Warming Planting Zones

Climate Central analyzed 243 U.S. locations and found that 67% have already shifted to warmer planting zones between 1951-1980 and 1995-2024. Projections based on the SSP2-4.5 pathway suggest 90% of these locations will shift to warmer zones by mid-century (2036-2065), with the Upper Midwest expected to see the most significant warming.

• Between the 30-year periods of 1951-1980 and 1995-2024, 97% (235 of 243) of analyzed U.S. locations saw an increase in average coldest temperatures, with an average increase of 3.7°F. This resulted in 67% (164) of locations shifting to warmer plant hardiness zones.
• Historically, the most significant warming of coldest annual temperatures occurred in Alaska (+7.8°F), the Northwest (+4.7°F), and the Southwest (+4.3°F). Specific examples of large zone shifts include Reno, Nevada (6b to 7b) and Anchorage, Alaska (4b to 5b).
• Projections for the mid-century period (2036-2065), assuming the SSP2-4.5 pollution pathway, indicate that 100% of the 243 analyzed locations will experience warming of average coldest temperatures, with an average increase of 5.6°F. Consequently, 90% (218) of locations are projected to shift to warmer planting zones.
• The Upper Midwest is projected to be the most affected region by mid-century, with an expected increase in coldest temperatures of +7.8°F. Other highly affected regions include Alaska (+7.4°F), the Northern Rockies and Plains (+7.0°F), and the Northeast and Ohio Valley (+6.7°F).
• Shifting planting zones may expand the range of high-value crops like oranges, kiwis, and almonds, but they also facilitate the spread of invasive species and pests. Specifically, the invasive vine kudzu is projected to expand into the Midwest, Northeast, and Mid-Atlantic, while the brown marmorated stink bug's range is expected to grow due to warmer, wetter winters.

APA

Climate Central (2025). Warming Planting Zones. https://www.climatecentral.org/climate-matters/warming-planting-zones-2025

Chicago

Climate Central. Warming Planting Zones. 2025. https://www.climatecentral.org/climate-matters/warming-planting-zones-2025.

Wikipedia

{{cite report |author=Climate Central |title=Warming Planting Zones |date=30 April 2025 |url=https://www.climatecentral.org/climate-matters/warming-planting-zones-2025 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025warming, author = {{Climate Central}}, title = {{Warming Planting Zones}}, institution = {Climate Central}, year = {2025}, month = apr, url = {https://www.climatecentral.org/climate-matters/warming-planting-zones-2025}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }