birthday traffic

How common are May birthdays?

Published by Birthday Traffic · · Sources and method

May is the 6th most common birth month of the 12, at 11,022 recorded births per day, 1.4% below an average day across 85,712,738 U.S. births from 1994–2014. Its most common date is May 23 (#89 of 366) and its quietest date that occurs every year is May 26 (#349).

Every date is coloured by the same six rarity tiers the reveal uses; the small number is its rank of 366 from most common.

Every May date: recorded U.S. births 1994–2014

One column per May date in calendar order, coloured by rarity tier, total recorded births 1994–2014.

Every May date: recorded U.S. births 1994–2014One column per May date in calendar order, coloured by rarity tier, total recorded births 1994–2014.050,000100,000150,000200,000250,0001: 231,96912: 234,3643: 229,8324: 225,6745: 233,27056: 230,6787: 230,6378: 231,0469: 232,748910: 233,30111: 226,25712: 231,98113: 225,3161314: 233,28715: 235,25816: 237,93317: 234,4181718: 229,51819: 231,66420: 235,84621: 237,2492122: 237,93223: 243,051243,05124: 239,49025: 228,0902526: 218,924218,92427: 225,13028: 227,50129: 227,2872930: 229,81031: 225,906
Calendar order; each column is the date’s total across the window, in its rarity colour.

Every May date, ranked

Ranked by total recorded births across the 21 years, the same measure as the site-wide rank of 366.

Recorded U.S. births per May date, 1994–2014
DateTotal birthsRank of 366Odds
May 23243,051#891 in 353
May 24239,490#1091 in 358
May 16237,933#1251 in 360
May 22237,932#1261 in 360
May 21237,249#1331 in 361
May 20235,846#1511 in 363
May 15235,258#1601 in 364
May 17234,418#1781 in 366
May 2234,364#1811 in 366
May 10233,301#1911 in 367
May 14233,287#1921 in 367
May 5233,270#1941 in 367
May 9232,748#2031 in 368
May 12231,981#2191 in 369
May 1231,969#2201 in 370
May 19231,664#2251 in 370
May 8231,046#2361 in 371
May 6230,678#2431 in 372
May 7230,637#2441 in 372
May 3229,832#2621 in 373
May 30229,810#2661 in 373
May 18229,518#2761 in 373
May 25228,090#3041 in 376
May 28227,501#3101 in 377
May 29227,287#3121 in 377
May 11226,257#3211 in 379
May 31225,906#3261 in 379
May 4225,674#3281 in 380
May 13225,316#3311 in 380
May 27225,130#3331 in 381
May 26218,924#3491 in 392

May in the year

May has 8.37% of all recorded births in this sample, over 651 observed days. Months are ranked by births per day. On that measure May is #6 of 12, against September at the top (11,811 per day) and January at the bottom (10,721). Full month ranking.

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Sources, method and limits

Main ranking: 85,712,738 recorded U.S. births on 7,670 calendar dates, 1994–2014. CDC/NCHS daily counts for 1994–1999 and Social Security Administration daily counts for 2000–2014, as compiled by FiveThirtyEight and attributed under CC BY 4.0. The overlapping years 2000–2003 are counted once.

Ranks compare totals across the 366 observed month-and-day dates. February 29 occurred 5 times in this window; every other date occurred 21 times, so per-occurrence figures are used wherever seasonality is compared.

Every figure above comes from the administrative records named here, at the granularity those records publish: a day, a month or a year. Coverage and definitions differ between countries and eras, so two sources are combined only where their documentation states the windows are separate, and the page where that happens says so.

Full method, leap-day treatment and definitions.

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