These are the 4 seasons at my house: Winter, Spring, Summer, FOOTBALL!!

Sizes and Circumference Measurments:
NewBorn~ 13 inch
0-6 Months~ 14.5 inch
6-12 Months~ 16 inch
1-2 Years~ 17.5 inch
2-5 Years~ 19 inch
5 Years- Adult small~ 21 inch

To knit this quick and cute hat knitters must know how to:

knit in the round on circular and double pointed needles
purl
decrease by knitting 2 together (k2tog)