CSF Grape Hardiness & Freeze Risk

© Cornell University, 2016. Credits: Tool Developed by Art DeGaetano & Rick Moore.

While climate change is causing frosts and freezes to be less severe, spring frosts and freezes are not receding as quickly as flowering is advancing, resulting in increased risk for damaging cold snaps. This tool, explained below, is designed to give you a graphical view of your freeze risk based on hardiness temperature, for a variety of grapes.

Please also take our brief survey to give us feedback on the Grape Hardiness tool.

How do I use this tool?
1. Select your location by inputting your county, state, zip code, or address after clicking on the “Change Location” field, or by navigating to your desired spot on the pop-up map, after clicking “save and select location”
2. Use the control panel on the left to input your date of interest, which will center the graph output on this date, with a window of 30 days surrounding it.
3. Use the control panel on the left to choose your grape variety – the graph will automatically update depending on your choice for every parameter.
4. Once all your information is chosen, view the graph output
5. Toggle between “Season to Date” and “Recent Trend” graphs

After you have set your crop variety and location, the graph on the right will automatically update with the hardiness level of corresponding to your specific variety, and the observed daily minimum temperature observed at your selected location. If the blue minimum temperature crosses into the red hardiness line, buds are at risk for freeze damage and you should take proper precautions. Expected hardiness and minimum temperatures are also shown into the future based on weather forecasts to help you anticipate potentially damaging periods.  Hovering over the graph on a particular day allows you to see the values associated with each specific date. You can also toggle between season to date and recent trend.

How do these tools work?
The Freeze Risk Tools graph hardiness temperature versus observed temperature for a several grape varieties, over a specific date range. It also estimates the stage of development.

Producers can use the tools to:
Determine the level of frost injury to crops due to sub-freezing temperatures
Monitor the level of freeze tolerance of crops through time
Track the phenological stage of development

How is our Frost Risk Tool different from others?
Other frost risk websites refer the user to use Growing Degree Day (GDD) tools, and are not crop or variety-specific. Our tool takes into account hardiness levels of different crops and plots it against projected and observed minimum and maximum temperature.