Sylvia Sky is a widely published author of books and articles about spiritual matters.
What Is the Most Common Astrological Sign?
From the available evidence, we can determine that the most common zodiac sun signs for adults older than 30 are Virgo, which governs those born around August 20th until about September 21st, and Libra, which governs those born in the last week of September and the first three weeks of October.
A popular meme ranks Scorpio first, then Virgo, then Gemini, then Pisces, but it provides no sources for that information. The under-30 U.S. population does seem to include a larger percentage of Scorpios, however. During the last 30 years, the February holidays of Valentine's Day, Mardi Gras (which takes place in February about 80 percent of the time), and the NFL's Super Bowl game day have all grown into major U.S. party occasions. As a result, the last 30 or so years seem to have seen more February conceptions and subsequent November births, with the most common being the 1st, 7th, 19th, 20th, and 21st.
For a true count, births from the 19th to 23rd of any month (which fall on the sun-sign "cusps"), must be counted year-by-year to pinpoint the placement of the sun as it leaves one zodiac sign and travels into the next.
What Is the Rarest Sun Sign?
The month with the fewest birthdays is February because it's the shortest month, but the full-length month with the fewest birthdays is January, making Aquarius (late January to late February) the least-common zodiac sign. Sources do not agree on the second-least-common zodiac sign, but some suggest it is Gemini, and others suggest Leo. If we were to count only the youngest Americans, the second-least-common zodiac sign would be Capricorn.
What Is the Most Common Birthday?
On average, 11,000 babies are born in the U.S. every day. When a Harvard University study counted U.S. births each day of each year between 1973 and 1999, it found the most common birthday for U.S. residents was September 16th, followed by September 9th, 23rd, 17th, 22nd, and 21st. Between 2000 and 2014, the Social Security Administration listed the most common birthday as September 9th, 19th, 12th, 17th, and 10th, followed by a surprise—July 7th.
What Is the Most Common Birth Month?
July was a trend, and in 2014 and 2015, it became the number-one U.S. birth month. August was a close second for both years and was followed by September. In 2013, the top three months were August, July, and October, respectively. From 2015 to 2017, the U.K.'s top three birth months were July, September, and August, respectively. These statistics are the latest available from the United Nations, which compiles birth-month data for every member country.
What Is the Least Common Birth Month?
The least common U.S. birth month is February. Social Security figures show that for the entire span of January 1st through May 22nd, the most popular birthdate is February 14th, or Valentine's Day.
What Are the Rarest Birthdays?
Studies of the most common individual U.S. birth dates show that they always cluster from midsummer to early autumn with minor variations. One study by the now-defunct data site anybirthday.com found the most common birthday to be October 5th and the least common to be May 22nd.
A Harvard study found December 25th, Christmas, to be the least common birthday, followed by January 1st (New Year's Day) and December 24th (Christmas Eve). This reflected a trend during the study years (1973–1999) of parents choosing to induce or delay childbirth out of convenience so it wouldn't conflict with special occasions.
Newer information from 2000–2014 shows that this pattern—fewer births on holidays—is unchanged, with the 10 least-common U.S. birthdays all falling on or adjacent to major holidays. December 25th is still the rarest birthday, with only about 6500 babies born that day. The next-least-common birthdays are January 1st, December 24th, July 4th, January 2nd, December 26th, November 27th, November 23rd, November 25th, and October 31st.
The rarest U.S. birthdays outside of holidays are April 1st and April 13th. An infographic analysis of Social Security data shows that when U.S. parents can schedule a birth, they tend avoid the 13th of any month, possibly due to superstition.
Does Birthday Prevalence Vary Based on Latitude and Hemisphere?
A study of births in Massachusetts covering 2005 to 2014 found that the most common birthday in that state was, surprisingly, June 27th, followed by September 19th, August 1st, then July 7th. Its much larger source study, originating at Princeton University, compiled 78 years of birth data including all 50 states and 118 mostly Northern-Hemisphere countries. Midsummer to autumn was baby season, but results showed that the farther north the birthplace, the earlier in the summer the most common birthdays. This could explain June 27th being the most common in Massachusetts. In equatorial countries, birth numbers are higher in mid-spring and late autumn.
In England and Wales, the least common birthdays are December 25th, December 26th (Boxing Day), and January 1st, and the most common is September 26th. The prevalence of late-summer-early autumn births is natural and—according to some sources—tied into the harvest season, during which food is especially plentiful.
In New Zealand, government birth data gathered from 1980 to 2015 shows December 25th is the least common birthday there as well, with the most common being September 30th. Christmas occurs in the summertime in New Zealand, so December, January, and February don't have to be cold to inspire more baby-making.
How Likely Are Your to Have the Same Birthday as Someone Else in the Room?
