Central Tokyo has seen rain on 34 consecutive days, surpassing the record set in 2019, as persistent weather systems continue to bring rain to the Japanese capital.
Japan’s capital has fallen below its historical record for the number of consecutive days of rain as it has had 34 days of precipitation in a row, the country’s weather agency said.
The streak started on August 27 and was maintained until September 29, beating the previous record of 33 consecutive days from June 27 to July 29, 2019. The long-term precipitation trend at the central station of the Japan Meteorological Agency (JMA) has been confirmed by data from JMA. The data for this study is sourced from Japan Meteorological Agency rainfall records.
The new record does not necessarily reflect heavy rain throughout the day in Tokyo. In Japan, precipitation statistics include any day on which measurable precipitation occurs, even if it is very small. The JMA defines precipitation of less than 0.5 millimeters per day as a “streak” even if it is reported as 0.0 millimeters per day on its site.
The long wet spell has been attributed to typhoons, an autumn rain front and low pressure systems over Japan. Central Tokyo had received about 629mm of precipitation through Sept. 28, about three times the monthly average, Kyodo News reported.
The daily maximum of the current streak was 156mm of rainfall on September 21, the weather agency said, as quoted by the Japanese media. There have also been heavy rains in large areas outside Tokyo, including eastern Japan.
The continuous rains follow an unusually busy weather system in the area. Typhoons have occurred several times during the period in Japan, and seasonal fronts have been present for long periods of time.
Rainfall was also forecast in eastern Japan into early October as a result of weather conditions. Japanese forecasters indicated that the autumn rain front would persist to affect the weather, and that this situation would gradually improve.
The record is significant as the previous record of 33 days was set in 2019 when it rained for 33 days in a row in Tokyo. The new high thus beats the previous record by just one day but is the longest such period since the beginning of observations in 1886.
The pattern is also getting a lot of attention in the context of overall shifts in extreme weather. Climate scientists have determined that a warmer atmosphere can hold more moisture, and therefore the potential for intense precipitation. But the factors of a particular weather phenomenon are multiple interacting factors in the atmosphere.
Heavy rainfall is more likely as climate change can lead to more moisture in the atmosphere, according to a Channel News Asia report titled CNA reported, while this year’s El Niño is also affecting wind, pressure and cloud patterns in parts of the world.
The abnormal rain has made for weeks of instability for residents and businesses in Tokyo, as the city typically gets cooler fall weather. Additional rainfall in early October could push the record even higher.
