What I found was a nifty little site called Dave's Garden. Which has all kinds of gardening information including a look up by Zip Code of the First and last freeze/frost date. Here was my results:
Each winter, on average, your risk of frost is from November 14 through April 1.
Almost certainly, however, you will receive frost from December 2 through March 20.
You are almost guaranteed that you will not get frost from April 13 through October 29.
Your frost-free growing season is around 227 days.