In a group of 70 random people, there is a 99.9 percent chance that two of them share a birthday. Among 200 people, the chance is 100 percent. Among only 23 people, the chance is still an amazing 50 percent.
How this can be so when there are 365 different birthdays? (February 29th is excluded.) This is a brain teaser for probability theorists, who call this "The Birthday Paradox" or "The Birthday Problem."
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2011 Sylvia Sky
NeptuneCastle on September 13, 2020:
You commented so many years ago but I find it interesting that you know so many people with birthdays on March 8th! I was born on that day too and know 4 people with the same birthday as me!
Sylvia Sky (author) from USA on December 09, 2019:
That is true!
Adrian Barrett on December 04, 2019:
I was born may 18 and my zodiac sign is taurus
DecembegirlSagitje16 on October 31, 2019:
Honestly, I think Cancer's, Leo's and Gemini's are really common in the UK. There are so many people born on end May, whole of June & July. I have NEVER ever met a Sagittarius other than myself. I feel like the rarest month is December/January because Capricorns and Sagittarius are uncommon
LunaticEight from 8th House on October 10, 2019:
This is such an interesting article and thank you for the time you took to research and write it. It seems to me that we all gravitate to the signs that we’re most compatible with, obviously, but in some cases it’s like the universe conspires to bring people into our lives who can help us evolve. I am absolutely inundated with Scorpio sun people in my family and amongst my in-laws. The love of my life for almost 19 years is also a Scorpio. So I would definitely pick that sign as the most prevalent. I’d totally agree with that Aquarius is likely the least common. I almost never bump into that sign.
Jean Bakula from New Jersey on March 21, 2019:
It seems like a huge proportion of my clients are Scorpios. Both my Mom and I were born on July 4th
coreythedino on February 11, 2019:
I'm born on april 1st so im an aries
Stella Ofogba on December 27, 2018:
I choose Scorpio has most common and it turns out to be correct. My birthday is October towards the end dough but I have ways come across people born into October including my dates.
Lisa Hollen on October 14, 2018:
From my experience the most common to least common signs i know are (1 being most common and 12 least, and im a scorpio):
leannh11 on April 23, 2018:
My birthday is the 13th of June so I guess that's something special about me.. Well, I wasn't born on friday luckily. It was a monday. I am a gemini. I have known a lot of people with similar birthdays or on the 13th a month apart though.. a lot even shared the same day as me.
Jinie on November 14, 2016:
My sister's birthday is on December 25th, the least common birthday!
Sylvia Sky (author) from USA on September 16, 2015:
Hi, Jo, and happy birthday! For free you can input your birth information at the website alabe.com and you will receive a printable chart and a very basic but genuine reading of the features of your birth chart. If you want to learn more about the present or future, consult a professional astrologer.
Jo Jo Davidson on September 15, 2015:
I was born September 16, 1949 at 11:43 Am. How can I get an accurate reading? Where do I go to find it? Thank you Jo Jo Davidson
Jonathan Shearman on July 05, 2013:
The most common zodiac signs are Libra and Scorpio, most people acoount for sag, cap, aqu, and pisceans. Libra is the most common zodiac sign found among social crowds and bystander people, you can walk up to most strangers and ask them their birthdate, and you will get from 4 of 5 people who say scorpio or a malevolent left sided sign, a Libran birthday, to get an Aries would have to be a little more intelligently or ingenuatively pinpointed, they are a more randomized social zodiac sign among births.
The rarest zodiac signs confirmed are Gemini and Leo.
Leos are found very scarcely among databases of people revolving around subjects or personell, and they all sway in secondary thinking, antiheroism, arrogance, popularity, or personal safety are some examples, studies by astrology analysts, scientists, have shown Gemini to be the other rare sign, they are usually scarce among extremely popular celebrities of mainstream entertainment and music arts.
Sylvia Sky (author) from USA on April 24, 2013:
The Sun enters each sign at a slightly different time each year. These are the dates the Sun entered (or will enter) Libra:
2009: Sept. 22
2010: Sept. 24
2011: Sept. 23
2012: Sept. 22
2013: Sept. 22
Plouymarks on April 24, 2013:
I know 6 people born on March 8th and in the month of March as a whole. That's so weird! Also Libra's astrological sign doesn't start until the 23rd of September to October 22nd.https://exemplore.com/astrology/The-Most-Common-an...
Guest on November 29, 2012:
For me, the most common to least common ranking for the signs goes like this (1 being most common, 12 least common):
(Taurus and Libra IMO are pretty tied though -- I don't see very many of either.)
Also, the least common birthday is definitely February 29th... Don't even need to question it.
lovedoctor926 on October 25, 2012:
Sept 26- so that makes me libra. Voted up interesting hub.
