Historical look at cool March

Here's a historical comparison ...

Of how cold this march stacks up to the historical record.

Each of Naples winter-worthy days is represented on the calendar chart above by a dot.  This year we had 15 green dots (in which the daily high didn't rise above 70) and one day -- the blue dot -- in which the daily high didn't rise above 60 degrees.  

This winter is highlighted by the thin red horizontal line across the bottom of the page. As you can see, we sometimes get cool days even in April, but they become increasingly scattered, each one, i.e. green dots, threatening to be our last hurrah.

Any guesses what happened on the most recent red dot (January 11, 2009)?