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About the MRCC Frost/Freeze Guidance Project

How VIP members help forecastersWhat

The Midwestern Regional Climate Center (MRCC) is providing collaboration among weather forecasters, University Extension specialists, state climatologists, and other vegetation experts to improve communication about the state of vegetation and its susceptibility to potentially damaging low air temperatures. [ Brochure ]


Low temperatures during the growing season can cause devastating and lasting effects on vegetation. Climatologically determined dates for when the first or last potentially damaging freeze of a growing season occurs can be used as guidance for when forecasters should consider issuing awareness headlines to the community. However, not every plant is susceptible to the same low temperature threshold. Considerations for agriculture may be different from horticulture, nurseries, or home gardeners. Extreme or unusual seasons are often most dangerous because the weather does not conform well to the climatological dates of first or last freeze.

Therefore, forecasters are seeking ways in which they can augment their current resources for when to issue frost/freeze headlines with input from vegetation experts and operational online climate information.

While not all damage can be prevented, an advanced warning of air temperatures that may negatively affect susceptible vegetation can provide the opportunity for preventative action such as bringing plants indoors, covering vulnerable plants, or activating heaters.


Anyone interested in participating in this project as either a forecaster or someone who can provide information on the current state of local vegetation is welcome to subscribe to the project.

The effective potential of this project depends upon the effort of a diverse community of individuals who are both willing and interested in sharing their expertise in plant growth cycles, plant vulnerabilities, atmospheric forecasts, and climatology.  In order for a frost/freeze forecast headline to be beneficial, forecasters need to have the best guidance information possible on the state of the vegetative and climatological environment.

Subscription information
To subscribe to the project, simply:
   • Go to the Frost/Freeze registration page
   • Fill out the registration form and submit it
   • After receiving the confirmation page in your browser, you will be able to use the participants-only areas of the website
   • Subscription is automatically processed, and is available 24/7

To unsubscribe
While we don't want to see you go, if you need to unsubscribe, simply:
   • Send an email to
   • Put “signoff freeze-list” in the subject of the email message
   • Feedback is important to us; if you can share why you unsubscribed, please tell us in the body of the email
   • Unsubscribe requests will be processed during regular business hours

Being a subscriber allows access to both the frost/freeze guidance and freeze impact forms for submission and the master list of all fellow subscribers on the main webpage. There is an email listserv that subscribers automatically join that allows them to post and receive emails to and from the entire group.


For real-time climatological summary information of the current environment, the MRCC receives daily observational atmospheric data and synthesizes that data into graphical products.  Guidance from experts on local vegetation growing cycles and susceptibility is provided through online forms that advise forecasters whether or not a frost/freeze headline may be warranted for the vegetation of their expertise.

Through a simple 3-category guidance rating, these experts can indicate the following:

  • “Vegetation Not Susceptible” — There is little to no vegetation in the area that would be susceptible to low temperatures; the plants are all dormant. Therefore, should temperatures get below freezing, issuing a frost/freeze headline would be unnecessary
  • “Mixed Susceptibility” — While there is not a lot of susceptible vegetation in the local area, there are some plants (e.g., nurseries, home gardens, fruit trees) that are still present and could be damaged. Communicate with local experts and surrounding areas should low temperatures be in the forecast
  • “Vegetation Susceptible” —There is vegetation in the area that would be damaged should low (freezing) temperatures occur

Once submitted, forecasters can review these forms and refer to the “Vegetation Status” maps summarizing this data when considering whether or not to issue a frost/freeze headline when low temperatures are anticipated.  This information (both climatological and from vegetation experts) can also be used to communicate to neighboring forecast offices in order to provide a sense of spatial continuity and coherence from one region to another.

In addition, Freeze Impact Forms are available that should be utilized to submit any damage or other negative effects on vegetation after a frost/freeze event.


All tools and products for this project are available online at the Frost/Freeze Guidance main page. The items available on the project webpage include:

  • Static maps that are updated multiple times per day. Click here to see map run times.
  • A Freeze Map Interface with the most up-to-date information (GIS format) where users can turn on multiple layers, zoom in and out, get information about the data that went into the maps, and view guidance and impact reports
  • Online guidance and impact reporting forms (available only for subscribers to listserv)
  • List of subscribers to the project (available only for subscribers to listserv)

For more information on how to subscribe to the project, see the “Who” section above.