Oil prices have risen above $55 a barrel as traders look to the key summer driving season in the US.
Experts warn US holiday demand will eat away at fuel stockpiles
With US demand for crude always high in the summer months as Americans take to the road for their holidays, analysts inevitably worry about US stockpiles.
The start of hurricane season in the southern states of the US is another concern - last year numerous oil facilities were damaged.
Oil prices are now 40% higher than this time a year ago.
Other continuing upward pressures on crude are the ongoing situation in Iraq, and China's burgoning economy.
In Monday morning trading in Singapore, a barrel of US light crude was trading at $55.31, up from Friday's $55.03.
Commentators said analysts were remembering the damage caused in the Caribbean and US last year by Hurrican Ivan.
Last September, Hurrican Ivan caused more than 30 million barrels of lost oil production in the Gulf of Mexico.
"The gloomy forecast for this hurricane season will put the market more on edge and will increase price volatility, even if this year doesn't deliver a replay of Ivan's damage," said Houston-based Energyintel analyst John Sullivan.
Although there is no immediate hurricane forecasts, combined with peak petrol consumption in the US, the start of summer inevitably gives oil traders cause for thought.