This tool is an interactive map that provides county-level estimates of historic (1981–2019) annual dates of last frost, as well as dates of first 70°F and first 80°F maximum temperatures.
Future Projected Changes in Date of Last Freeze and Date of First Warm Day
This tool is excerpted from Chesapeake Bay Watershed Climate Impacts Summary and Outlook for Spring 2020.
- Future projections show that the region as a whole might experience the onset of warm spring temperatures 15–26 days earlier than normal by the end of the century, and the last day of frost 12–20 days earlier.
- Under both future-emissions scenarios, the southern portion of the Mid-Atlantic is projected to continue experiencing the date of last freeze earlier than the northern half of the region.
- Future projections indicate that the region could experience an increase in the number of counties with dates of last freeze in February and a decrease in the number of counties with dates of last freeze in May and June. This trend toward earlier dates of last freeze is stronger in the southern half of the region.
- In both high and low future-emissions scenarios, the majority of the southern half of the region might experience the date of the first 70°F day in January and the date of first 80°F day by March by the end of the century.
More information on RCP 4.5 can be found in Allison M. Thomson, Katherine V. Calvin, Steven J. Smith, G. Page Kyle, April Volke, Pralit Patel, Sabrina Delgado-Arias, Ben Bond-Lamberty, Marshall A. Wise, Leon E. Clarke, and James A. Edmonds, “RCP4.5: A Pathway for Stabilization of Radiative Forcing by 2100,” Climatic Change, Vol. 109, 2011, pp. 77–94. As of June 8, 2020: https://doi.org/10.1007/s10584-011-0151-4Return to text ⤴
More information on RCP 8.5 can be found in Keywan Riahi, Shilpa Rao, Volker Krey, Cheolhung Cho, Vadim Chirkov, Guenther Fischer, Georg Kindermann, Nebojsa Nakicenovic, and Peter Rafaj, “RCP 8.5—A Scenario of Comparatively High Greenhouse Gas Emissions,” Climatic Change, Vol. 109, 2011, pp. 33–57. As of June 8, 2020: https://doi.org/10.1007/s10584-011-0149-y Return to text ⤴
More information on RCP 4.5 can be found in Thomson et al., 2011. Return to text ⤴
More information on RCP 8.5 can be found in: Riahi et al., 2011. Return to text ⤴