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What is the most common birth month?

September, with 11,999 births a day in U.S. records from 2000 to 2014. January is the quietest. By total births, August leads and February trails.

Most births per day

September

11,999 births a day

Most in total: August, 5,540,170

Fewest births per day

January

10,909 births a day

Fewest in total: February, 4,725,693

Gap, busiest to quietest

10%

more births per day in the busiest month

62,187,024 births, 2000–2014

U.S. births, 2000–2014

Birth months, most births per day first

Per-day averages keep February’s 28 or 29 days from deciding the answer. Totals are in the table.

  1. #1September11,999
  2. #2August11,914
  3. #3July11,721
  4. #4June11,474
  5. #5October11,404
  6. #6May11,173
  7. #7December11,171
  8. #8February11,146
  9. #9November11,131
  10. #10March11,125
  11. #11April11,024
  12. #12JanuaryRarest10,909

U.S. births 2000–2014 (SSA). Per-day averages divide by the days each month had, leap days included.

MonthBirthsDaysPer dayRank per dayRank in total
January5,072,58846510,909129
February4,725,69342411,146812
March5,172,96146511,125107
April4,960,75045011,0241111
May5,195,44546511,17365
June5,163,36045011,47448
July5,450,41846511,72132
August5,540,17046511,91421
September5,399,59245011,99913
October5,302,86546511,40454
November5,008,75045011,131910
December5,194,43246511,17176

SSA birth counts compiled by FiveThirtyEight (CC BY 4.0). Descriptive records, not a forecast or an explanation of why births vary.

All 12 months · CSV See every birthday on the heatmap

Most common: September per day, August in total

September averages 11,999 births a day in U.S. records from 2000 to 2014, the highest of any month; August (11,914) and July (11,721) follow. Totals favor long months: August has the most births overall, 5,540,170.

Least common: January per day, February in total

January averages 10,909 births a day, the fewest, about 9% below September. By total births February is last with 4,725,693, simply because it has 28 or 29 days. The table gives both rankings for every month.

Explore every date

Each month links to its full table of dates, and the birthday heatmap shows all 366 at once. The most common birthdays and rarest birthdays rank individual dates. Counts come from SSA birth records compiled by FiveThirtyEight (CC BY 4.0); they describe when births were recorded, not why.

Good questions

What is the most common birth month?

September, with an average of 11,999 U.S. births a day in 2000–2014. By total births, August leads with 5,540,170, helped by its 31 days.

What is the least common birth month?

January has the fewest births per day, 10,909 on average. By total births, February has the fewest, 4,725,693, because it is the shortest month.

What is the rarest birth month?

January, if you compare births per day, which is fair to short months: about 9% fewer a day than September. February is rarest only by total births.

What is the most common birthday?

September 12 has the most recorded births of any date in this data. See the full list of the most common birthdays for every date’s rank.