[E. Pluribus Unum]

Here is a third data point from 2004 indicating rising gas prices that year around Memorial Day....

Another anecdote! Who'd have thunk it!

Here's where gasoline/petroleum prices are set:

http://bloomberg.com/markets/commodities/cfutures.html

With your keen observation that prices always increase before Memorial Day you could make a real killing, just like Hillary turned $1000 into $100,000 in ten months in the cattle futures market.

[Always Right]

OK how about this from the Department of Energy

In 2005, from mid-March to late-May prices surged from $1.90 to $2.25. In 2006, from $2.30 to $2.90. In 2007, from $2.40 to $3.30 (and still rising). We have seen prices rise from March 15 to May 30, 18%, 26%, and 37+% the last three years.