Entering September brings the arrival of meteorological autumn in the northern hemisphere, officially drawing the summer of 2023 to a close.
In the UK, the summer was a mixed bag. We started with a fairly pleasant June before entering into a wet and windy July caused by multiple consecutive weekend low pressure synoptic situations. A relatively unusual August followed in which we had two named storms, Antoni and Betty, before a pleasant warm spell.
Meanwhile, Japan has been under the influence of a heatwave over the previous few months, leading to the country breaking records for both the hottest month and the hottest summer since records began in 1898.
After Japan recorded its hottest mean July temperature, with an average temperature anomaly of +1.91C, the country then went on to break the record for the hottest mean August temperature with a mean temperature anomaly of +2.16C. As a result, August 2023 was the hottest month in Japanese meteorological records. The month was so warm that air temperatures in Tokyo were observed to be peaking above 30C (86F) every day of the month, with the lowest daily maximum being recorded at 31.8C on 9 August.
This meant the summer of 2023 was the hottest summer recorded in Japan in the past 125 years. The mean temperature for the season, which is based on observations recorded across 15 locations around the country, reached 1.76C above the seasonal average and beat the previous record from 2010 by 0.68C.
Last Friday, Hong Kong raised a rare typhoon signal 10 storm warning in preparation for Typhoon Saola, which arrived that night. Maximum sustained winds of 121mph (195km/h) were recorded from Saola while it was about 20 miles (30km) away from Hong Kong. The typhoon died down in its passing but not without causing about 460 flights to be cancelled.
With the start of autumn comes the release of new storm names for 2023-24. Each year since September 2015, the Met Office, Met Éireann and KNMI – the national meteorological services for the UK, Ireland and the Netherlands respectively – released an alphabetical list of names for next 12 months; names this year include Agnes, Henk, Olga and Regina.
