Gas prices are expected to jump 6 cents/litre at midnight in the GTA

You might want to fill up your tanks before the clock strikes 12.

Average prices in the Greater Toronto Area are expected to jump as much as six cents/litre,from 115.9cents/litreto 121.9cents/litre, at midnight tonight, according to GasBuddy.com

"All of our prices have everything to do with the stock market for gasoline in New York and that price went up over 15 cents a gallon [Monday]," said Dan McTeague, senior petroleum analyst at GasBuddy.com.

McTeague said he hasn't seen gas prices like this since October 4, 2014.

"Compared to that time in 2014, the Canadian dollar was much stronger, and of course we didn't have a carbon tax [or]a cap-and-trade tax, sothose two factors alone account for an 11-cent difference between what we are paying today and what we are paying back when we last saw it," said McTeague.

Winter to summergasoline

The increase is demand in the U.S., as well as the shift from winter-blended to summer-blended gasoline, according toMcTeague.

Warmer weather can lead to gasoline becoming volatile or evaporating into the environment,McTeaguesaid.

"It's important for refineries, through a federal mandate, that they provide additives, change the blend and the composition to stabilize the gasoline under higher temperatures," he said.