Average gas prices reached historic highs this holiday weekend as vacationers hit the road for Labor Day.

Californians are stomaching some of the highest prices for gas nationwide — behind only Hawaii — at an average $4.16 per gallon. Drivers in Colorado, by comparison, pay an average of $3.56.

Filling your tank is even more expensive in San Francisco, where prices average $4.26 per gallon and climb as high as $4.69 in the Mission.

Hurricane Isaac is partly to blame for the steep spike — refinery closures along the Gulf Coast last week reduced the oil supply.

Nearly 33 million Americans — 3.7 million Californians — traveled more than 50 miles away from home this weekend, according to AAA estimates.