Gas prices are on pace for the most expensive October on record, with the national average at 4.29 dollars a gallon

American drivers are paying October prices nobody has paid in October before. The national average for a gallon of regular gasoline was 4.29 dollars as of October 23, AAA reported. That is down about 20 cents from a week earlier, and still more than a dollar higher than the same week last year. Diesel averaged 5.75 dollars a gallon, compared with 3.11 dollars a year ago.

This month is poised to set a record as the most expensive October ever for gas prices, following similar records set in August and September of this year, AAA said in its October 22 release.

The cause sits in the crude market. Ongoing instability in the Middle East and concern over oil shipments through the Strait of Hormuz keep pressure on fuel prices, AAA said. Brent crude climbed above 114 dollars a barrel on Friday and settled higher still, at its best level in more than five months, as traders weighed the chance of renewed American and Israeli strikes on Iran and Iranian threats against Gulf energy targets. About a fifth of the world oil supply moves through the strait, and every threat against it shows up at American pumps within weeks.