[thackney]

You would need to see weekly details in order to discern it.

Here you go. You won't find your assumption like you expect.

U.S. Regular All Formulations Retail Gasoline Prices
http://tonto.eia.doe.gov/dnav/pet/hist/mg_rt_usw.htm

On a monthly basis, a summer run up is not very common.

[E. Pluribus Unum]

Great graph!

[Always Right]

The last four years there have been significant run ups in gas prices from mid-March to end of May of 18-40%.