Please note that the dates on this chart are approximate. Most years, the first and last frost will fall within two weeks of the date on the chart, but some years, we get a very early frost or a late snow storm that throws the dates off. Use your discretion (and your local weather forecast!) along with this chart to plan your seed starting and planting. First and Last Frost Dates, by Hardiness Zone USDA Hardiness Zone First Frost Date Last Frost Date 1 July 15th June 15th 2 Autust 15th May 15th 3 September 15th May 15th 4 September 15th May 15th 5 October 15th April 15th 6 October 15th April 15th 7 October 15th April 15th 8 November 15th March 15th 9 December 15th February 15th 10 December 15th January 31st 11 No frost. No frost.