| WW Code |
WW Symbol |
WW Description |
| 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 |
No symbol |
Cloud development not observed or observable
(characteristic state of sky during the past hour)
|
| 01 |
No symbol |
Clouds dissolving or becoming less developed
(characteristic state of sky during the past hour)
|
| 02 |
No symbol |
State of sky on the whole unchanged
|
| 03 |
No symbol |
Clouds generally forming or developing
(characteristic state of sky during the past hour)
|
| 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 |
 |
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
|
| 10 |
 |
Mist
|
| 11 |
 |
Patches of shallow fog or ice fog, less than 2m on land or 10m at sea
|
| 12 |
 |
More or less continuous shallow fog or ice fog, less than 2m on land or
10m at sea
|
| 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 preceeding hour or at time
of observation)
|
| 19 |
 |
Tunnel clouds or tuba
(at or within sight of the station during the preceeding hour or at time
of observation)
|
| 20-29 |
|
Precipitation, fog, ice fog or thunderstorm at the station
during the preceeding hour but not at the time of observation
|
| 20 |
 |
Drizzle (not freezing) or snow grains
(not falling as showers)
|
| 21 |
 |
Rain (not freezing)
(not falling as showers)
|
| 22 |
 |
Snow
(not falling as showers)
|
| 23 |
 |
Rain and snow or ice pellets
(not falling as showers)
|
| 24 |
 |
Freezing drizzle or freezing rain
(not falling as showers)
|
| 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)
|
| 30-39 |
|
Duststorm, sandstorm, drifting or blowing snow
|
| 30 |
 |
Slight or moderate duststorm or sandstorm -
Has decreased in the preceding hour.
|
| 31 |
 |
Slight or moderate duststorm or sandstorm -
No appreciable change during the preceding hour.
|
| 32 |
 |
Slight or moderate duststorm or sandstorm -
Has begun or increased during the preceding hour.
|
| 33 |
 |
Severe duststorm or sandstorm -
Has decreased in the preceding hour.
|
| 34 |
 |
Severe duststorm or sandstorm -
No appreciable change during the preceding hour.
|
| 35 |
 |
Severe duststorm or sandstorm -
Has begun or increased during the preceding hour.
|
| 36 |
 |
Slight or moderate drifting snow (generally low)
|
| 37 |
 |
Heavy drifting snow (below eye level)
|
| 38 |
 |
Slight or moderate blowing snow (generally high)
|
| 39 |
 |
Heavy blowing snow (above eye level)
|
| 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
(has become thinner during preceding hour)
|
| 44 |
 |
Fog or ice fog, sky visible
(no appreciable change during preceding hour)
|
| 45 |
 |
Fog or ice fog, sky obscured
(no appreciable change during preceding hour)
|
| 46 |
 |
Fog or ice fog, sky visible
(has begun or become thicker during preceding hour)
|
| 47 |
 |
Fog or ice fog, sky obscured
(has begun or become thicker during preceding hour)
|
| 48 |
 |
Fog or ice fog, sky visible
|
| 49 |
 |
Fog or ice fog, sky obscured
|
| 50-59 |
|
Drizzle
|
| 50 |
 |
Drizzle, not freezing, intermittent
(slight at time of observation)
|
| 51 |
 |
Drizzle, not freezing, continuous
(slight at time of observation)
|
| 52 |
 |
Drizzle, not freezing, intermittent
(moderate at time of observation)
|
| 53 |
 |
Drizzle, not freezing, continuous
(moderate at time of observation)
|
| 54 |
 |
Drizzle, not freezing, intermittent
(heavy (dense) at time of observation)
|
| 55 |
 |
Drizzle, not freezing, continuous
(heavy (dense) at time of observation)
|
| 56 |
 |
Drizzle, freezing, slight
|
| 57 |
 |
Drizzle, freezing, moderate or heavy (dense)
|
| 58 |
 |
Drizzle and rain, slight
|
| 59 |
 |
Drizzle and rain, moderate or heavy
|
| 60-69 |
|
Rain
|
| 60 |
 |
Rain, not freezing, intermittent
(slight at time of observation)
|
| 61 |
 |
Rain, not freezing, continuous
(slight at time of observation)
|
| 62 |
 |
Rain, not freezing, intermittent
(moderate at time of observation)
|
| 63 |
 |
Rain, not freezing, continuous
(moderate at time of observation)
|
| 64 |
 |
Rain, not freezing, intermittent
(moderate at time of observation)
|
| 65 |
 |
Rain, not freezing, continuous
(heavy at time of observation)
|
| 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
|
| 70-79 |
|
Solid precipitation not in showers
|
| 70 |
 |
Intermittent fall of snowflakes
(slight at time of observation)
|
| 71 |
 |
Continuous fall of snowflakes
(slight at time of observation)
|
| 72 |
 |
Intermittent fall of snowflakes
(moderate at time of observation)
|
| 73 |
 |
Continuous fall of snowflakes
(moderate at time of observation)
|
| 74 |
 |
Intermittent fall of snowflakes
(heavy at time of observation)
|
| 75 |
 |
Continuous fall of snowflakes
(heavy at time of observation)
|
| 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
|
| 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 |
 |
Shower(s) of snow pellets or small hail with or without rain or rain and
snow mixed (moderate or heavy)
|
| 89 |
 |
Shower(s) of hail, with or without rain or rain and snow mixed, not
associated with thunder (slight)
|
| 90 |
 |
Shower(s) of hail, with or without rain or rain and snow mixed, not
associated with thunder (moderate or heavy)
|
| 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 at time of observation
|
| 94 |
 |
Moderate or heavy snow, or rain and snow mixed, or hail at time of
observation
|
| 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
|
