Pollen season is now underway – according to the Swiss Allergy Centre.
Grass pollen was detected early in April, says the forecaster Meteosuisse, but it was then held back by the cold snap.
But overall, vegetation is around two weeks ahead of schedule. The Allergy Center says hay fever sufferers – about one in seven people – will now start feeling the effect.
Most of those with allergies do react badly to grass pollen.