Present Weather Codes, WMO SYNOP 4680, WMO 4678

Present weather sensors report the weather type (clear, fog, snow, ++) with a numeric or a text value. The table below document the relevant values and their relationship. The "Used" column indicates if the value is (typically) used by present weather sensors.

Please refer to WMO for latest version of these tables.

Used	SYNOP	4678	Weather Type

Used	SYNOP	4678	Weather Type
Yes	00		Clear, No significant weather observed
No	01		Clouds generally dissolving or becoming less developed during the past hour
No	02		State of sky on the whole unchanged during the past hour
No	03		Clouds generally forming or developing during the past hour
Yes	04	HZ	Haze or smoke, or dust in suspension in the air, visibility equal to, or greater than, 1 km
Yes	05	DU	Haze or smoke, or dust in suspension in the air, visibility less than 1 km
No	06–09		Reserved
Yes	10	BR	Mist
No	11		Diamond dust
No	12		Distant lightning
No	13-17		Reserved
No	18		Squalls
No	19		Reserved
			Code figures 20–26 are used to report precipitation, fog (or ice fog) or thunderstorm at the station during the preceding hour but not at the time of observation.
Yes	20		Fog
Yes	21	REUP	PRECIPITATION
Yes	22	REDZ	Drizzle (not freezing) or snow grains
Yes	23	RERA	Rain (not freezing)
Yes	24	RESN	Snow
Yes	25	REFZRA REFZDZ	Freezing rain or freezing drizzle
No	26		Thunderstorm (with or without precipitation)
No	27		BLOWING OR DRIFTING SNOW OR SAND
No	28		Blowing or drifting snow or sand, visibility equal to, or greater than, 1 km
No	29		Blowing or drifting snow or sand, visibility less than 1 km
			The following code figures are used if precipitation or fog is observed at the time of observation
Yes	30	FG	FOG
Yes	31	BCFG	Fog or ice fog in patches
Yes	32	FG	Fog or ice fog, has become thinner during the past hour
Yes	33	FG	Fog or ice fog, no appreciable change during the past hour
Yes	34	FG	Fog or ice fog, has begun or become thicker during the past hour
No	35	FZFG	Fog, depositing rime
No	36-39		Reserved
Yes	40	UP	PRECIPITATION
Yes	41	-UP	Precipitation, slight or moderate
Yes	42	+UP	Precipitation, heavy
No	43		Liquid precipitation, slight or moderate
No	44		Liquid precipitation, heavy
No	45		Solid precipitation, slight or moderate
No	46		Solid precipitation, heavy
No	47		Freezing precipitation, slight or moderate
No	48		Freezing precipitation, heavy
No	49		Reserved
Yes	50	DZ	DRIZZLE
Yes	51	−DZ	Drizzle, not freezing, slight
Yes	52	DZ	Drizzle, not freezing, moderate
Yes	53	+DZ	Drizzle, not freezing, heavy
Yes	54	−FZDZ	Drizzle, freezing, slight
Yes	55	FZDZ	Drizzle, freezing, moderate
Yes	56	+FZDZ	Drizzle, freezing, heavy
No	57	−DZRA	Drizzle and rain, slight
No	58	DZRA +DZRA	Drizzle and rain, moderate or heavy
No	59		Reserved
Yes	60	RA	RAIN
Yes	61	−RA	Rain, not freezing, slight
Yes	62	RA	Rain, not freezing, moderate
Yes	63	+RA	Rain, not freezing, heavy
Yes	64	−FZRA	Rain, freezing, slight
Yes	65	FZRA	Rain, freezing, moderate
Yes	66	+FZRA	Rain, freezing, heavy
Yes	67	−RASN	Rain (or drizzle) and snow, slight
Yes	68	RASN +RASN	Rain (or drizzle) and snow, moderate or heavy
No	69		Reserved
Yes	70	SN	SNOW
Yes	71	−SN	Snow, slight
Yes	72	SN	Snow, moderate
Yes	73	+SN	Snow, heavy
Yes	74	−PL	Ice pellets, slight
Yes	75	PL	Ice pellets, moderate
Yes	76	+PL	Ice pellets, heavy
No	77	-SG SG +SG	Snow grains
No	78		Ice crystals
No	79		Reserved
Yes	80	SHUP	SHOWER(S) or INTERMITTENT PRECIPITATION
Yes	81	−SHRA	Rain shower(s) or intermittent rain, slight
Yes	82	SHRA	Rain shower(s) or intermittent rain, moderate
Yes	83	+SHRA	Rain shower(s) or intermittent rain, heavy
Yes	84	+SHRA	Rain shower(s) or intermittent rain, violent