RMI Documentation for dataset 'Synoptic observations'



PRECIP_QUANTITY = amount of precipitation in mm.

PRECIP_RANGE = period over which PRECIP_QUANTITY was measured.

  • 1 = past 6h
  • 2 = past 12h
  • 4 = past 24h

Value at 0600UT: sum of precipitation between 1750-0550UT

Value at 1200UT: sum of precipitation between 0550-1150UT

Value at 1800UT: sum of precipitation between 0550-1750UT

Value at 0000UT: sum of precipitation between 1750-2350UT


TEMP = air temperature at 1.5m in °C (hourly)
1 value every hour: average measured between (T – 11 min) and (T – 10 min)

TEMP_MIN = minimum temperature between 18h UT (previous day) and 6h UT (current day) in °C (1 value per day)
min between 1750UT (previous day) and 0550UT (current day).

TEMP_MAX = maximum temperature between 6h UT and 18h UT in °C (1 value per day)
max between 0550 and 1750UT

TEMP_GRASS_MIN = minimum temperature at the soil (°C) at 6UT and 9UT
Temperature measured between 1750 to 0550 for 0600 UT and between 2150 to 0850 for 0900UT


WIND_SPEED = average wind speed of the last 10 minutes at 10m altitude (hourly)
measured between (T – 20 min) and (T – 10 min)

WIND_SPEED_UNIT = unit of the wind speed
0,1 = m/s or 3,4 = knots

WIND_DIRECTION = wind direction in degrees (hourly)
average wind direction between (T – 20 min) and (T – 10 min)

Degrees Text Degrees Text
350/360/10 N 200/210 SSW
20/30 NNE 220/230 SW
40/50 NE 240/250 WSW
60/70 ENE 260/270/280 W
80/90/100 E 290/300 WNW
110/120 ESE 310/320 NW
130/140 SE 330/340 NNW
150/160 SSE 999 VARIABLE
170/180/190 S - or 0 NO WIND

WIND_PEAK_SPEED = maximum wind speed (m/s)

  • Value at 0300UT: maximum between 2350-0250UT
  • Value at 0600UT: maximum between 2350-0550UT
  • Value at 0900UT: maximum between 0550-0850UT
  • Value at 1200UT: maximum between 0550-1150UT
  • Value at 1500UT: maximum between 1150-1450UT
  • Value at 1800UT: maximum between 1150-1750UT
  • Value at 2100UT: maximum between 1750-2050UT
  • Value at 0000UT: maximum between 1750-2350UT

Relative humidity

HUMIDITY_RELATIVE = relative humidity of the air in % (hourly)
average RH measured/calculated between (T – 11 min) and (T – 10 min)

Weather type

WEATHER_CURRENT = description of the current weather type (hourly)

