The average price of gas in Ontario is expected to jump to $138.9/litre tomorrow. We’re back to hitting record highs with gas prices – today gas cost $137.9/litre – the highest price since July 2014. Why is gas so high? Factors include the high cost of oil, the value of the Canadian dollar and HST. The bad news is that the price of gas will continue to rise over the summer. Might wanna re-think those long drives to the cottage.