Water and Atmospheric Resources Monitoring Program - , Illinois State Water Survey

Water and Atmospheric Resources Monitoring Program (WARM)

Crop Degree-Day Calculator: Background


Daily weather data for this program are collected by the Water and Atmospheric Resources Monitoring (WARM) Program. Weather data are obtained from a 19-station array of automated weather stations in Illinois, operated by WARM, called the Illinois Climate Network or ICN (Hollinger et al. 1994).

Two growing degree-day total algorithms have been developed. One algorithm is linked specifically to the growth of corn, or "corn growing degree-days". This process compares the daily mean temperature at a particular site to a base temperature of 50° F with the restrictions that daily maximum temperatures above 86° F are set to 86° F and daily minimum temperatures below 50° F are set to 50° F. The second algorithm is designed for cold weather crops and uses a base temperature of 40° F for initiation of crop development, but with no temperature development threshold restrictions.

One- and two-week projections are presented and are based on the past 11 years of climate data (Easterling et al., 1990) at each ICN site. Daily maps of actual degree-day accumulations and projections are provided to indicate the statewide degree-day totals as the growing season progresses.

Quality control of weather data is a high priority. However, degree-day data based on the most recent information must be considered as provisional because data are provided here early each day through a totally automated process. Sensor malfunctions at weather stations, as well as communication and power interruptions at the sites, do occur, any of which may influence downloaded data. These occurrences could result in spurious degree day accumulations prior to manual quality control verification and needed data edits.

References:

Easterling, W. E. , J. R. Angel, and S. A. Kirsh, 1990. The Appropriate Use of Climatic Information in Illinois Natural-Gas Utility Weather-Normalization Techniques. Illinois State Water Survey Report of Investigation 112, Champaign, Illinois, 31 pp.

Hollinger, S. E., Reinke, B. C., and Peppler, R. A., 1994. Illinois Climate Network: Site Descriptions, Instrumentation, and Data Management, Illinois State Water Survey Circular 178, Champaign, Illinois, 63 pp.

Gilmore and Rogers, 1958. Heat Units as a Method of Measuring Maturity in Corn. Agronomy Journal. Vol 50, no 9. 611-615.

Illinois State Water Survey

2204 Griffith Dr., MC-674
Champaign, IL 61820-7463
217-333-2210
Email us with questions or comments.

 

© 2022 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois State Water Survey.
Terms of use | Privacy Policy | Web Administrator.