AWOS Sky Coverage Codes
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.
There does not appear to be a definitive published cross reference for these values, so the table below reflects an educated best-effort interpretation by Harry Hillaker and Daryl Herzmann.
Use this page as a lookup reference when working with the archived AWOS one-minute dataset. Code meanings should be treated as interpreted guidance, not an official vendor specification.
Sky Coverage Lookup Table
Archive reference| 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. |