The Colorado Climate Center operates a network of over 30 weather stations scattered throughout the state, primarily in irrigated agricultural areas. The stations have been operating for up to a five year period, and each location monitors soil temperature on an hourly and daily basis. Soil temperature is measured at 2.5 and 15 cm depths. The data from these weather stations will be summarized and evaluated. Duration of sub-freezing temperatures (consecutive days) and length and number of freezing and thawing periods will be compared as a function of elevation and latitude. Passage of time from time of freezing at the shallower depth to time of freezing at the deeper depth will be determined. Variation from year to year will also be surveyed to determine a degree of predictability of time of first freeze and last freeze. These dates and their probabilities will be utilized to recommend planting and harvest times across the state. The freezing and thawing dates could also be used for selection of varieties with optimum growing season length.

Jessica G. Davis
Department of Soil and Crop Sciences
Colorado State University
Fort Collins, CO 80523-1170   U.S.A.
Phone (970)491-1913
FAX (970)491-0564
Email: jgdavis@lamar.colostate.edu