Farm Calls: Evidence-Based Agriculture and Full Moon Frosts

This week, Morris County Ag Agent Pete Nitzsche comments that North Jersey spring temperatures have farmers discussing the relationship between the occurrence of a full moon and frost.
There's good reason for concern. As Dave Robinson reports in his May 4, 2013 summary,

...low temperatures were at or below freezing at one or more locations on 16 April days. Six days saw a location fall to 25° or colder. The first of these days was the 2nd, when cold air drainage resulted in the valley locations of Walpack (Sussex) dropping to 18° and Pequest (Warren) 20°. On the 3rd, Pequest reached 21° and Kingwood (Hunterdon) 22°.

Radiation frosts happen when freezing conditions occur on clear nights with little or no wind, when the outgoing radiation is greater than the incoming, and cooling air temperature near the surface creates a stable temperature inversion near the ground. These same conditions create a crystal clear atmosphere, which makes a full moon appear exceptionally bright.

But, is there evidence that a frost is more likely to occur on a night with a full moon than one without?

Meteorologists vs Myth

Extension Specialist in Meteorology, Keith Arnesen, studied spring frosts during the months of April, May, and June for two representative NJ farming communities where he had daily temperature records for more than half a century. He also had the full moon dates for those three months during the 50-year period. The data presentation showed that a full moon does not accompany a greater likelihood of a frost.

Full Moon Does Not Increase Occurrence of  Frost Event

Base Farming Decisions on Short-term Weather Forecasts

Short-term farming decisions are better based on short-term weather forecasts than on moon phases. Agricultural weather advisories for New Jersey can be found at:

• Rutgers Weather Center AG Forecast
• Rutgers NJ Weather & Climate Network
• Network for Environmental and Weather Applications

Ag Agents and Extension Specialists with field experience know that access to ag weather advisories are important to NJ urban fringe farmers. A January 2013 article in Weather, Climate, and Society supports this view. Authors G. Frisvold and A. Murugesan found that the intensity of weather data use is greater among producers with diversified agricultural production. Diversified producers are more likely to use data for timing of planting, cultivation, and harvest. In addition, they found that weather data use is lower among producers with greater reliance on off-farm income. Producers who rated government risk-management programs as important also found more weather data types important and used weather data for more decisions. Access to satellite TV increased data use but access to the Internet did not.