Gas prices are now lower than at this time last year. Could they fall below $3 a gallon in the months ahead?

Gas prices on Thursday were slightly less on average than they did one year ago — with a slim one-cent margin — but experts say there could be cheaper gas in the weeks and month to come.

Thursday’s national average for a gallon of gas was approximately $3.33, AAA said. That’s down from $3.34 this time last year, and significantly lower than the record high of $5.01 a gallon recorded in mid-June.

Six months after drivers were snapping photos of high prices at the pump, gasoline-industry experts say the downward...