I got bored, noticed that Facebook points out when all of my FB friends’ birthdays are by month so I made a quick histogram in Excel. I was a little surprised that the birthday months are rather even distributed.
My question to this was then, “How does this compare to the national distribution?” Luckily, that was an easy Google search and I found this old gem on WikiMedia:
There is some qualitative similarity in that February is the low month. Although with 10% fewer days than the other months, there’s a statistical reason for the dip. Summer also seems to be prime baby having time. I guess those first cold days of late fall/winter and the holidays have some magic in them.