CodeCurrent weather
0clear skies
1clouds dissolving
2state of sky unchanged
3clouds developing
4visibility reduced by smoke
6widespread dust in suspension not raised by wind
7dust or sand raised by wind
8well developed dust or sand whirls
9dust or sand storm within sight but not at station
11patches of shallow fog
12continuous shallow fog
13lightning visible, no thunder heard
14precipitation within sight but not hitting ground
15distant precipitation but not falling at station
16nearby precipitation but not falling at station
17thunderstorm but no precipitation falling at station
18squalls within sight but no precipitation falling at station
19funnel clouds within sight
20drizzle (not freezing) or snow grains
23rain and snow
24freezing rain
25rain showers
26snow showers
27hail showers
30slight to moderate duststorm, decreasing in intensity
31slight to moderate duststorm, no change
32slight to moderate duststorm, increasing in intensity
33severe duststorm, decreasing in intensity
34severe duststorm, no change
35severe duststorm, increasing in intensity
36slight to moderate drifting snow, below eye level
37heavy drifting snow, below eye level
38slight to moderate drifting snow, above eye level
39heavy drifting snow, above eye level
40Fog at a distance
41patches of fog
42fog, sky visible, thinning
43fog, sky not visible, thinning
44fog, sky visible, no change
45fog, sky not visible, no change
46fog, sky visible, becoming thicker
47fog, sky not visible, becoming thicker
48fog, depositing rime, sky visible
49fog, depositing rime, sky not visible
50intermittent light drizzle
51continuous light drizzle
52intermittent moderate drizzle
53continuous moderate drizzle
54intermittent heavy drizzle
55continuous heavy drizzle
56light freezing drizzle
57moderate to heavy freezing drizzle
58light drizzle and rain
59moderate to heavy drizzle and rain
60intermittent light rain
61continuous light rain
62intermittent moderate rain
63continuous moderate rain
64intermittent heavy rain
65continuous heavy rain
66light freezing rain
67moderate to heavy freezing rain
68light rain and snow
69moderate to heavy rain and snow
70intermittent light snow
71continuous light snow
72intermittent moderate snow
73continuous moderate snow
74intermittent heavy snow
75continuous heavy snow
76diamond dust
77snow grains
78snow crystals
79ice pellets
80light rain showers
81moderate to heavy rain showers
82violent rain showers
83light rain and snow showers
84moderate to heavy rain and snow showers
85light snow showers
86moderate to heavy snow showers
87light snow/ice pellet showers
88moderate to heavy snow/ice pellet showers
89light hail showers
90moderate to heavy hail showers
91thunderstorm in past hour, currently only light rain
92thunderstorm in past hour, currently only moderate to heavy rain
93thunderstorm in past hour, currently only light snow or rain/snow mix
94thunderstorm in past hour, currently only moderate to heavy snow or rain/snow mix
95light to moderate thunderstorm
96light to moderate thunderstorm with hail
97heavy thunderstorm
98heavy thunderstorm with duststorm
99heavy thunderstorm with hail
100No significant weather observed
101Clouds generally dissolving or becoming less developed during the past hour
102State of sky on the whole unchanged during the past hour
103Clouds generally forming or developing during the past hour
104Haze or smoke, or dust in suspension in the air, visibility equal to, or greater than, 1 km
105Haze or smoke, or dust in suspension in the air, visibility less than 1 km
111Diamond dust
112Distant lightning
122Drizzle (not freezing) or snow grains
123Rain (not freezing)
125Freezing drizzle or freezing rain
126Thunderstorm (with or without precipitation)
127Blowing or drifting snow or sand
128Blowing or drifting snow or sand, visibility equal to, or greater than, 1 km
129Blowing or drifting snow or sand, visibility less than 1 km
131Fog or ice fog in patches
132Fog or ice fog, has become thinner during the past hour
133Fog or ice fog, no appreciable change during the past hour
134Fog or ice fog, has begun or become thicker during the past hour
135Fog, depositing rime
141Precipitation, slight or moderate
142Precipitation, heavy
143Liquid precipitation, slight or moderate
144Liquid precipitation, heavy
145Solid precipitation, slight or moderate
146Solid precipitation, heavy
147Freezing precipitation, slight or moderate
148Freezing precipitation, heavy
151Drizzle, not freezing, slight
152Drizzle, not freezing, moderate
153Drizzle, not freezing, heavy
154Drizzle, freezing, slight
155Drizzle, freezing, moderate
156Drizzle, freezing, heavy
157Drizzle and rain, slight
158Drizzle and rain, moderate or heavy
161Rain, not freezing, slight
