WMO CODE TABLE 4677

4677

ww Present weather reported from a manned weather station

ww = 00-49	No precipitation at the station at the time of observation
ww = 00-19	No precipitation, fog, ice 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 preceding hour

^* The expression "at the station" refers to a land station or a ship.

Code figure
00	Cloud development not observed or not observable	Characteristic change of the state of sky during the past hour
01	Clouds generally dissolving or becoming less developed
02	State of sky on the whole unchanged
03	Clouds generally forming or developing
04	Visibility reduced by smoke, e.g. veldt or forest fires, industrial smoke or volcanic ashes
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 wind at or near the station at the time of observation, but no well developed dust whirl(s) or sand whirl(s), and no duststorm or sandstorm seen
08	Well developed dust whirl(s) or sand whirl(s) seen at or near the station during the preceding hour or at the time ot 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	shallow fog or ice fog at the station, whether on land or sea, not deeper than about 2 metres on land or 10 metres at sea
12	More or less continuous
13	Lightning visible, no thunder heard
14	Precipitation within sight, not reaching the ground or the surface of the sea
15	Precipitation within sight, reaching the 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 the time of observation
19	Funnel cloud(s)^**

^** Tornado cloud or water-spout.

ww = 20-29

Precipitation, fog, ice fog or thunderstorm at the station during the preceding hour but not at the time of observation

Code figure
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)

^* Hail, small hail, snow pellets. French: grêle, grésil ou neige roulée.

ww = 30-39

Duststorm, sandstorm, drifting or blowing snow

Code figure
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 has 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 has increased during the preceding hour
36	Slight or moderate blowing snow	generally low (below eye level)
37	Heavy drifting snow	generally low (below eye level)
38	Slight or moderate blowing snow	generally high (above eye level)
39	Heavy drifting snow	generally high (above eye level)

ww = 40-49

Fog or ice fog at the time of observation

Code figure
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 the preceding hour
43	Fog or ice fog, sky invisible	has become thinner during the preceding hour
44	Fog or ice fog, sky visible	no appreciable change during the preceding hour
45	Fog or ice fog, sky invisible	no appreciable change during the preceding hour
46	Fog or ice fog, sky visible	has begun or has become thicker during the preceding hour
47	Fog or ice fog, sky invisible	has begun or has become thicker during the preceding hour
48	Fog, depositing rime, sky visible
49	Fog, depositing rime, sky invisible

ww = 50-99	precipitation at the station at the time of observation
ww = 50-59	Drizzle

Code figure
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 (dence)
58	Drizzle and rain, slight
59	Drizzle and rain, moderate or heavy

ww = 60-69

Rain

Code figure
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	heavy at time of observation
65	Rain, not freezing, continuous	heavy at time of observation
66	Rain, freezing, slight
67	Rain, freezing, moderate or heavy (dence)
68	Rain or drizzle and snow, slight
69	Rain or drizzle and snow, moderate or heavy

ww = 70-79 Solid precipitation not in showers

Code figure
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

ww = 80-99 Showery precipitation, or precipitation with current or recent thunderstorm

Code figure
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
91	Slight rain at time of observation	Thunderstorm during the preceding hour but not 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
95	Thunderstorm, slight or moderate, without hail^{** but with rain and/or snow at time of observation}	Thunderstorm 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

^* French: grêle.
^** Hail, small hail, snow pellets. French: grêle, grésil ou neige roulée