June 21, 2026, was an exceptionally hot day at the NBCN weather station in Binningen. The minimum temperature was 19.3 degrees Celsius, the maximum reached 36.2 degrees, and the average temperature settled at 26.9 degrees.

Over the last 30 days, the average temperature was 20.75 degrees, with a minimum of 9.2 degrees and a maximum of 36.2 degrees. This period included 21 summer days and 11 hot days, but no tropical nights. For the current season, this day’s maximum temperature ranks first among the last 365 days, and its average temperature ranks fifth. Looking at all years for this season, the hottest day on record for June remains June 27, 1947, with a maximum of 38.4 degrees. The hottest day for this month specifically is also June 27, 1947. The top five hottest June days are listed in Table 1. The maximum temperature of 36.2 degrees on June 21 ranks as the fourth highest ever recorded for the month of June.