This week's violent storms have done little to ease the drought, with fire-risk warnings at level four out of five across most cantons.
MeteoSwiss says the hardened topsoil is shedding heavy rainfall rather than absorbing it, and deeper soil layers stay parched.
Only Ticino and southern Graubünden are better off.
Forecasters warn that a new anticyclone will settle over the country in the coming days, bringing more heat and continued dry weather.
Only weeks of steady, gentle rain would refill the ground — and none is on the horizon.
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