Tokyo Summers See No Warming Trend In 27 Years…Hachijojima Pacific Island No Warming In 80 Years

11 September 2021 0 By Bambam

By Kirye
and Pierre

The meteorological summer 2021 has ended and the mean SUMMER annual temperature data for Tokyo and Hachijojima island are now available from the Japan Meteorological Agency (JMA).

Today we plot Tokyo’s mean summer temperature going back 27 years. There’s been no rise over the period. In fact the plot shows a slight cooling trend:

Data source: JMA

Also an volcanic island – Hachijojima – belonging to Tokyo located in the middle of the ocean 287 kilometers south of Tokyo saw a mean summer temperature this year of 24.3°C. For Hachijojima we plot the summer mean data  going back more than 80 years, to 1940:


Data source: JMA


The rural features of the island Hachijojima make it ideal for eliminating the urban heat island effect that we would expect to find in the huge sprawling metropolis of Tokyo. As the summer mean temperatures show, there’s been no summertime warming since 1940. The climate there in terms of temperature is no different than it was in 1940!

The hottest summers were decades ago.

As we mentioned earlier, the urban heat island effect is clearly visible when we compare the data from Tokyo and Hachijojima:

Tokyo’s maximum daily temperature has been rising much faster than that of Hachijojima. It’s not CO2.