September 16th is the day with the most births in Portugal. And with less?

Sand you meet a lot of people who celebrate their anniversary in September, so just know that it's not just a coincidence. In Portugal, the ninth month of the Gregorian calendar is the most births. Christmas season is last.

According to the tool Rare Birthday, which uses as the database of National Institute of Statistics (INE), referring to the years between 1980 and 2025, that is, almost 5 million births, in september there is a boom of birthdays.

The peak of peaks occurs mid-month: September 16th stands out as the date with the highest number of birth records in the country. However, every month is statistically the most fertile in births in the country.

The explanation for this phenomenon is not official; however, it may be in mathematics. Because, as human pregnancy usually lasts nine months, this means that the conceptions took place around Christmastime, perhaps during Christmas and New Year's festivities, when the days are colder and there is more time in the family.

In reverse, this is the time of year where there are fewer births in Portugal. Second Rare Birthday, days like December 24 and 25 and January 1 present marked breaks in the records, and Christmas Day, which coincidentally is the day when, for Catholics, Jesus was born, is the day during which fewer people are born in the country.

This decrease may be related to the fact that it is a holiday and that there is a reduction in the planned activity in maternity hospitals. Since induced births and scheduled cesarean sections are not scheduled for these days, this might explain why Santa brings fewer babies.

If you were curious about the days when more (and less) babies are born in Portugal and if your birthday is more or less ‘competitive’, the best thing is to see the chart below:

Birthday Calendar© Rare Birthday