The Iowa DOT provides the IEM with an archive of 1 minute observations from their AWOS network. This archive contains numerically coded values for sky coverage. Unfortunately, there does not appear to be a definitive cross reference to match these values up to something humans can understand (ex. overcast). Here is our (Harry Hillaker and Daryl Herzmann) educated guess at a cross reference to what the sky coverage codes mean that are found in the archive.
| Code | Translated Code: | Meaning |
|---|---|---|
| 0 | NOREPORT | No report, since lower cloud layers are obstructing. |
| 1 | SCATTERED | Scattered (10% to 50% coverage) |
| 2 | BROKEN | Broken (60% to 90% coverage) |
| 4 | OVERCAST | Overcast (More than 90% coverage) |
| 8 | OBSCURATION | Full obscuration (no ceiling or cloud amount available) |
| 17 | OBSCURATION | Partial obscuration, lowest cloud layer is scattered. |
| 18 | OBSCURATION | Partial obscuration, lowest cloud layer is broken. |
| 20 | OBSCURATION | Partial obscuration, lowest cloud layer is overcast. |
| 32 | INDEFINITE | Indefinite ceiling (no cloud cover amount available?) |
| 64 | CLEAR | No clouds below 12000 feet |
| 128 | FEW | Few (less than 10% coverage) |
| 255 | MISSING | Missing (sky condition not measured). |
| * | UNKNOWNCODE | All other values that may appear in the database. |