October 13 is the second-least-common October birthday in the U.S. records from 1994 through 2014. Its commonness rank is #317 of 366, where #1 means most common. It is less common than most dates, but not as rare as Halloween.
The sample contains 226,792 October 13 births: 0.265% of all recorded births, or about 1 in 378. Those are historical birth records, not the number of living people with this birthday.
October 13, beside other birthdays
Average recorded births each time a date occurred, 1994 through 2014.
- Commonness rank
- 317 / 366
- Share of recorded births
- 0.265 %
- Recorded births
- 226,792
Bars start at zero. Rank 1 means most common and uses total births across all 366 dates. The bars use births per actual occurrence; February 29 appeared five times, while the other dates appeared 21 times.
Check October 13 and compare with a friend →How does October 13 compare with nearby birthdays?
The October guide compares every date in the month. October 13 ranks 30 of 31 there. The table below adds its overall rank and selected nearby dates, with November 13 for context.
| Date | Recorded births | Commonness rank | Birth share |
|---|---|---|---|
| October 6 | 238,783 | 115 | 0.279% |
| October 12 | 232,009 | 217 | 0.271% |
| October 13 | 226,792 | 317 | 0.265% |
| October 14 | 234,977 | 168 | 0.274% |
| October 20 | 233,282 | 193 | 0.272% |
| November 13 | 226,740 | 318 | 0.265% |
October 13 occurred 21 times in this baseline. It averaged 10,799.6 births per occurrence across those dates. That historical average does not predict the next October 13.
Is the difference just a weekday effect?
Daily birth counts differ by weekday. To make a closer comparison, we used the separate SSA series from 2000 through 2014 and compared each October 13 with eligible dates one and two weeks away in the same year. All share its weekday.
October 13 had 4.3% fewer births than the combined comparison. It was lower in all 15 observed years. Restricting the window to one week gives -3.8%; two weeks gives -4.8%. These are differences relative to the chosen dates, not explanations of why births differed.
| Year | Weekday | Recorded births | Nearby mean | Difference |
|---|---|---|---|---|
| 2000 | Friday | 11,723 | 12,655.8 | -7.4% |
| 2001 | Saturday | 8,659 | 8,830 | -1.9% |
| 2002 | Sunday | 7,416 | 7,716 | -3.9% |
| 2003 | Monday | 11,455 | 12,163.8 | -5.8% |
| 2004 | Wednesday | 13,069 | 13,219.5 | -1.1% |
| 2005 | Thursday | 12,922 | 13,408 | -3.6% |
| 2006 | Friday | 12,628 | 13,589.5 | -7.1% |
| 2007 | Saturday | 8,756 | 8,878 | -1.4% |
| 2008 | Monday | 11,616 | 12,529.5 | -7.3% |
| 2009 | Tuesday | 12,941 | 13,468.8 | -3.9% |
| 2010 | Wednesday | 12,358 | 12,827.3 | -3.7% |
| 2011 | Thursday | 12,201 | 12,620.8 | -3.3% |
| 2012 | Saturday | 8,153 | 8,380 | -2.7% |
| 2013 | Sunday | 7,172 | 7,337.3 | -2.3% |
| 2014 | Monday | 11,241 | 11,990.5 | -6.3% |
We exclude actual and standard observed federal holidays, Christmas Eve, December 26 and the day after Thanksgiving from the comparison dates. All 60 candidate control dates in this comparison were eligible; none fell on an excluded holiday. October 13 itself can fall on the second Monday in October, which OPM lists as a federal holiday. A federal calendar does not establish a hospital's working schedule.
What changes when October 13 is a Friday?
Only 2 October 13 dates were Fridays in the SSA window: 2000, 2006. Their births were -7.2% relative to nearby Fridays. The other weekdays together had a difference of -3.8% against their own matched weekdays.
| Calendar group | Years | Occurrences | Births per occurrence | Control mean | Difference |
|---|---|---|---|---|---|
| Friday the 13th | 2000, 2006 | 2 | 12,175.5 | 13,122.6 | -7.2% |
| Actual federal Columbus Day | 2003, 2008, 2014 | 3 | 11,437.3 | 12,227.9 | -6.5% |
| Neither Friday the 13th nor federal Columbus Day | 2001, 2002, 2004, 2005, 2007, 2009, 2010, 2011, 2012, 2013 | 10 | 10,364.7 | 10,668.6 | -2.8% |
| Other weekdays | 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 | 13 | 10,612.2 | 11,028.4 | -3.8% |
The Friday group contains only two events. Comparing their raw birth average with all other October 13 dates would also mix different weekdays. Neither comparison identifies superstition or a scheduling decision. October 13 can itself be the federal October holiday when it falls on the second Monday; the calendar groups keep that overlap visible. The "Other weekdays" row contains both the Columbus Day dates and the dates in the "Neither" row. Those rows overlap and must not be added together.
For the broader question, our Friday-the-13th study counts all actual Friday-the-13th dates across the year. This page keeps its focus on one fixed birthday.
Sources and how to read the result
The ranking and birth share use FiveThirtyEight's preserved U.S. daily birth files: CDC/NCHS 1994 through 1999 and SSA 2000 through 2014, without overlapping years. The sources have different administrative coverage. Annual comparisons use only SSA, with each year's eligible control dates averaged before the pooled ratio is calculated.
The downloadable date analysis includes the exact control dates, exclusions and sensitivity windows. Read the methodology for rank definitions and source limits, or check October 13 against another birthday.