The Department of Elections has rejected an attempt to recall Mayor Ed Lee until July over a timing issue, which petitioners claim will make it very hard to get on the November ballot. SF has a six month grace period between elections and the start of a recall. The petitioners are claiming that Lee was appointed in 2011, but since he was just reelected and the recall is only referring to the most recent election, the Department is undoubtedly going to prevail here. We've seen this before (notably Portland's Mayor) and I can't see any court ruling otherwise.
Petitioners need about 44,718 signatures to get the recall on the ballot.