The name M1M2 refers to month-1 (which is the current calendar month) and month-2 (the following calendar month). The web tool was developed to provide users with data and images that facilitate trading Degree Day Futures on the Chicago Mercantile Exchange (CME).

Each day, ensemble forecasts are downloaded from the U.S. National Centers for Environmental Prediction (NCEP) web site and processed, with historical, climatological and current temperature data to produce month-end projections of accumulated Heating Degree Days (HDDs) and Cooling Degree Days (CDDs).

In addition to HDDs and CDDs, 850 hPa temperature, 500 hPa geopotential heights and surface temperature are processed into M1 and M2 monthly averages. Typically, the degree day accumulations and monthly averages are shown as spatial patterns of absolute values and standardized anomalies, and as station values for 24 cities distributed across the U.S., including the 15 CME cities.

The the web tool is fully functional as of 02/01/2005. Ensemble forecast images are now available as animated images.