birth_month avg_crawling_age temperature
January     29.84            66
February    30.52            73
March       29.70            72
April       31.84            63
May         28.58            52
June        31.44            39
July        33.64            33
August      32.82            30
September   33.83            33
October     33.35            37
November    33.38            48
December    32.32            57