If your birthday is in July, August, or September then - congratulations!
You're painfully common.
We're about to start entering baby season. September is the busiest month for births, but it all starts ramping up from now - as the below graph by the Daily Viz shows:
If you were born on 9 September, you're officially born on the most popular birthday.
The least popular is Christmas, 25 December - possibly because no one wants a Christmas day delivery.
A Harvard study into the matter also showed that the 1 January, New Year's Day, was uncommon, presumably for the same reason.
While their findings differed slightly from the above graph...
... The trend is roughly the same.
There were notably more conceptions in the winter as births in the summer and autumn were the most popular.
A 2013 study from the Massachusetts Institute of Technology suggested that the variation in birth rates were accounted for by planned pregnancies.
In addition, the quality of sperm varies with seasons.
A study of nearly 6,500 human sperm samples in 2013 found that fertility increased for samples taken in winter and spring, which could contribute to the increased birthrate in summer.
Personally, we think it's those chilly winter nights.