birthday odds .

Rarest and most common October birthdays: all 31 dates ranked

October 31 was the rarest October birthday by total births in U.S. records from 1994 through 2014. Compare all 31 dates by count and rank.

Reviewed

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. They show 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 recorded births than October 1 (210,629 versus 247,196).

Open October 31 in the birthday checker
Birth counts for each October dateCalendar order, with a zero baseline. A triangle marks October 31. A circle marks October 1. Exact counts and ranks appear in the table below.0125,000250,000October 1: 247,196births1October 2: 244,271birthsOctober 3: 246,263birthsOctober 4: 242,165birthsOctober 5: 237,559births5October 6: 238,783birthsOctober 7: 238,644birthsOctober 8: 238,416birthsOctober 9: 234,977birthsOctober 10: 243,883births10October 11: 237,531birthsOctober 12: 232,009birthsOctober 13: 226,792birthsOctober 14: 234,977birthsOctober 15: 237,459births15October 16: 234,508birthsOctober 17: 238,374birthsOctober 18: 235,107birthsOctober 19: 228,654birthsOctober 20: 233,282births20October 21: 233,044birthsOctober 22: 235,268birthsOctober 23: 233,099birthsOctober 24: 237,881birthsOctober 25: 235,823births25October 26: 230,333birthsOctober 27: 232,423birthsOctober 28: 233,982birthsOctober 29: 232,185birthsOctober 30: 228,305births30October 31: 210,629births31
Recorded births by day of October, 1994–2014. The axis starts at zero so small differences stay small. Triangle (red): October 31. Circle (dark ink): October 1. Scroll sideways on smaller screens.

All 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.

October dates by total recorded U.S. births, 1994–2014. Share uses all 85,712,738 recorded births.
DateMonth rankOverall rankBirthsShare of all births
October 1#1#47247,1960.288%
October 2#3#72244,2710.285%
October 3#2#53246,2630.287%
October 4#5#94242,1650.283%
October 5#11#129237,5590.277%
October 6#6#115238,7830.279%
October 7#7#118238,6440.278%
October 8#8#120238,4160.278%
October 9#17#168234,9770.274%
October 10#4#79243,8830.285%
October 11#12#130237,5310.277%
October 12#26#217232,0090.271%
October 13#30#317226,7920.265%
October 14#17#168234,9770.274%
October 15#13#131237,4590.277%
October 16#19#175234,5080.274%
October 17#9#122238,3740.278%
October 18#16#164235,1070.274%
October 19#28#294228,6540.267%
October 20#21#193233,2820.272%
October 21#23#199233,0440.272%
October 22#15#159235,2680.274%
October 23#22#198233,0990.272%
October 24#10#127237,8810.278%
October 25#14#152235,8230.275%
October 26#27#250230,3330.269%
October 27#24#206232,4230.271%
October 28#20#183233,9820.273%
October 29#25#211232,1850.271%
October 30#29#299228,3050.266%
October 31#31#356210,6290.246%

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.

For each year from 1994 through 2014, we compared Halloween with October 17 and 24 of that year. All three dates share a weekday. The two comparison dates averaged 11,339.4 births per date. Halloween averaged 11.5% fewer births.

Using October 24 and November 7, one week on either side, gives a similar gap of 11.6%.

The Halloween birthday study uses SSA records from 2000 through 2014 and four nearby comparison dates per year. It shows each annual result. Its comparison period and dates differ from those used here.

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.