As far as that goes, I’d be surprised if there aren’t some porn stars with months as part of their “bed names.” 
My first name is ‘August’ & so was my Paternal Grandfather.
Do any of you go by Gus?
Go to IMDB and plug the months into the search engine, with “Names” selected. You’ll get hits for every month as a first name. I don’t know how many are stage names but every month is represented.
Avril Lavigne counts, if you accept foreign names (“Avril” means April in French).
And since “Julio” means July in Spanich, Julio Iglesias may count.
In Lonesome Dove there was a character named “July Johnson”. Doesn’t fit the OP but makes it somewhat more likely that a person could have that name. Julie/Julia/Jules are possible variants.
My uncle and his father were both named August, which is what I was thinking of when I made the comment above. The famous Augusts didn’t occur to me until others mentioned them.
…and Augustus McCrae
Frederick March?
March, Frederick if we can’t think of somebody with that first name. March Hare would work if it/he/she were “real.”
Are we ignoring March Fong Eu then?
A friend of mine has a friend whose first name is July, but I’m not posting her whole name her, so it probably doesn’t count.
Sorry, I must have missed seeing Mr. Eu being mentioned.
Yeah, it’s probably good to keep the real names limited to public figures or people we would want to get in trouble. I guess convicted felons would work, though.
It’s at a tangent, but my mother once had a student named Sunday Monday. The girl hated the name.
That’s awful close to Mizzou. And I owe her a profound apology.
No shit!
My IRL last name is a month. It’s annoying as hell.
I don’t think we can use old census names, so February is still on the list. We’re down to four or five.
February
?July Are we accepting Julio?
September
November (I really wish we could include November Dick.)
December
There was an actor named July Jones - http://ia.media-imdb.com/images/M/MV5BMjAzNDE0MDExNl5BMl5BanBnXkFtZTcwNTU0OTgyMQ@@._V1_SX214_.jpg
There’s a talent agent named September Day (really) - http://www.imdb.com/name/nm2783295/?ref_=fn_nm_nm_3
There’s a director/writer named November Wanderin, though it’s not her birth name - November Wanderin - IMDb
July Jones - July Jones - IMDb
There are a dozen other actors with the first name July.
September Day
September Williams
September George Hill