Present weather codes produced by the CS125

SYNOP and generic SYNOP code definitions provides the 57 SYNOP and generic SYNOP codes that can be output by the sensor. METAR code definitions1 provides METAR codes from WMO table 4678. NWS code definitions provides the NWS codes that may be produced by the CS125 in a custom message.

SYNOP and generic SYNOP code definitions
Weather type	4680 code
No significant weather observed	0
Haze, smoke, or dust in suspension in the air; visibility ≥ 1 km¹	4
Haze, smoke, or dust in suspension in the air; visibility < 1 km¹	5
Mist	10
Fog (in the preceding hour)	20
Precipitation (in the preceding hour)	21
Drizzle (not freezing) or snow grains (in the preceding hour)	22
Rain (not freezing), (in the preceding hour)	23
Snow (in the preceding hour)	24
Freezing rain or freezing drizzle (in the preceding hour)	25
FOG	30
Fog or ice fog in patches	31
Fog or ice fog in patches that has become thinner during the past hour	32
Fog or ice fog in patches with little change during the past hour	33
Fog or ice fog in patches has begun or become thicker during the past hour	34
Fog depositing rime	35
PRECIPITATION	40
Precipitation: slight or moderate	41
Precipitation: heavy	42
Solid precipitation: slight or moderate²	43
Freezing precipitation: slight or moderate²	44
Freezing precipitation: heavy²	45
DRIZZLE²	50
Drizzle: not freezing, slight	51
Drizzle: not freezing, moderate	52
Drizzle: not freezing, heavy	53
Drizzle: freezing, slight	54
Drizzle: freezing, moderate	55
Drizzle: freezing, heavy	56
Drizzle and rain: slight	57
Drizzle and rain: moderate or heavy	58
RAIN²	60
Rain: slight	61
Rain: moderate	62
Rain: heavy	63
Rain, freezing: slight	64
Rain, freezing: moderate	65
Rain, freezing: heavy	66
Rain (or drizzle) and snow: slight	67
Rain (or drizzle) and snow: moderate or heavy	68
SNOW²	70
Snow: slight (snow includes graupel)	71
Snow: moderate (snow includes graupel)	72
Snow: heavy (snow includes graupel)	73
Ice pellets: slight	74
Ice pellets: moderate	75
Ice pellets: heavy	76
Snow grains	77
SHOWER(S) OR INTERMITTENT PRECIPITATION	80
Rain shower(s) or intermittent rain: slight	81
Rain shower(s) or intermittent rain: moderate	82
Rain shower(s) or intermittent rain: heavy	83
Rain shower(s) or intermittent rain: violent	84
Snow shower(s) or intermittent snow: slight	85
Snow shower(s) or intermittent snow: moderate	86
Snow shower(s) or intermittent snow: heavy	87
Hail	89
¹Only reported if a HygroVue sensor is connected to provide relative humidity; otherwise, it will default to mist (10) or fog (20, 30, 31, 32, 33, 34, or 35). ²Only reported in the generic SYNOP messages.

METAR code definitions¹
Weather type	METAR code
Unidentified precipitation	UP
Haze²	HZ
Mist³	BR
Fog³	FG
Drizzle^{3, 4}	DZ
Rain^{3, 4}	RA
Snow grains	SG
Snow⁴	SN
Ice pellets⁴	PL
Hail	SMGR
No significant weather	NSW
¹ Combinations of the codes can be reported. (for example, RASN for rain and snow). ² HZ is only be reported if a HygroVue sensor is connected to the CS125 to provide relative humidity information. ³ FZ (freezing) may be added as a descriptor in front of BR, FG, DZ, and RA (for example, FZBR for freezing mist). ⁴ Intensity qualifiers (– for light and + for heavy) may be added in front of DZ, RA, SN, and PL (for example –RA for light rain or +SN for heavy snow).

NWS code definitions
Weather type	NWS code¹
Drizzle²	L
Rain²	R
Snow	S
Snow grains	SG
¹Intensity qualifiers (– for light and + for heavy) may be added after the NWS code (for example –R for light rain or +S for heavy snow). ²FZ (freezing) may be added as a descriptor in front of L and R (for example, FZL for freezing drizzle).