Extreme Temperature Diary- Wednesday March 17th, 2021/ Main Topic: Cherry Blossoms Signal A Rapidly Warming Climate Again this Year

The main purpose of this ongoing blog will be to track planetary extreme or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉

Main Topic: Cherry Blossoms Signal A Rapidly Warming Climate Again this Year

Dear Diary. For years we’ve been seeing weather and climate headlines stating that the cherry blossom bloom in Washington DC has been occurring much earlier than was typical before the turn of the century. Yesterday record temperature researcher Maximilliano Herrera let me know that in Japan, that gifted to DC its cherry trees, a peak bloom occurred, which may be the earliest during the spring in about 1,200 years. Here are the notes I saw:

I’ll let you know if these stats and ominous looking charts are legit once outlets like the Washington Post confirm them.

It hasn’t been too long since Washington DC and Kyoto Japan saw a very early record bloom. Here is more from a 2017 Washington Post article, the year we saw the last record early cherry bloom:


Capital Weather Gang Analysis

Japan’s cherry blossoms signal warmest climate in more than 1,000 years

People take pictures of cherry blossoms in full bloom along a river in Tokyo on April 4. (Franck Robichon/European Pressphoto Agency)

By Jason Samenow April 4, 2017 at 9:06 a.m. PDT

For more than 1,000 years, emperors, aristocrats, governors and monks have chronicled the flowering of Japan’s famed cherry trees in the city of Kyoto. But bloom dates have shifted radically earlier in recent decades, a sure sign that the region’s climate is warming and warming fast.

Yasuyuki Aono, a professor of environmental sciences at Osaka Prefecture University, has assembled a data set that compiles blossom-flowering dates in Kyoto all the way back to 800 A.D. It shows a sudden and remarkable change in the past 150 to 200 years.

From roughly 800 to 1850, the blossom flowering time was fairly stable. While the bloom dates bounced around quite a bit from year to year during April, the long-term average hovered between April 10 and April 17 (the 100th to 107th day of the year).

Data plotted by Zeke Hausfather. <a href=”http://atmenv.envi.osakafu-u.ac.jp/aono/kyophenotemp4/”>Data via Yasuyuki Aono</a> .

But from 1850 to present day, the flowering has surged toward earlier dates at the rate of about one week per century. Consider that in 1850, the average flowering date was around April 17; now, it’s closer to April 6.

The bloom dates have advanced as March temperatures in Kyoto have rapidly risen. While there are different environmental factors that influence the flowering dates, usually the warmer it is in March, the earlier the cherry blossoms bloom.

Aono said the estimated temperature had warmed 6.1 degrees (3.4 Celsius) in Kyoto since 1820. In his temperature reconstructions dating back as far as 800 A.D. posted online, no other period was as consistently warm as the present.

The shape of the trend line through the blossom flowering dates resembles a hockey stick — with a flat handle but sharply sloping blade. Indeed, multiple studies documenting temperature changes over the past 1,000 to 2,000 years have taken on a similar shape, reflecting a relatively stable climate through the mid-1800s, and a quickly warming one ever since.

Perhaps no long-term temperature reconstruction is more famous than the original “hockey stick” chart published by Penn State climate scientist Michael Mann nearly two decades ago. It showed that temperatures in the 20th century were warmer than any time in at least the past 1,000 years.

Mann was not the least surprised when presented with the Kyoto data. “Kyoto is just one location on the planet,” he said in an email. “But the large-scale warming of the past century is so distinct and widespread that it is  increasingly evident from diverse records all around the globe.”

Both Kyoto’s cherry tree flowering and temperature data suggest that its climate is warmer than it has been in at least a millennium.

Interestingly, recent trends in Kyoto’s cherry blossom flowering dates are very similar to those in D.C.

In 1912, Japan gifted Washington 3,000 cherry trees and, since 1921, the National Park Service has kept a record of their peak flowering dates.

Data from National Park Service for Washington and Yasuyuki Aono for Kyoto.

Washington’s peak bloom date has advanced about five days, from April 6 to April 1 between 1921 and 2017. At the same time, Kyoto’s peak bloom date has moved forward from around April 12 to April 5.

Just as warming March temperatures are likely to blame for the earlier bloom dates in Kyoto, the same holds true in Washington. Since 1921, Washington’s March temperatures have warmed at the rate of about 2.8 degrees per 100 years.

In both Kyoto and Washington, the warming trends and earlier blooms are most likely due to a growing urban heat island effect and increasing concentrations of greenhouse gases in the atmosphere.

Headshot of Jason Samenow

Jason Samenow Jason Samenow is The Washington Post’s weather editor and Capital Weather Gang’s chief meteorologist. He earned a master’s degree in atmospheric science and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association. Follow

Here is more climate and weather news from Wednesday:

(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)

Now here are some of today’s articles and notes on the horrid COVID-19 pandemic:

(If you like these posts and my work please contribute via the PayPal widget, which has recently been added to this site. Thanks in advance for any support.) 

Guy Walton “The Climate Guy”

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