Someone polled thousands of people and asked which month is the BEST month to have a birthday. June was the #1 answer with 18% of the vote, and July is a close second at 16%. Warmer months did better in general.
May is the third-best month for birthdays with 9% . . . then August, 8% . . . and April, September, and October with 5% each. Five months tied for last with just 3% of the vote: November, December, January, February, and March.