It was an unusually hot day at the NBCN weather station in Binningen. The minimum temperature was 17.5 °C, the maximum reached 32.6 °C, and the daily mean was 24.5 °C. This qualifies as a hot day, which is defined as a day with a maximum temperature of at least 30 °C.

Looking at the last 30 days, the average air temperature was 22.66 °C. The lowest temperature recorded in that period was 10.3 °C, while the highest was 38.1 °C. There were 26 summer days, 13 hot days, and 1 tropical night, where the temperature did not fall below 20 °C overnight.

For the current season up to this date, the day of interest stands out. Its mean temperature ranks second among all September days on record, while its maximum temperature ranks 17th. Compared to the last 365 days, the maximum temperature ranks 36th and the mean temperature ranks 42nd.

The hottest September day ever recorded at this station occurred on 6 September 1949, with a maximum of 35.0 °C. The second hottest was 12 September 1947 at 34.7 °C, followed by 19 September 1947 at 34.5 °C. The fourth and fifth hottest days were 5 September 1949 and 3 September 1962, both reaching 34.1 °C. These top five values are shown in Table 1.

In summary, the past day’s maximum temperature of 32.6 °C ranks 17th among all September days in the station’s history, confirming that while not record-breaking, it was still an exceptionally hot day for this time of year.