The most hot days Basel has recorded by this date.

Hot here means 31.5 °C or above, a level about one summer day in twenty used to reach at this station between 1971 and 2000. The bar has not moved; the number of days clearing it has. Every year is counted to 8 August, so a part-finished summer is never set against complete ones. That threshold is Basel's own. It is not a national standard and it is not comparable with another city's: every figure on this page is measured against this station and nothing else.

11 nights so far that never dropped below 20 °C. No multiple is quoted here. Basel averages about 0.1 a year, and dividing by a base that thin produces a large number and no evidence. 24 of the 42 cities are gated this way.

The hottest day of Basel's year, to the same date. 2026 is the hottest on this record too, by this date, at 39.7 °C. Both the count and the peak are records here, which is not true everywhere: a count and a peak are separate claims and each carries its own rank. The previous best was 39.0 °C in 1952, the dot on the drop line, and a typical summer here peaks at 33.5 °C.

42 cities are measured this way, each against its own record. See them on the map