Weather tracker: Japan swelters as ‘heat dome’ pushes up temperatures

There were scorching conditions across Japan over the weekend, with the 40C threshold breached for the first time in the month of June. A temperature of 40.2C was recorded on Saturday in Isesaki, Gunma prefecture, north-east of Tokyo,which beat the previous June record of 39.8C set in 2011.

Several heatstroke alerts were in place across the region with people taken to hospital for heat-related illnesses, with many older and young people succumbing to heat exhaustion.

High pressure to the east of Japan over the Pacific induced a south to south-westerly airflow that brought warm air up from the equatorial region, which fuelled the high temperatures. High pressure over a number of days contributed to creating a “heat dome”, trapping the warmer air and helping temperatures rise day on day.

There will be little relief from the heat over the coming days for northern and eastern parts of Japan as anomalous daytime temperatures look likely to continue, reaching into the high 30s, thanks to the area of high pressure remaining relatively in situ.

And there will not be much relief at night because temperatures are forecast to remain in some places above 25C – the threshold for Japan’s classification of a tropical night – until the weekend when the heat is expected to subside.

A combination of the effects of climate change potentially altering atmospheric circulation and the extension of La Niña conditions into later this year may be contributing factors to the early summer season high temperatures in the region.

Meanwhile, parts of eastern Europe and Scandinavia are still grappling with heatwave conditions, with temperatures expected to remain 10-15C above the average for the time of year. Tromso, Norway, would usually experience average daytime temperatures of 14-15C but on Wednesday a maximum just shy of 30C could be reached.

A similar picture will occur across the Baltics and eastern Europe during this week into the weekend as high pressure remains in control of this part of the continent, with temperatures hitting the mid- to high 30s. The unrelenting heat will begin to give way next week as temperatures return to the seasonal norm.