United States Map 1916 Last Killing Frost Print - Gulf Coast, Great Plains, Rocky Mountains

William Gardner Reed compiled this Average Dates of Last Killing Frost in Spring map for the U.S. Department of Agriculture's Atlas of American Agriculture, printed in Washington as part of a federal reference on the country's land, climate, soils, and vegetation prepared under O.E. Baker of the Bureau of Agricultural Economics. Drawn in 1916 and finished in full color, the sheet uses blue and red shading to mark, region by region, the average calendar date after which frost was no longer expected to threaten spring planting, and carries a smaller inset showing the actual last frost dates recorded in the specific year 1914. A data table in the corner tracks year-to-year departures from the average at five weather stations, giving farmers and agronomists a sense of just how unreliable any single year's frost date could be.

The Gulf Coast and Florida appear in the earliest color band, their last frost typically falling in January or February, while the northern tier of states and the Rocky Mountain high country carry the latest shading, with frost sometimes lingering into June. The Great Plains and Midwest fall in between, their mid-spring frost dates governing the planting calendar for the corn and wheat belts. The 1914 inset lets a viewer compare that particular year's actual frost pattern directly against the long-run average shown on the main map. Together the color bands, the inset, and the station data describe frost not as a fixed calendar date but as a genuinely variable risk farmers had to plan around every year.

How farmers once planned their planting calendar before modern forecasting is the specific appeal of this sheet, a fitting gift for a gardener or grower curious about their own region's frost history and a natural fit for a collector of American agricultural science. The store also carries six companion sheets from the same Atlas of American Agriculture, covering great soil groups, parent materials of soils, natural vegetation, physical features, average annual precipitation, and summer temperatures; this sheet is the only one in that set focused specifically on the timing of spring frost. It's printed unframed and available in a range of sizes to fit whatever wall it's headed for.