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Weather Symbols & Code Figures

The WMO code figures, weather symbols and detailed descriptions presented on this page are used extensively in the Station Weather Plot and SYNOP Code Form.

Pressure Trend

WMO Code Table 0200, characteristic of pressure tendency during the three hours preceding the time of observation.

Code figures 0, 1, 3, 5, 6 and 8 are not used by an automatic weather station.

Code Figure	Weather Symbol	Description
0		Increasing then decreasing, atmospheric pressure the same or higher than three hours ago
1		Increasing then steady or increasing then increasing more slowly, atmospheric pressure now higher than three hours ago
2		Increasing steadily or unsteadily, atmospheric pressure now higher than three hours ago
3		Decreasing or steady then increasing or increasing then increasing more rapidly, atmospheric pressure now higher than three hours ago
4		Steady, atmospheric pressure the same as three hours ago
5		Decreasing then increasing, atmospheric pressure the same or lower than three hours ago
6		Decreasing then steady or decreasing then decreasing more slowly, atmospheric pressure now lower than three hours ago
7		Decreasing steadily or unsteadily, atmospheric pressure now lower than three hours ago
8		Steady or increasing then decreasing or decreasing then decreasing more rapidly, atmospheric pressure now lower than three hours ago

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High Level Cloud

WMO Code Table 0509, clouds of genera cirrus, cirrocumulus and cirrostratus.

Code Figure	Weather Symbol	Description
0		No high level cloud
1		Cirrus in filaments or hooks not progressively invading the sky
2		Dense cirrus
3		Dense cirrus from cumulonimbus
4		Cirrus progressively invading the sky
5		Cirrostratus increasing but below 45° elevation
6		Cirrostratus increasing and above 45° elevation
7		Cirrostratus covering the whole sky
8		Cirrostratus neither progressively invading the sky nor entirely covering it
9		Cirrocumulus
/		High level cloud obscured for any reason

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Low Level Cloud

WMO Code Table 0513, clouds of genera stratocumulus, stratus, cumulus and cumulonimbus.

Code Figure	Weather Symbol	Description
0		No low level cloud
1		Small cumulus
2		Cumulus of moderate or strong vertical development
3		Cumulonimbus without anvil
4		Stratocumulus from spreading out of cumulus
5		Stratocumulus not from the spreading of cumulus
6		Stratus
7		Stratus fractus and cumulus fractus of bad weather
8		Cumulus and stratocumulus at different heights
9		Cumulonimbus with anvil
/		Low level cloud obscured for any reason

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Middle Level Cloud

WMO Code Table 0515, clouds of genera altocumulus, altostratus and nimbostratus.

Code Figure	Weather Symbol	Description
0		No middle level cloud
1		Thin altostratus
2		Thick altostratus or nimbostratus
3		Semitransparent altocumulus
4		Altocumulus continually changing shape — lenticular altocumulus
5		Altocumulus progressively invading the sky
6		Altocumulus from the spreading out of cumulus
7		Altocumulus at more than one level or thick altocumulus in a single layer
8		Altocumulus with tufts or sproutings
9		Altocumulus of a chaotic sky
/		Middle level cloud obscured for any reason

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Base of Lowest Cloud

WMO Code Table 1600, height above surface of the base of the lowest cloud seen.

Code Figure	Description
0	0 to 50 m	(0 to 150 ft)
1	50 to 100 m	(150 to 300 ft)
2	100 to 200 m	(300 to 600 ft)
3	200 to 300 m	(600 to 1,000 ft)
4	300 to 600 m	(1,000 to 2,000 ft)
5	600 to 1,000 m	(2,000 to 3,000 ft)
6	1,000 to 1,500 m	(3,000 to 5,000 ft)
7	1,500 to 2,000 m	(5,000 to 6,500 ft)
8	2,000 to 2,500 m	(6,500 to 8,000 ft)
9	2,500 m or more, or no low or middle cloud
/	Height unknown due to sky obscured

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Evaporation Instrumentation

WMO Code Table 1806, indicator for type of evaporation instrument.

Code figures 5, 6, 7, 8 and 9 refer to evapotranspiration (water loss from plants) and are omitted from this table.

Code Figure	Description
0	USA Open Pan without cover
1	USA Open Pan with mesh cover
2	GGI-3000 evaporimeter (sunken)
3	20-m2 tank
4	Other
5	Rice
6	Wheat
7	Maize
8	Sorghum
9	Other crops

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Inclusion of Precipitation Data

WMO Code Table 1819, indicator for inclusion or omission of precipitation data.

Code Figure	Description
0	Reported in Sections 1 and 3
1	Reported in Section 1
2	Reported in Section 3
3	Not reported in Sections 1 and 3, amount = 0
4	Not reported in Sections 1 and 3, amount not available

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Source and Units of Wind Speed

WMO Code Table 1855, indicator for source and units of wind speed.

Code figure / is included in the table as a local variation due to the anemometer not being installed.

Code Figure	Description
0	Wind speed estimated in metres per second
1	Wind speed from anemometer in metres per second
2	Wind speed estimated in knots
3	Wind speed from anemometer in knots
/	Omitted, data not available

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Inclusion of Present and Past Weather

WMO Code Table 1860, indicator for type of station operation and for present and past weather data.

Code Figure	Description	Station Operation
1	Included	Manned
2	Omitted, no significant weather to report	Manned
3	Omitted, data not available	Manned
4	Included, using Code Table 4677 and 4561	Automatic
5	Omitted, no significant weather to report	Automatic
6	Omitted, data not available	Automatic
7	Included, using Code Table 4680 and 4531	Automatic

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Amount of Cloud

WMO Code Table 2700, total cloud cover & amount of lowest cloud.

The station circle is at the centre of the station plot and is represented by the symbol for total cloud cover. All other symbols and data are plotted around the station circle.

Code Figure	Weather Symbol	Description
0		No cloud
1		1 okta (eighth) of cloud or less, but not zero
2		2 oktas of cloud
3		3 oktas of cloud
4		4 oktas of cloud (half the sky covered)
5		5 oktas of cloud
6		6 oktas of cloud
7		7 oktas of cloud
8		8 oktas of cloud (sky completely covered)
9		Sky obscured
/		No observation made

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Sign of Temperature

WMO Code Table 3845, indicator for sign of temperature.

Code Figure	Description
0	Positive or zero
1	Negative

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Rainfall Period

WMO Code Table 4019, duration of period of reference for amount of precipitation, ending at the time of the report.

Code Figure	Description
1	Total precipitation during the 6 hours preceding the observation
2	Total precipitation during the 12 hours preceding the observation
3	Total precipitation during the 18 hours preceding the observation
4	Total precipitation during the 24 hours preceding the observation
5	Total precipitation during the 1 hour preceding the observation
6	Total precipitation during the 2 hours preceding the observation
7	Total precipitation during the 3 hours preceding the observation
8	Total precipitation during the 9 hours preceding the observation
9	Total precipitation during the 15 hours preceding the observation

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Horizontal Visibility

WMO Code Table 4377, horizontal visibility at surface.

Code Figure	Description
00	< 0.1 km
01 ... 50	0.1 to 5.0 km, in increments of 0.1 km
56 ... 80	6 to 30 km, in increments of 1 km
81 ... 88	35 to 70 km, in increments of 5 km
89	> 70 km

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Past Weather

WMO Code Table 4561, past weather reported from a manned weather station.

Code Figure	Weather Symbol	Description
0		Cloud covering 1/2 or less of the sky throughout the appropriate period
1		Cloud covering more than 1/2 of the sky during part of the appropriate period and covering 1/2 or less during part of the period
2		Cloud covering more than 1/2 of the sky throughout the appropriate period
3		Sandstorm, duststorm or blowing snow
4		Fog or ice fog or thick haze
5		Drizzle
6		Rain
7		Snow, or rain and snow mixed
8		Shower(s)
9		Thunderstorm(s) with or without precipitation

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Present Weather

WMO Code Table 4677, present weather reported from a manned weather station.

