| WW=00-19 | No precipitation, fog,(except for 11 and 12), duststorm, sandstorm, drifting or blowing snow at the station at the time of observation or, except for 09 and 17, during the preceeding hour
|
|
| 00 | Cloud development not observed or observable | characteristic state of sky during the past hour
|
| 01 | Clouds dissolving or becoming less developed
|
| 02 | State of sky on the whole unchanged
|
| 03 | Clouds generally forming or developing
|
| 04 | Visibility reduced by smoke haze
|
| 05 | Haze
|
| 06 | Widespread dust in suspension in the air, not raised by
wind at or near the station at the time of observation.
|
| 07 | Dust or sand raised by the wind at or near the station at
the time of the observation, but no well-developed dust
whirl(s), and no sandstorm seen: or, in the case of ships,
blowing spray at the station
|
| 08 | Well developed dust whirl(s) or sand whirl(s) seen
at or near the station during the preceding hour or
at the time of observation, but no duststorm or sandstorm
|
| 09 | Duststorm or sandstorm within sight at the time of
observation, or at the station during the preceding hour
|
| 10 | Mist
|
| 11 | Patches of | shallow fog or ice fog, less than 2 m on land or 10 m at sea
|
| 12 | More or less continuous
|
| 13 | Lightning visible, no thunder heard
|
| 14 | Precipitation within sight, not reaching the ground or surface of sea
|
| 15 | Precipitation within sight, reaching ground or the
surface of the sea, but distant, i.e. estimated to
be more than 5 km from the station
|
| 16 | Precipitation within sight, reaching the ground or
the surface of the sea, near to, but not at the station
|
| 17 | Thunderstorm, but no precipitation at the time of observation
|
| 18 | Squalls | at or within sight of the station during the preceding hour or at time of observation
|
| 19 | Funnel cloud(s) or tuba
|
|
|
| WW=20-29 | Precipitation, fog, ice fog or thunderstorm at the station during
the preceeding hour but not at the time observation
|
| 20 | Drizzle (not freezing) or snow grains | Not falling as shower(s)
|
| 21 | Rain (not freezing)
|
| 22 | Snow
|
| 23 | Rain and snow or ice pellets
|
| 24 | Freezing drizzle or freezing rain
|
| 25 | Shower(s) of rain
|
| 26 | Shower(s) of snow, or of rain and snow
|
| 27 | Shower(s) of hail, or of rain and hail
|
| 28 | Fog or ice fog
|
| 29 | Thunderstorm (with or without precipitation)
|
|
|
| WW=30-39 | Duststorm, sandstorm, drifting or blowing snow
|
| 30 | Slight or moderate duststorm or sandstorm | has decreased during the preceding hour
|
| 31 | no appreciable change during the preceding hour
|
| 32 | has begun or increased during the preceding hour
|
| 33 | Severe duststorm or sandstorm | has decreased during the preceding hour
|
| 34 | no appreciable change during the preceding hour
|
| 35 | has begun or increased during the preceding hour
|
| 36 | Slight or moderate drifting snow | Generally low (below eye level)
|
| 37 | Heavy drifting snow
|
| 38 | Slight or moderate blowing snow | Generally high (above eye level)
|
| 39 | Heavy blowing snow
|
|
|
| WW=40-49 | Fog or ice fog at the time of observation
|
| 40 | Fog or ice fog at a distance at the time of observation, but not at the
station during the preceding hour, the fog or ice fog extending to a level above that of the observer
|
| 41 | Fog or ice fog in patches
|
| 42 | Fog or ice fog, sky visible | has become thinner during preceding hour
|
| 43 | Fog or ice fog, sky obscured
|
| 44 | Fog or ice fog, sky visible | no appreciable change during the preceding hour
|
| 45 | Fog or ice fog, sky obscured
|
| 46 | Fog or ice fog, sky visible | has begun or has become thicker during the preceding hour
|
| 47 | Fog or ice fog, sky obscured
|
| 48 | Fog or ice fog, sky visible
|
| 49 | Fog or ice fog, sky obscured
|
|
|
| WW=50-59 | Drizzle
|
| 50 | Drizzle, not freezing, intermittent | slight at time of observation
|
| 51 | Drizzle, not freezing, continuous
|
| 52 | Drizzle, not freezing, intermittent | moderate at time of observation
|
| 53 | Drizzle, not freezing, continuous
|
| 54 | Drizzle, not freezing, intermittent | heavy (dense) at time of observation
|
| 55 | Drizzle, not freezing, continuous
|
| 56 | Drizzle, freezing, slight
|
| 57 | Drizzle, freezing, moderate or heavy (dense)
|
| 58 | Drizzle and rain, slight
|
| 59 | Drizzle and rain, moderate or heavy
|
|
|
| WW=60-69 | Rain
|
| 60 | Rain, not freezing, intermittent | Slight at time of observation
|
| 61 | Rain, not freezing, continuous
|
| 62 | Rain, not freezing, intermittent | Moderate at time of observation
|
| 63 | Rain, not freezing, continuous
|
| 64 | Rain, not freezing, intermittent | Heavy at time of observation
|
| 65 | Rain, not freezing, continuous
|
| 66 | Rain, freezing, slight
|
| 67 | Rain, freezing, moderate or heavy
|
| 68 | Rain or drizzle and snow, slight
|
| 69 | Rain or drizzle and snow, moderate or heavy
|
|
|
| WW=70-79 | Solid precipitation not in showers
|
| 70 | Intermittent fall of snowflakes | slight at time of observation
|
| 71 | Continuous fall of snowflakes
|
| 72 | Intermittent fall of snowflakes | moderate at time of observation
|
| 73 | Continuous fall of snowflakes
|
| 74 | Intermittent fall of snowflakes | heavy at time of observation |
| 75 | Continuous fall of snowflakes
|
| 76 | Diamond dust (with or without fog)
|
| 77 | Snow grains (with or without fog)
|
| 78 | Isolated star-like snow crystals (with or without fog)
|
| 79 | Ice pellets
|
|
|
| WW=80-99 | Showery precipitation, or precipitation with current or recent thunderstorm
|
| 80 | Rain shower(s), slight
|
| 81 | Rain shower(s), moderate or heavy
|
| 82 | Rain shower(s), violent
|
| 83 | Shower(s) of rain and snow mixed, slight
|
| 84 | Shower(s) of rain and snow mixed, moderate or heavy
|
| 85 | Snow shower(s), slight
|
| 86 | Snow shower(s), moderate or heavy
|
| 87 | Shower(s) of snow pellets or small hail with or without rain or rain and snow mixed | slight
|
| 88 | moderate or heavy
|
| 89 | Shower(s) of hail, with or without rain or rain and snow mixed, not associated with thunder | slight
|
| 90 | moderate or heavy
|
|
|
| WW=91-94 | Thunderstorm during the preceeding hour but not at time of observation
|
| 91 | Slight rain at time of observation
|
| 92 | Moderate or heavy rain at time of observation
|
| 93 | Slight snow, or rain and snow mixed, or hail at time of observation
|
| 94 | Moderate or heavy snow, or rain and snow mixed, or hail at time of observation
|
|
|
| WW=95-99 | Thunderstorm at time of observation
|
| 95 | Thunderstorm, slight or moderate, without hail but with rain and or snow at time of observation
|
| 96 | Thunderstorm, slight or moderate, with hail at time of observation
|
| 97 | Thunderstorm, heavy, without hail but with rain and or snow at time of observation
|
| 98 | Thunderstorm combined with duststorm or sandstorm at time of observation
|
| 99 | Thunderstorm, heavy, with hail at time of observation
|
|
|