Do winter babies arrive later?

There's a rumor that winter babies go a little later than summer babies. In the table below, the "2/3 Range" means that 2/3 of all babies born during this month were between those days. 280 days exactly 40 weeks.

The page shows only babies born in the United States, and excludes all inductions.

Month	# samples	2/3 Range	Average
January	740	266-286	276.1
February	645	270-286	277.1
March	644	269-286	277.3
April	637	269-286	277.5
May	638	268-286	277.2
June	693	270-286	277.8
July	643	270-287	278.3
August	614	268-287	277.5
September	663	269-286	277.5
October	630	270-287	278.1
November	588	268-287	277.4
December	601	268-287	276.9