NEW YORK (CNNMoney) - The national average of gas stands at $3.81 a gallon. Prices are up 24% from the start of the year. A big culprit behind the surge has been oil. While gas prices typically start to rise at this time of year, $100 oil isn't helping. Based on current oil prices, there is a 33% chance that the national average gas price could hit $4 a gallon in July, said the Energy Information Administration in its April short-term energy outlook. Shell Oil president says the rising demand of oil affects the price and alternatives need to be sought.