Code Figure	Weather Symbol	Description
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 during the preceding hour (except 09 and 17)
00		Cloud development not observed or not observable
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. grassland 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 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 at the station, not deeper than about 2 metres
12		More or less continuous shallow fog or ice fog at the station, not deeper than about 2 metres
13		Lightning visible, no thunder heard
14		Precipitation within sight, not reaching the ground
15		Precipitation within sight and reaching the ground, but estimated to be more than 5 km from the station
16		Precipitation within sight and reaching the ground, 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) at or within sight of the station during the preceding hour or at the time of observation
20 - 29		Precipitation, fog, ice-fog or thunderstorm at the station during the preceding hour but not at the time of observation
20		Drizzle (not freezing) or snow grains during the preceding hour but not at the time of observation
21		Rain (not freezing) during the preceding hour but not at the time of observation
22		Snow during the preceding hour but not at the time of observation
23		Rain and snow or ice pellets during the preceding hour but not at the time of observation
24		Freezing drizzle or freezing rain during the preceding hour but not at the time of observation
25		Shower(s) of rain during the preceding hour but not at the time of observation
26		Shower(s) of snow, or of rain and snow during the preceding hour but not at the time of observation
27		Shower(s) of hail or of rain and hail during the preceding hour but not at the time of observation
28		Fog or ice fog during the preceding hour but not at the time of observation
29		Thunderstorm (with or without precipitation) during the preceding hour but not at the time of observation
30 - 39		Duststorm, sandstorm, drifting or blowing snow
30		Slight or moderate duststorm or sandstorm - has decreased during 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 has increased during the preceding hour
33		Severe duststorm or sandstorm - has decreased during the preceding hour
34		Severe duststorm or sandstorm – no appreciable change during the preceding hour
35		Severe duststorm or sandstorm - has begun or has increased during the preceding hour
36		Slight or moderate drifting snow, generally below eye level
37		Heavy drifting snow, generally below eye level
38		Slight or moderate blowing snow, generally above eye level
39		Heavy blowing snow, generally 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 the preceding hour
43		Fog or ice fog, sky invisible, has become thinner during the preceding hour
44		Fog of 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
50 - 59		Drizzle at the station at the time of observation
50		Slight intermittent drizzle (not freezing) at the time of observation
51		Slight continuous drizzle (not freezing) at the time of observation
52		Moderate intermittent drizzle (not freezing) at the time of observation
53		Moderate continuous drizzle (not freezing) at the time of observation
54		Heavy intermittent drizzle (not freezing) at the time of observation
55		Heavy continuous drizzle (not freezing) at the time of observation
56		Slight drizzle (freezing) at the time of observation
57		Moderate or heavy drizzle (freezing) at the time of observation
58		Slight drizzle and rain at the time of observation
59		Moderate or heavy drizzle at the time of observation
60 - 69		Rain at the station at the time of observation
60		Slight intermittent rain (not freezing) at the time of observation
61		Slight continuous rain (not freezing) at the time of observation
62		Moderate intermittent rain (not freezing) at the time of observation
63		Moderate continuous rain (not freezing) at the time of observation
64		Heavy intermittent rain (not freezing) at the time of observation
65		Heavy continuous rain (not freezing) at the time of observation
66		Slight rain (freezing)
67		Moderate or heavy rain (freezing)
68		Slight rain or drizzle and snow
69		Moderate or heavy rain or drizzle and snow
70 - 79		Solid precipitation not in showers at the station at the time of observation
70		Slight intermittent fall of snowflakes at the time of observation
71		Slight continuous fall of snowflakes at the time of observation
72		Moderate intermittent fall of snowflakes at the time of observation
73		Moderate continuous fall of snowflakes at the time of observation
74		Heavy intermittent fall of snowflakes at the time of observation
75		Heavy continuous fall of snowflakes at the 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 at the station at the time of observation
80		Slight rain shower(s)
81		Moderate or heavy rain shower(s)
82		Violent rain shower(s)
83		Slight shower(s) of rain and snow mixed
84		Moderate or heavy shower(s) of rain and snow mixed
85		Slight snow shower(s)
86		Moderate or heavy snow shower(s)
87		Slight shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed
88		Moderate or heavy shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed
89		Slight shower(s) of hail with or without rain or rain and snow mixed, not associated with thunder
90		Moderate or heavy shower(s) of hail with or without rain or rain and snow mixed, not associated with thunder
91		Slight rain at the time of observation, thunderstorm during the preceding hour but not at the time of observation
92		Moderate or heavy rain at the time of observation, thunderstorm during the preceding hour but not at the time of observation
93		Slight snow, or rain and snow mixed or hail at the time of observation, thunderstorm during the preceding hour but not at the time of observation
94		Moderate or heavy snow, or rain and snow mixed or hail at the time of observation, thunderstorm during the preceding hour but not at the time of observation
95		Slight or moderate thunderstorm without hail, but with rain and/or snow at the time of observation
96		Slight or moderate thunderstorm with hail at the time of observation
97		Heavy thunderstorm without hail, but with rain and/or snow at the time of observation
98		Thunderstorm combined with duststorm or sandstorm at the time of observation
99		Heavy thunderstorm with hail at the time of observation

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Wind Direction

Wind direction is represented by a line extending from the station circle towards the true direction from which the wind is blowing.

Calm is represented by a circle surrounding the station circle.

Compass Point	Description	Compass Point	Description
N	349° - 11°	S	169° - 191°
NNE	12° - 33°	SSW	192° - 213°
NE	34° - 56°	SW	214° - 236°
ENE	57° - 78°	WSW	237° - 258°
E	79° - 101°	W	259° - 281°
ESE	102° - 123°	WNW	282° - 303°
SE	124° - 146°	NW	304° - 326°
SSE	147° - 168°	NNW	327° - 348°

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Wind Speed

These symbols are affixed to the end of the wind direction indicator and point in the direction of lower pressure, i.e. to the right of the wind direction indicator in the Southern Hemisphere, and to the left in the Northern Hemisphere.

Knots	Knots	Knots
2	25	50
5	30	55
10	35	60
15	40	65
20	45	70

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