UW Extension Ag Weather

Snowy Scene

NWS Co-Op Observer Reports

These weather data are maximum and minimum air temperature and precipitation, for the previous 24 hours, observed at about 7 am. The observations are made by a group of about 60 volunteers, who immediately transmit them to the National Weather Service Forecast Office in Sullivan, WI. Meteorologists there collect the readings and make them available on the Weather Service's computer system. We retrieve the data from McIDAS, a system created and maintained by the Space Science and Engineering Center of the University of Wisconsin-Madison. Until December 2003, the reports were referred to by the NWS as "OPU", for "Other Public Products"; they are now officially "HYD", for "hydrometeorological data".

Some of the observers providing these measurements are part of the National Weather Service's Cooperative Observation Program, and their data will be included in long-term records. Other observers are not official members of the Cooperative Program, and use their own equipment. Thus, averages published in the "Climate of Wisconsin" (about 8 months from now) may not agree with those derived from the daily summaries here.

Note that HYD reports are for the 24 hours preceding the date and time on which they are issued. So the January 2 report has January 1's weather, and so on.

January
SMTWThFSa
 123456
78910111213
14151617181920
21222324252627
28293031   
February
SMTWThFSa
    123
45678910
11121314151617
18192021222324
25262728   
March
SMTWThFSa
    123
45678910
11121314151617
18192021222324
25262728293031
April
SMTWThFSa
1234567
891011121314
15161718192021
22232425262728
2930     
May
SMTWThFSa
  12345
6789101112
13141516171819
20212223242526
2728293031  
June
SMTWThFSa
     12
3456789
10111213141516
17181920212223
24252627282930
July
SMTWThFSa
1234567
891011121314
15161718192021