Calculate Your Last Frost Date

In the northern U.S. and Canada, suburban hobby farmers and backyard vegetable gardeners calculate when to plant spring gardens based on something called the last frost date. This date is when gardeners can expect that killing frost won’t harm their immature plants.

For example, a certain variety of lettuce may suggest that you plant two weeks before the last frost date, while watermelon may require a planting date two weeks after the last frost date.

But when is the last frost date for your specific location?

This webpage uses historical information from the National Oceanic and Atmospheric Administration (NOAA) to predict the last frost date for your specific area. It also takes into account how much risk you are willing to take that there might be a deviation from past history.

The end result is a date that gives you the earliest start based on how much risk you are willing to take.

To get started, click the Start Here button below. Then select the appropriate radio buttons.

If you already know your last frost date and want to calculate planting dates for each of your vegetable plants, use the Suburban Hobby Farmer Planting Date Calculator.

Pick the weather station with weather most like yours

Frost risk versus earlier planting date

Determine how much risk of frost you are willing to take: