Baby Names by Month of Birth: What the ONS Data Shows

The number one girls' name in each month, 2025

Almost every baby name list treats a year as a single block. The Office for National Statistics does not. Table 5 of its England and Wales datasets gives a separate top 10 for each month of birth, and the twelve lists are not identical. These are counts of registered births, not survey estimates, and they were released on 9 July 2026 covering babies born during 2025.

What the twelve lists actually show

The boys' list does not move at all

Muhammad was the most popular boys' name in every single month of 2025, and Noah was second in every single month. There is no seasonal story on the boys' side of the data at all. Any article offering you "boys' names for a summer baby" based on popularity is not reading the registry. The only movement is at third place, where Arthur took the slot in March, November and December, and Luca took it in April, June, July, September and October.

Four different girls' names reached number one

Olivia led eight months of the year. Isla took July, Lily took August, Amelia took September and Florence took December. Florence is the striking one: she is fifth for the year as a whole with 1,924 babies, but in December she beat Olivia outright. Poppy behaves similarly, reaching second place in November having finished seventh for the year.

The size of the effect is small

This is the part that seasonal name lists leave out. Olivia's monthly counts run from 175 in July to 219 in May — a spread of about a quarter. December's winning count of 182 for Florence is lower than Olivia's total in ten of the twelve months. Monthly totals differ too: 26,605 boys were born in July against 22,884 in February, so a name can gain or lose a rank simply because more babies were born that month. Treat month-level rankings as a curiosity rather than a trend.

Some names really are seasonal, but they sit below the top 10

The ONS reported this directly in its 2023 bulletin, noting that Holly, Robyn and Joseph were more popular in December, while Summer and Autumn were more popular in their respective seasons. Those names never appear in a monthly top 10, so the monthly tables cannot show the effect — but the annual full lists show they are in real use. Holly was given to 285 girls in 2025, Summer to 429, Autumn to 434, Robyn to 611 and Noel to 65 boys.

Names whose meanings point at a season

Two corrections worth making. Neve is not the Italian word for snow used as a name; Behind the Name records it as an Anglicised form of the Irish Niamh, which means "bright". And Yuki is not simply "snow" in Japanese: the reading can be written with kanji meaning "happiness" or with kanji meaning "snow", and only the written form settles it.

Why the December effect is the strongest one in the table

December is the only month where a name outside the annual top four takes first place on the girls' side, and it is also the month with the clearest cultural anchor. Christmas names are the one category where the calendar has a name attached to it that parents already know: Holly, Ivy, Noel, Noelle, Natalie and Natalia all carry a December association, and Ivy in particular is a genuinely major name, ninth for the year with 1,698 babies. Florence carries no Christmas association at all, which is a reminder that a monthly winner can be a statistical accident rather than a seasonal choice. With 182 babies separating first from second by a single name, December's top spot rests on a margin of one baby.

The tables cannot tell you when a name was chosen

A birth is registered after it happens, and a name is usually chosen before. The month of birth is the only date in this table, so a December baby named Holly may have been called Holly for months before December arrived, and a July baby named Summer may have been named in January. The ONS records outcomes, not decisions. That limits the seasonal reading of these tables far more than the small monthly swings do, and it is why the 2023 bulletin describes the pattern rather than claiming a cause for it.

How to use this

If you already have a due date, the monthly tables tell you roughly how common your shortlist will be among the babies born alongside yours — which is the number that actually matters in a school year group. But a due date is an estimate, and roughly a third of the babies in any monthly column were not born in the month their parents were expecting.

If you want a name that nods at the season, choose it for the meaning rather than the ranking. The seasonal names in the table above are all uncommon enough that none of them will define a classroom, and every one has a meaning you can point to in a dictionary rather than a name blog.