"We've got rain moving in from the west through the day," he said. "It's just got into the London area now and the next couple of hours there's outbreaks of rain coming up from the west and south-west."
He said most of the rain would be light and drizzly, adding: "This light and patchy rain could cause some disruption."
And the wet weather could continue throughout the week, in contrast with last week's fairly bright weather. Last Thursday spectators enjoyed soaring temperatures of up to 28C at the All England Club. "It's quite an unsettled week. There will be more outbreaks tomorrow and outbreaks which will continue for much of the day really."
Murray will be aiming to repeat his Saturday night victory at Wimbledon, after making history with the latest finish the tournament has ever seen. Fans feared the match against Marcos Baghdatis would have to be finished today, but the Scot powered through to victory just after 11pm.
Cilic beat the clock himself with a five-set win over Sam Querrey which went to 17-15 in the decider. The Croatian is on an eight-match winning streak on grass after benefiting from David Nalbandian's moment of madness in the Aegon Championships final at Queen's Club. Cilic also ousted Murray in the fourth round of the US Open in 2009, but Murray got his own back the following year when he beat him to reach his first Australian Open final.