The start of play in the US Open men’s tennis semifinals is being delayed by rain.

A storm hit Flushing Meadows mid-morning Saturday, dumping heavy rain that continued past 11am local time, when Olympic champion Andy Murray was supposed to begin his semifinal against 2010 Wimbledon runner-up Tomas Berdych.

Saturday’s schedule also includes the other men’s semifinal, between defending champion Novak Djokovic and fourth-seeded David Ferrer, and the women’s final, between 14-time major champion Serena Williams and No.1 Victoria Azarenka.

The US Open is the only Grand Slam tournament that schedules two men’s semifinals on Saturday. If both aren’t completed on Saturday, the final can’t be played on Sunday and needs to be delayed until Monday – which has happened in each of the past four years.