Which April birthday is rarest? All 30 dates ranked

April 1 was the rarest April birthday and April 4 was the most common in these U.S. birth records from 1994 through 2014. The comparison above includes every April date, with its rank within the month and among all 366 birthday dates.

What is the rarest birthday in April?

April 1 had 217,042 recorded births across the period. Its overall commonness rank is 352 out of 366, where #1 means most common. It accounts for 0.253% of all births in the dataset, not just April births.

April 13 had the second-lowest total in the month. Select either date above to compare it with your birthday, or see the full rarest-birthday ranking for the rest of the year.

What is the most common birthday in April?

April 4 leads April with 236,536 births. It ranks 143 across the full year, so even April's most common date falls outside the overall top 100.

April 4 had 9.0% more births than April 1 across the period. That difference is easier to see in the birth counts than in the ranks alone. You can compare any two April dates above.

Does April Fool's Day explain April 1's ranking?

These records show that April 1 had fewer births than every other April date. They do not tell us whether parents avoided the date, how deliveries were scheduled, or what caused the difference.

Births also differ by weekday. Each date falls on a changing mix of weekdays over the years, and the April ranking does not adjust for that mix. A low total alone cannot establish an April Fool's Day effect.

How to read the April rankings

Both ranks measure commonness: #1 is the highest birth total. The April rank compares 30 dates; the overall rank compares 366. Sorting the table from rarest to most common changes the row order, not the meaning of the ranks.

Every April date occurred equally often in this period, so sorting by total births gives the same order as sorting by births per occurrence. The birth-share column divides each date's births by all recorded births across all months. It is not an estimate of the share of people alive today who have that birthday.

If you want to compare April with other months, use the birth-month guide. For a date outside April, use the birthday checker.

Sources and limitations

We calculate these results from daily U.S. birth records compiled by FiveThirtyEight, using CDC/NCHS for 1994 through 1999 and SSA for 2000 through 2014. We exclude the overlapping CDC years to avoid double counting.

The sources have different administrative coverage. This is a historical U.S. comparison, not a worldwide or current-year ranking. The methodology explains source selection, birth shares, and how ties are ranked.