It has been very hard to keep track of the number of rockets hitting Sderot today, but my best guess right now is 30: 24 that Ha'aretz counted (plus 24 mortars) at 9:00 PM, plus six more in YNet's updates after that time. (And another two for 32, and another two for 34 if I am counting correctly.)
Four people were injured in Sderot, including a 5-year old girl. And earlier an Ecuadorian kibbutz volunteer was shot and killed by a Hamas Gaza sniper.
Hamas has taken credit for the majority of rockets and mortars as well as that murder, reversing its policy of pretending not to support attacks by its PRC partners.
As far as keeping track on my Qassam calendar, I'll be a bit more conservative for now. Over the past few days a number of rockets were claimed to be shot by Palestinian terror groups in Gaza but I could not find any mention of them landing in the Israeli press.
According to my numbers, this is certainly the worst day for rockets since May but it might end up being the worst ever.
UPDATE: YNet says over 40 rockets on Tuesday. JPost counted 28 plus a Katyusha.
UPDATE 2: 30 already on Wednesday. (Now 50.)