Caution: The extension is applicable to only those in the FEMA designated  area.  It isn't a blanket extension for everyone in CA.   By my count only 41 counties were covered in the first extension (to May 15).  A few more were added when IRS came out with the second (to October 16) .  

Guess how many counties California has?   (Hint: Do NOT believe @IRonMaN 's answer.)