| Code figure | Technical specifications |
Code figure | Non-technical specifications |
| 0 |
No CH clouds |
0 |
No Cirrus, Cirrocumulus or Cirrostratus |
| 1 |
Cirrus fibratus, sometimes uncinus, not progressively invading the sky
|
1 |
Cirrus in the form of filaments, strands or hooks, not progressively invading the sky
|
| 2 |
Cirrus spissatus, in patches or entangled sheaves, which usually do not increase and sometimes
seem to be the remains of the upper part of a Cumulonimbus; or Cirrus castellanus or floccus
|
2 |
Dense Cirrus, in patches or entangled sheaves, which usually do not increase and sometimes seem
to be the remains of the upper part of a Cumulonimbus; or Cirrus with sproutings in the form of small
turrets or battlements, or Cirrus having the appearance of cumuliform tufts
|
| 3 |
Cirrus spissatus cumulonimbogenitus
|
3 |
Dense Cirrus, often in the form of an anvil, being the remains of the upper parts of Cumulonimbus
|
| 4 |
Cirrus uncinus or fibratus, or both, progressively invading the sky; they generally thicken as a whole
|
4 |
Cirrus in the form of hooks or of filaments, or both, progressively invading the sky; they generally
become denser as a whole
|
| 5 |
Cirrus (often in bands) and Cirrostratus, or Cirrostratus alone, progressively invading the sky;
they generally thicken as a whole, but the continuous veil does not reach 45 degrees above the horizon
|
5 |
Cirrus (often in bands converging towards one point or two opposite points of the horizon) and Cirrostratus,
or Cirrostratus alone; in either case, they are progressively invading the sky, and generally growing denser
as a whole, but the continuous veil does not reach 45 degrees above the horizon
|
| 6 |
Cirrus (often in bands) and Cirrostratus, or Cirrostratus alone, progressively invading the sky;
they generally thicken as a whole; the continuous veil extends more than 45 degrees above the horizon,
without the sky being totally covered
|
6 |
Cirrus (often in bands converging towards one point or two opposite points of the horizon) and Cirrostratus,
or Cirrostratus alone; in either case, they are progressively invading the sky, and generally growing denser
as a whole; the continuous veil extends more than 45 degrees above the horizon, without the sky being totally covered
|
| 7 |
Cirrostratus covering the whole sky
|
7 |
Veil of Cirrostratus covering the celestial dome
|
| 8 |
Cirrostratus not progressively invading the sky and not entirely covering it
|
8 |
Cirrostratus not progressively invading the sky and not completely covering the celestial dome
|
| 9 |
Cirrocumulus alone, or Cirrocumulus predominant among the CH clouds
|
9 |
Cirrocumulus alone, or Cirrocumulus accompanied by Cirrus or Cirrostratus, or both, but Cirrocumulus is predominant
|
| / |
CH clouds invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena,
or because of a continuous layer of lower clouds
|
/ |
Cirrus, Cirrocumulus and Cirrostratus invisible owing to darkness, fog, blowing dust or sand, or other similar
phenomena, or more often because of the presence of a continuous layer of lower clouds
|