LOCARNO - The temperature at Locarno-Monti has failed to fall below 20 degrees on 47 nights this summer, the most tropical nights ever recorded at a Swiss station. Lugano stands at 44. In the heat summer of 2003, Locarno managed 42 and Lugano 33, Luca Panziera of MeteoSwiss said on Monday. Until the 1980s the yearly count was often under ten.
The southern side of the Alps is the only part of the country still under a level-four heat warning, in force until Friday evening. Panziera said the pattern is unlikely to break before 17 August, apart from a possible brief thunderstorm. Sustained rain is not in the forecast. From next week the most likely shift is three to five degrees off the worst of the heat, which would still leave a level-two or level-three warning, not an autumn.
Why the night figure matters more than the poster
The film festival is still on the piazza this week. The climate number will still be here when the screen comes down. A tropical night means apartments do not cool, hospital admissions change character, and the lake path at midnight is a coping strategy. Our July note on Lugano moving its day to the early morning was an early version of the same fact.
Lugano and Locarno are the only monitoring stations with counts this high. That is geography, lake and foothill, and it is also the reason Ticino's summer is no longer a mild exception to a Plateau heatwave. The Plateau had its own record on 30 July in Basel.
What forecasters will and will not promise
Panziera was careful about the week after 17 August. Uncertainty rises, a shower is possible, and nothing on the charts looks like the end of summer. For readers in the valleys, the practical line is the warning level, not the festival photograph. Forty-seven nights above 20 degrees is the record. It is also a description of how people in Locarno have been sleeping.