| N | Total cloud cover |
| Nh | Amount of all the CL cloud present or, if no CL cloud is present, the amount of all the CM cloud present |
| Ns | Amount of individual cloud layer or mass whose genus is indicated by C |
| N' | Amount of cloud whose base is below the level of the station |
| Code figure | ||
|---|---|---|
| 0 | 0 | 0 |
| 1 | 1 okta or less, but not zero | 1/10 or less, but not zero |
| 2 | 2 oktas | 2/10 - 3/10 |
| 3 | 3 oktas | 4/10 |
| 4 | 4 oktas | 5/10 |
| 5 | 5 oktas | 6/10 |
| 6 | 6 oktas | 7/10 - 8/10 |
| 7 | 7 oktas or more, but not 8 oktas | 9/10 or more, but not 10/10 |
| 8 | 8 oktas | 10/10 |
| 9 | Sky obscured by fog and/or other meteorological phenomena | |
| / | Cloud cover is indiscernible for reasons other than fog or other meteorological phenomena, or observation is not made | |