Fotinoula Gypsyy from NYC BABY on October 25, 2012:
Funny pretty much all of my family is Aquarius, while me and my cousin are both considered outsiders because we are Libras. Interesting hub to read!
magnorth on July 04, 2012:
i know lots of people born in february and 2 people born on 22 may. although almost everyone in my life is a scorpio or libra. i know of 5 people with my birthday july 5 and 13 people around my birthday!
Tatiana on June 15, 2012:
My question has always been "WHY are there more/less birthdays at one time of a year than another?" My mom is an obstetrician so I definitely notice when some months are busier for her in the delivery room than others! All I can think of for the September business (ironically, my dad's birthday is in August and my mom's is in September) is that couples may be 'busy' around the Christmas/New Year holidays. Wonder why February is infrequent though!
Baby Ferlyn from Singapore on June 03, 2012:
My ascendant is in Scorpio too. My moon is in Libra. =]
Sylvia, do you know where can i read/learn about:
"How does our Sun/Moon/Rising combination affect us?"
Sylvia Sky (author) from USA on June 03, 2012:
My ascendant is Scorpio. My moon is Scorpio also.
Ferlyn on June 03, 2012:
I've never met another January 23 in my life.
And hey, you're the 1st one!! ='3
May i ask wads your ascendant sign?
Sammie on June 02, 2012:
Mine Is January 22nd.So close DL
Sylvia Sky (author) from USA on June 01, 2012:
That is interesting; I have never met another January 23 either!
Debbie Andrews on June 01, 2012:
I agree that Feb 7th (& all Aquarian birthdays) are the least common..I have never met anyone born on my birthday (7th Feb). Alas, if only there WERE more Aquarians in the world - it might be a better place because we care so much for the good of humanity.. :D
That sounds a bit big-headed but not meant to be..
Ugo on May 21, 2012:
WOW! MY BIRTHDAY IS JULY 9, 2002. BUT I CANT BEILEVE OCTOBER AND JULY ARE IN NECK-NECK
INFECT the mother, PULL the switch on May 08, 2012:
I though saggitarius was the least common sign.
For birthday.. I'd have to agree around feb.
then again i bet all the signs and birthdays are evene'd out.
most common sign to me, is Capricorn.
Astrologist on April 19, 2012:
i Think feb 7 least common brithday date.......
j9dscfisjhdidro on April 14, 2012:
Who CARES what your sun or star sign is?
Estellsa on March 03, 2012:
Wow, my birthday is on May 22nd, and I know someone who was born on the same day in the same hospital! I had no idea it was one of the least common birthdays, I would have never guessed!
Sylvia Sky (author) from USA on January 27, 2012:
I agree Pisces gets the short end of the stick, the most neglected and poorly understood of all Sun signs. Probably because it is the most complex.
Barn Lars on January 27, 2012:
I've been looking through a few articles on 'least common' and 'most common' astrological signs...and not ONE mentions Pisces.
'Most ignored astrological sign'? Sniffle. End of February, for me.
Gem Scooper on August 14, 2011:
Hi Sylvia--Never have I paid attention to who has the most common birthdays all throughout the year, but when I read your article, then- oh! It must be the season why births happen around September...and to think that the least date of birthday celebrants is May 22nd is somewhat an irony on my end...I am a Gemini, and my fellow Geminians in my work-group were born on 5/22nd...and they know each other- though they were born 16 years apart, and from 2 continents. Very informative!
Jean Bakula on July 09, 2011:
I've come back to this hub again! My son has attended a martial arts school for 13 years. I can't tell the percentage, but out of the main 25 higher ranks, at least 12 of them are Scorpios! He is included, having a Scorpio sun and moon. Thankfully he has Virgo rising, and a stellium in Sag, so he's downright sunny for a double Scorp! Take care, Jean
Jen on July 08, 2011:
Wow September 16th is the most common birthday. That's my birthday
Sylvia Sky (author) from USA on June 09, 2011:
Thank you for the compliment! Birth times are hard to get. If only people knew how astrologers need those! People aren't looking at the clock while a baby is being born. Mothers' memories aren't always reliable. There is daylight savings time which can differ from state to state and, for WWII-era births, War Time to contend with and correct for. And I am not convinced that astrological "rectification" of birth times gives accurate results.
Jean Bakula from New Jersey on June 09, 2011:
I have gone nuts trying to get birth certificates for people in my parent's generation. It used to be easier before 9/11, at least in NJ. All I had to do was write to the Clerk of Whatever Township the hospital was in. It's so frustrating. I have good guesses about some of their ascendants, but verification would be nice. My Mom was born on July 4th, and so was I. She says her Dad always spoke of the fireworks going off. But when I got her Cert, she was born around dawn that morn, an odd time for fireworks. Interesting B-day info though, I thought people were probably mostly born earlier in the summer! Nice hub!