For many of us, mention of the month September might conjure up memories of back-to-school shopping trips, leaves beginning to turn red and golden, or football season gearing up. Thanks to our Party Time database, we now have a new association–in this election year, September is the most partied month of all–see the graph above.

It makes sense. In the universe of congressional fundraising, the third quarter of the year closes at the end of September, with reports due at the U.S. Federal Election Commission on October 15. It’s the last big chance before the election for candidates to strut their money making stuff, showing their opponents how formidable they are by how much cash they’ve collected. Also, Congress adjourned in early October and most lawmakers headed back to their districts to campaign, leaving behind the Washington watering holes where they do most of their fundraising from lobbyists.

Another big spike was toward the end of July, during the Democratic and Republican national conventions. These weren’t for fundraising parties but rather for the festivities that accompany those stately events.

And June is another big partying month, likely largely because that’s when the second quarter for financial reporting closes, on June 30.

Of course as always we must add the caveat this graph may be skewed by the fact we only know about the parties our sources tell us about. There’s no official requirement that these parties be reported, so we rely on what we can get. But the patterns certainly make sense.

Stay tuned in the next several weeks for more big picture analyses from Party Time. Behind the scenes, our Party Time workers have been busy cleaning up the data from the year 2008, working to eliminate duplicates and standardize certain elements. The graph above is part of a work in progress.