Automated Weather Observing System (AWOS) stations are often grouped together with the ASOS stations, but they are not the same. Like the ASOS, the AWOS sensors primarily provide the aviation community with current weather observations. The data is also transmitted by phone lines or satellite uplinks for use by other agencies. The AWOS sites are either federally operated by the FAA or some of them are locally maintained by state agencies.[1]
The Iowa DOT kept an one minute interval archive of their data between 1995 and 1 April 2011. Due to communication changes, this archival was discontinued. You can download data from this archive at the links below. You can use this link for 5-10 minute interval data after 1 April 2011.
The IEM archives the routine METAR reports from this network at up to 5 minute intervals.