This blog has been medically reviewed by William Thompson III, MD, gynecologic surgeon and obstetrician, at Allina Health.
Maybe you’re a parent-to-be trying to plan your baby’s birth month for a specific reason, like taking time off work during the summer months or avoiding winter germs with a newborn. Even if you’re following the healthy steps to prepare yourself for pregnancy and monitoring your cycle and the calendar, the chances are still good that your baby could arrive during one of the most popular birth months. And ultimately, every month is a great month to welcome a beautiful new baby!
Below, we will share what the most common birth month is, the most common birthdays, and the reasoning and data behind it all.
Connect with a trusted provider at The Mother Baby Center to get expert care and support for your birthing journey.
What is the most common birthday month?
There can be so many unknowns – and surprises – when you’re trying to conceive and plan for a baby. Will your baby be born in the spring when the tulips bloom? Maybe your newborn will arrive in time for the first snowfall of the season. Or maybe they will have the same birthday as you!
Wondering how to calculate your pregnancy weeks to months, learn more here.
Many people wonder, what is the month with the most birthdays? Despite all of your planning, the odds are your baby will arrive in the summer. August is the most popular birthday month, followed by July. According to 2023 data collected by the Centers for Disease Control and Prevention (CDC), more than 322,000 babies were born in August and nearly 312,000 in July. That’s more than 10,000 babies arriving each day in the U.S. during those two months!
Count back nine months and that makes October and November the most popular months to conceive. Researchers think biological factors in colder months, like an increase in male fertility and higher ovulation rates, as well as people spending more time indoors, are all factors leading to the peak birth months the following summer and the least popular month for birthdays in February.
The most popular birth months in the U.S. (2023)
- August
- July
- October
- September
- June
- May
- January
- March
- November
- December
- April
- February
Once pregnant, learn more about when to take birthing classes.
What is the most common birthday?
Since August is the month with the most births, the most common birthday must also be in August, right? Not exactly. The most common birthday is actually September 9. In fact, nine of the 10 most common birthdays in the U.S. are in September (and zero are in August!).
The most common birthday dates were determined from data from the National Center for Health Statistics and the Social Security Administration and analyzed by statisticians. (Note: The data for this analysis is from 1994-2014. It is the last known report available for this information and may not represent current trends exactly.)
The reason the most common birthdays are in September is simply because that’s how the numbers added up on the specific date, according to the statisticians. The difference between the most common birthday and other popular birthdays is often very small.
The most common birthdays in the U.S.
- September 9
- September 19
- September 12
- September 17
- September 19
- July 7
- September 20
- September 15
- September 16
- September 18
If you’re planning for your own little one, explore our first trimester to-do list to help you prepare for a healthy pregnancy journey.
What is the rarest birthday month?
The rarest month to be born is February. Since it’s the shortest month with only 28 days (or 29 during a leap year), there are fewer days to count. Just under 271,000 babies arrived in February 2023 – that’s 51,000 fewer babies than arrived in August of that same year. April is the next most uncommon month to be born – about 279,000 babies were born in April 2023 in the U.S.
Unsurprisingly, February 29 is the most uncommon birthday in the U.S., since it officially only happens once every four years. There is a 1 in 1,461 chance of being born on February 29 – and less than 0.1% of the world’s population has that birthday!
The rarest birth months in the U.S. (2023)
- February
- April
- December
- November
- March
- January
- May
- June
- September
- October
- July
- August
Why is there a most common month to be born?
There are several theories about why there is a most common birth month, ranging from biological to cultural. And with August and July being the most common birth months, that means winter is a good time to make babies – November and December are the most popular months to conceive.
Research has suggested male fertility is higher in colder months, with improved sperm quality. Some think there’s also an evolutionary drive for humans (and other species) to conceive in the winter and give birth in the spring or summer. Also, cold weather encourages couples to spend more time together indoors, which can lead to more opportunities for intimacy. Add in the holiday season, parties, extra time off of work, and more time with family and you can see how nine months later there will likely be a baby boom!
For healthy couples in their 20s and early 30s, around 1 in 4 women will get pregnant in any single menstrual cycle, according to the American College of Obstetricians & Gynecologists. So even if everything is perfect, pregnancy is still not achieved most of the time. But don’t be discouraged! On average, 85% of healthy couples under age 35 conceive within one year. However, choosing the exact month you’re aiming for could be trickier than you think.
“Some of our patients are trying to plan the month they get pregnant and we support them every way we can, but this can be hard to do,” said Dr. William Thompson III, gynecologic surgeon and obstetrician, at Allina Health. “Sometimes pregnancy happens on the first try, or it might take a year or more. In some instances, pregnancy requires treatments with a fertility specialist. We want all our patients to feel supported and hopeful throughout their journey with us and know they have received the best care – whatever month their baby arrives.”
Find a trusted provider at The Mother Baby Center
Whether your baby arrives in August or February, or any other month, our trusted providers at The Mother Baby Center are ready to care for you both. Every month of the year we provide mothers and babies with expert, personalized care from our diverse team of highly trained health professionals in obstetrics, midwifery, maternal-fetal medicine, neonatology and pediatric medical and surgical sub-specialty services.