About Daily Weather Maps
Weather summary maps are produced daily from data collected by the Illinois Climate Network. The information is derived from automated polling of sensors (most at 10-second intervals) and downloaded to an ISWS computer once a day. Contoured maps are produced of the data variables listed below. Site values for each map are included in an accompanying table. Unless specified differently, the format of each variable is based on hourly averages or totals, computed from the 10-second polling data at each site.
All data are provisional. Data processing includes automated quality control and Surfer objective analysis contouring routines. Communication failure with stations will generate a missing value indicator, "M", to be displayed in the table. Spurious values occasionally are included as actual data. Every attempt is made to edit inaccurate and missing data in a timely manner.
Plots are included for:
- Maximum and Minimum Air Temperatures - The warmest and coldest temperatures recorded at each site each calendar day from
the 10-sec polling of data (CST).
- Maximum Wind Gust - A direct readout from internal instrument storage of the highest recorded wind gust monitored at
intervals of every tenth of a second (1/10 sec).
- Average Wind Speed and Average Dew Point Temperature - A daily arithmetic average of each variable.
- Average Wind Direction - A daily vector average of all recorded wind direction values.
- Solar Radiation and Potential Evapotranspiration - 24-hour totals of each variable.
- Precipitation Data - Recorded at each polling interval as a current gage total (i.e. the amount of fluid in the gage at the
time of observation). Totals on maps are computed by subtracting "yesterday's" midnight total from "today's" midnight total.
Note:
Dew point temperature and potential evapotranspiration values are computed variables added to the data stream using
hourly averages of air temperature, relative humidity, wind speed, barometric pressure, and solar radiation. Time used with all
ICN data is Central Standard Time year round.