If it seems like you have a lot of birthdays to celebrate in the months of July, August and September, you aren’t crazy. These are the most common months for birthdays in the US.

Each month there are 300,000-400,000 new babies born in the US. These three months in particular have about 10-20,000 more births than other months, generally speaking. August generally has the most births.


Why isn’t childbirth spread throughout the year evenly? There are a quite a few different guesses, and they may all have some truth.

Some say that when things get colder, people spend more time inside, which leads to more sex. If more children are born in August, that means the process started in December or January.

But this pattern does not follow in other parts of the world. In parts of Europe, births peak in spring, which is the opposite of what happens here.

Others have pointed to research suggesting that the season of your birth affects personality. Some research suggests that those born in winter are at higher risk for mental health disorders like depressions and seasonal affective disorder. Birth weight, health and defects may also be affected by the season. But it is unlikely that this data is accepted on the scale that birthrates across the country would be influenced.

Are We More Fertile In Winter?

There isn’t any evidence to suggest that fertility changes with weather or seasons. Consult with Dr. Fisch about timing and other concerns with fertility.

Some interesting facts:

  • In 2014, 3.98 million new babies were born in the US.
  • The most common birthday is September 16th , even though there are more birth in August on average.
  • December 25th and Feb. 29th are least common birthdays.
  • Birth rates for women over 30 are on the rise in recent years.
  • Births are more common Tuesdays and least common on weekends.