Meteorological authority declares short season in several regions as temperatures remain high across country
Excessive heat has remained a headline story across Japan over the past few days. An area of anomalously high pressure nearby in the Pacific Ocean has moved little over the last week and continues to fuel record-breaking temperatures. The city of Isesaki recorded a temperature of 40.2C, the highest ever in the country for June. More seasonal temperatures are not expected to return until next week.
June is considered to be well within the rainy season in Japan’s central and southern districts; climatologically the generally cloudier and wetter conditions, with suppressed temperatures, continue well into the first fortnight of July. However, the Japan Meteorological Agency declared an early end to the season this week for many areas, including Tokyo’s Kanto-Koshin region, where the season terminated more than three weeks before schedule, the earliest in several decades. For the southern regions of northern Kyushu, Shikoku, Chugoku and Kinki, where the season began between 11 and 13 June, this represents about a fortnight of rains, when typically it can last about six weeks.
(SOURCE) https://www.theguardian.com/weather/2022/jul/01/japan-rainy-season-ends-early-amid-heatwave