Originally Posted by
Palal
There are no lounges in SFO with showers, but there is a facility called "Freshen Up!"
There is the Singapore Airlines SilverKrisLounge that has showers. With a departing *A international business ticket you should have access to it (or if you were *Gold). Unfortunately, the hours are fairly limited for your flight times (opens around 9am, closes around noon:30, opens again about 8:30pm which is pretty useless for a 9pm departure).