Geneva's airport has been closed "until further notice" after the Swiss city was blanketed by snowfall overnight.
The airport's website says passengers should stay away for the time being and recommends they check with their airlines to see if their flights are still scheduled for departure.
Airport spokesman Sebastien Leprat said initial targets to re-open around 9 a.m. (0800GMT) had been pushed back by one hour, and that no formal decision had been made to resume traffic.
He said tricky weather conditions across Europe could cause extended delays.
Meteorologist Dominique Stussi of national weather service MeteoSuisse said 13 centimeters (about 5 inches) fell over a three-hour period in the early morning.