Does SFO have a noise limit?
Yes and no.
The website does not specify what exactly exceeding the 65 decibel "limit" triggers.
If nearby cities are subject to 65+ decibels, they may conceivably be eligible to receive federal funding for insulation solutions (which, one assumes, would reduce their property values if they fall into that category). One source said the FAA wants to keep those insulation costs down. Perhaps that's why the mandated decibel limit is 65 using an old formula that underreports the noise.
If you think the 65 dB limit means the FAA and SFO will do everything possible to reduce the noise in our community, you'd be mistaken.
(While we're at it,  as for the often-mentioned noise insulation program.....don't believe the rumors such as "those people were bought off for $20,000", or, "airport representatives went door-to-door to see who wants their homes insulated", et al. The Noise Abatement Office at SFO told me it is VERY difficult to quality for this Federally-funded program; we can figure out for ourselves that if our city were to be labeled as falling into the insulation program category, prices would drop; if you like to breathe fresh air, you'd want windows open, yes? And, among other things, once you sign on the dotted line to accept this insulation, you (and possibly the next owners of your home) give away all rights to complain to SFO again about noise.)