With the Olympic Games opening ceremonies less than a week away, all eyes will be on the weather forecast.
Athletes try to train in conditions that will be similar to what they will face in Japan, but we all know that sometimes Mother Nature doesn’t always play nice.
Pressure has been mounting for years as the concerns of heat in the region loomed on the Games.
Looking back to all the Olympic Games dating to 1984 in Los Angeles, Tokyo’s average high temperature is warmest and it is also the wettest for the two weeks of competition.
The average temperature combined with humidity in Tokyo has the potential to make these games feel even hotter than Atlanta and Athens.
Tokyo is also threatened by typhoons, which can bring torrential rain, high winds and flash flooding. The threat of typhoons lasts from May through October but usually peaks in August and September.
It’s so hot, some events are far removed from the city
In July 2018, Kumagaya (located about 40 miles northwest of Tokyo) recorded Japan’s hottest national temperature of 106 degrees F. A month later, this was matched again in the central city of Hamamatsu.
In early 2019, the International Olympics Committee both acknowledged and addressed some of the hot weather concerns by moving the marathon and various outdoor events to the cooler northern city of Sapporo - which is located about 500 miles north of Tokyo.
Here, temperatures can be as much as 40 degrees cooler than Tokyo during the period of the Games.
The average high temperature in Sapporo is in the upper 70s for this time of year, similar to places like Boston, Portland and Minneapolis.
But just like these US cities, Sapporo isn’t exempt to warm spells either. “In 2019, Sapporo had a stretch in late July and early August where eight out of nine days topped 90 degrees,” said CNN meteorologist Taylor Ward.
Tokyo’s main summertime weather feature brings torrential rains
Tokyo is affected by the Mei-Yu Baiu front, or the plum rains, in late June and early July. This semi-permanent front slowly pushes northward and hits much of East Asia from May through July.
Areas along this front can experience heavy rain and flash flooding for a few weeks.
This year’s rains caused a deadly mudslide in Atami that left 2 people dead and more than 20 missing. Atami is about 60 miles southwest of Tokyo.
The Mei-Yu Baiu front typically lifts north of Tokyo by mid-July and ushers in the hottest temperatures and most oppressive humidity of the year from mid-July through August.
While the average high temperature in Tokyo during the Olympics is 86-88 F, high temperatures frequently reach the mid 90s and in recent years have approached 104.
Not only are temperatures warm, but humidity is extremely high. “Tokyo can many times experience dewpoints in the mid to upper 70s this time of year, comparable to places like New Orleans and Miami,” said Ward.
Athletes and the heat
For USA track and field athlete Gail Devers, heat doesn’t seem to be an issue. “I’d want it hot and comfortable, because the hotter for me, the better it helps your muscles to warm up quicker,” she says.
But for other athletes, like long-distance runners, the heat can be dangerous, if not deadly.
Combining this heat with very high humidity has led to several deadly summer heat waves across Japan in recent years.
These conditions could put extreme strain on athletes in outdoor venues during the Olympics.
Japan and climate change
These recent summer heat waves that have impacted many areas across East Asia and the globe can be attributed, in part, to climate change and global warming.
As our planet warms due to increasing greenhouse gas emissions, our climate is changing in many ways. One of those ways is increased heat waves – longer duration, more intense and greater frequency. Recent scientific studies have attributed more extreme heat waves in Japan to climate change, and note that they are becoming increasingly likely as the planet warms.
Had the Olympics taken place last year as planned before Covid-19, the weather might have offered a helping hand.
Much of the summer was on the unusually cool side as the region’s famed rainy season extended well into July, helping keep some of the heat at bay.
Rain or shine, the Games must go on.