges that are ever more difficult for human bodies to manage.
Concordant with the exceptionally hot waters surrounding Japan is a heavy heat dome high pressure system dominating the atmosphere above it. This heat dome, as with many weather systems under the regime of human-caused climate change, has been doggedly persistent. Setting up an excessively long-lasting period of record heat that has now continued off and on for weeks.
Multiple Heatwave Mass Casualty Events for Record Hot 2015
Japan joins India, Pakistan, and the Persian Gulf Region as locations experiencing heat capable of producing mass casualty events this year. In India, more than 3,000 lost their lives due to high heat and humidity during late May and early June. In Pakistan, more than 1,500 died due to the heat even as hospitals were overwhelmed by related injuries. And in Iran last week, wet bulb temperatures rocketed to a stunning 34.7 C.
Under human-forced climate change it’s a sad fact that heatwaves proliferate. We are now four times more likely to experience a heatwave on any part of the globe than we were back during the 1880s. Before our fossil fuel burning warmed the global climate by 1 degree Celsius. And as maximum temperatures and humidity push toward and past the wet bulb limit of 35 C, we are unfortunately likely to see more and more of these heatwave mass casualty events.
Hat tip to Colorado Bob