Old Farmer's Almanac Frost Dates

The Old Farmer's Almanac's frost predictions are based on a formula created by founder Robert B. Thomas in 1792. He compared solar patterns with average temperatures, establishing a closely guarded formula that the Almanac still uses today. These dates are predictions of the last light freeze, defined as 28°F (-2°C), which can damage sensitive plants. Gardeners use these dates to gauge when it's safe to plant without risking frost damage. Keep in mind that the dates are regional predictions, and microclimates in your yard can vary. Factors like elevation, sun exposure, and proximity to bodies of water influence local frost dates.