Hardiness zone changes at weather stations
The current USDA Plant Hardiness Zone Map is based on average yearly minimum temperatures over 1976-2005 and therefore doesn't fully include recent warming. To illustrate this, this page shows the estimated change in average yearly minimum temperature and the corresponding hardiness zone since 1976-2005 at North American weather stations with almost complete daily temperature records in HCDN. For details on the method used, see this paper.
© 2013 Nir Krakauer; released under GPLv3. This calculator is intended for illustrative and educational purposes only, and is not warrented for any application.