Where does this information come from?

RWIS - Roadway Weather Information System
These sensors are located in and along Iowa's Interstate and primary roads. The RWIS network of sensors is designed to provide Iowa Department of Transportation Maintenance employees the specific weather information they need about the roadway.   With specific roadway-based weather information, better decisions and  treatment strategies for snow and ice control are possible. The information is also a valuable aid in summer activities where weather can affect the timing and completion of projects such as pavement patching, mowing, herbicide spraying, etc.

AWOS - Automated Weather Observing System
These sensors are part of the Iowa Aviation Weather System and are located at airports across the state. This system was designed and built primarily to assist pilots in assessing weather conditions.

Regional Forecasts
These regional forecasts are excerpts from a winter forecast received by the Iowa Department of Transportation from a private contractor. The forecasts are used as a tool to plan the actions of the Maintenance crews on Iowa's Interstate and primary highways when winter weather threatens.