October 31 is the rarest October birthday in these historical U.S. records, with 210,629 births. October 1 is the most common, with 247,196. The chart and table cover all 31 dates from 1994 through 2014, with ranks within October and across the full year.
Compare October birthdays
October 31 had the fewest births and October 1 the most among October dates in these U.S. records. Choose two dates to see how far apart they are.
CDC/NCHS + SSA via FiveThirtyEight · 1994–2014 · 85,712,738 births
October 31
- Within October
- #31 of 31
- Across the whole year
- #356 of 366
- Recorded births
- 210,629
- Share of all births
- 0.246%
Both ranks count from most common (#1) to rarest. Ties share a rank.
October 31 had 14.8% fewer births than October 1 (210,629 versus 247,196).
Open October 31 in the birthday checkerAll 31 October birthdays ranked
Month rank compares only October dates. Overall rank compares all 366 dates, including February 29. #1 is most common in both columns.
| Date | Month rank | Overall rank | Births | Share of all births |
|---|---|---|---|---|
| October 1 | #1 | #47 | 247,196 | 0.288% |
| October 2 | #3 | #72 | 244,271 | 0.285% |
| October 3 | #2 | #53 | 246,263 | 0.287% |
| October 4 | #5 | #94 | 242,165 | 0.283% |
| October 5 | #11 | #129 | 237,559 | 0.277% |
| October 6 | #6 | #115 | 238,783 | 0.279% |
| October 7 | #7 | #118 | 238,644 | 0.278% |
| October 8 | #8 | #120 | 238,416 | 0.278% |
| October 9 | #17 | #168 | 234,977 | 0.274% |
| October 10 | #4 | #79 | 243,883 | 0.285% |
| October 11 | #12 | #130 | 237,531 | 0.277% |
| October 12 | #26 | #217 | 232,009 | 0.271% |
| October 13 | #30 | #317 | 226,792 | 0.265% |
| October 14 | #17 | #168 | 234,977 | 0.274% |
| October 15 | #13 | #131 | 237,459 | 0.277% |
| October 16 | #19 | #175 | 234,508 | 0.274% |
| October 17 | #9 | #122 | 238,374 | 0.278% |
| October 18 | #16 | #164 | 235,107 | 0.274% |
| October 19 | #28 | #294 | 228,654 | 0.267% |
| October 20 | #21 | #193 | 233,282 | 0.272% |
| October 21 | #23 | #199 | 233,044 | 0.272% |
| October 22 | #15 | #159 | 235,268 | 0.274% |
| October 23 | #22 | #198 | 233,099 | 0.272% |
| October 24 | #10 | #127 | 237,881 | 0.278% |
| October 25 | #14 | #152 | 235,823 | 0.275% |
| October 26 | #27 | #250 | 230,333 | 0.269% |
| October 27 | #24 | #206 | 232,423 | 0.271% |
| October 28 | #20 | #183 | 233,982 | 0.273% |
| October 29 | #25 | #211 | 232,185 | 0.271% |
| October 30 | #29 | #299 | 228,305 | 0.266% |
| October 31 | #31 | #356 | 210,629 | 0.246% |
Each October date occurs 21 times in this period, so ranking by births per occurrence gives the same order within this month.
How rare is a Halloween birthday?
October 31 ranks 356 out of all 366 dates, where rank 1 means most common. It averaged 10,030.0 births on its 21 occurrences in the records.
To account for the day of the week, we compared each Halloween with October 17 and 24 of the same year. Those dates fall exactly two weeks and one week earlier, so all three share a weekday. The two comparison dates averaged 11,339.4 births per date. Halloween averaged 11.5% fewer.
Using October 24 and November 7, one week on either side, gives a similar gap of 11.6%.
That gap is still an observation, not an explanation. The records do not show how many deliveries were scheduled or why any date had fewer births. The comparison also does not separate Halloween from other changes across October. Our weekday study shows why weekday context matters.
Is October 13 rare? What about October 11?
October 13 is the second-rarest October date, with 226,792 births. It ranks 30 within October and 317 across the year. October 11 is closer to the middle: rank 12 in October and 130 overall.
October 1 had 17.4% more births than October 31 over this period. Use the date comparison to see the count difference between any two October birthdays, rather than judging from ranks alone.
What do the two October ranks mean?
The October rank compares 31 dates; the overall rank compares 366. In both, rank 1 means the most births. Every October date occurred 21 times in this period, so births per occurrence would give the same order within the month. Birth share divides a date's count by all recorded births across all months, including births outside October.
For a whole-month comparison, see birth months. The rarest-birthday ranking covers the entire calendar, and the birthday checker works for any date.
Sources and limits
We use daily U.S. birth records compiled by FiveThirtyEight: CDC/NCHS for 1994 through 1999 and SSA for 2000 through 2014. We exclude overlapping CDC years. The two sources have different administrative coverage. These counts describe births recorded in those years, not everyone alive today or births worldwide. The methodology explains the source selection and ranks.
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