162Rain, not freezing, moderate
163Rain, not freezing, heavy
164Rain, freezing, slight
165Rain, freezing, moderate
166Rain, freezing, heavy
167Rain (or drizzle) and snow, slight
168Rain (or drizzle) and snow, moderate or heavy
171Snow, slight
172Snow, moderate
173Snow, heavy
174Ice pellets, slight
175Ice pellets, moderate
176Ice pellets, heavy
177Snow grains
178Ice crystals
180Shower(s) or intermittent precipitation
181Rain shower(s) or intermittent rain, slight
182Rain shower(s) or intermittent rain, moderate
183Rain shower(s) or intermittent rain, heavy
184Rain shower(s) or intermittent rain, violent
185Snow shower(s) or intermittent snow, slight
186Snow shower(s) or intermittent snow, moderate
187Snow shower(s) or intermittent snow, heavy
191Thunderstorm, slight or moderate, with no precipitation
192Thunderstorm, slight or moderate, with rain showers and/or snow showers
193Thunderstorm, slight or moderate, with hail
194Thunderstorm, heavy, with no precipitation
195Thunderstorm, heavy, with rain showers and/or snow showers
196Thunderstorm, heavy, with hail
204Volcanic ash suspended in the air aloft
206Thick dust haze, visibility less than 1 km
207Blowing spray at the station
208Drifting dust (sand)
209Wall of dust or sand in distance (like haboob)
210Snow haze
213Lightning, cloud to surface
217Dry thunderstorm
219Tornado cloud (destructive) at or within sight of the station during preceding hour or at the time of observation
220Deposition of volcanic ash
221Deposition of dust or sand
222Deposition of dew
223Deposition of wet snow
224Deposition of soft rime
225Deposition of hard rime
226Deposition of hoar frost
227Deposition of glaze
228Deposition of ice crust (ice slick)
230Duststorm or sandstorm with temperature below 0° C
239Blowing snow, impossible to determine whether snow is falling or not
241Fog on sea
242Fog in valleys
243Arctic or Antarctic sea smoke
244Steam fog (sea, lake or river)
245Steam log (land)
246Fog over ice or snow cover
247Dense fog, visibility 60–90 m
248Dense fog, visibility 30–60 m
249Dense fog, visibility less than 30 m
250Drizzle, rate of fall less than 0.10 mm h-1
251Drizzle, rate of fall 0.10–0.19 mm h–1
252Drizzle, rate of fall 0.20–0.39 mm h–1
253Drizzle, rate of fall 0.40–0.79 mm h-1
254Drizzle, rate of fall 0.80–1.59 mm h–1
255Drizzle, rate of fall 1.60–3.19 mm h–1
256Drizzle, rate of fall 3.20–6.39 mm h–1
257Drizzle, rate of fall 6.4 mm h-1 or more
259Drizzle and snow
260Rain, rate of fall less than 1.0 mm h-1
261Rain, rate of fall 1.0–1.9 mm h-1
262Rain, rate of fall 2.0–3.9 mm h–1
263Rain, rate of fall 4.0–7.9 mm h–1
264Rain, rate of fall 8.0–15.9 mm h–1
265Rain, rate of fall 16.0–31.9 mm h–1
266Rain, rate of fall 32.0–63.9 mm h–1
267Rain, rate of fall 64.0 mm h–1 or more
270Snow, rate of fall less than 1.0 cm h-1
271Snow, rate of fall 1.0–1.9 cm h–1
272Snow, rate of fall 2.0–3.9 cm h–1
273Snow, rate of fall 4.0–7.9 cm h–1
274Snow, rate of fall 8.0–15.9 cm h–1
275Snow, rate of fall 16.0–31.9 cm h–1
276Snow, rate of fall 32.0–63.9 cm h–1
277Snow, rate of fall 64.0 cm h–1 or more
278Snow or ice crystal precipitation from a clear sky
279Wet snow, freezing on contact
280Precipitation of rain
281Precipitation of rain, freezing
282Precipitation of rain and snow mixed
283Precipitation of snow
284Precipitation of snow pellets or small hall
285Precipitation of snow pellets or small hail, with rain
286Precipitation of snow pellets or small hail, with rain and snow mixed
287Precipitation of snow pellets or small hail, with snow
288Precipitation of hail
289Precipitation of hail, with rain
290Precipitation of hall, with rain and snow mixed
291Precipitation of hail, with snow
292Shower(s) or thunderstorm over sea
293Shower(s) or thunderstorm over mountains
508No significant phenomenon to report, present and past weather omitted
509No observation, data not available, present and past weather omitted
510Present and past weather missing, but expected
511Missing value


PRESSURE = air pressure at sea level (hPa) (hourly)
measured between (T – 11 min) and (T – 10 min)

PRESSURE_STATION_LEVEL = air pressure at station level (hPa) (hourly)
measured between (T – 11 min) and (T – 10 min)

Sunshine duration

SUN_DURATION_24HOURS = sunshine duration (period during which more than 120W/m² in solar radiation is measured) over the last 24h (in minutes) (1 value per day)
measured between (T – 24 h 10 min) and (T – 10 min)

Global radiation

SHORT_WAVE_FROM_SKY_24HOURS: Global solar radiation integrated over 24h (in J/m²)
Global radiation measured between between (T – 24 h 10 min) and (T – 10 min)

Total cloudiness

CLOUDINESS = part of the sky covered in clouds (in octas)

Synoptic hours (worldwise use)

+ relative humidity
+ pressure
Temp_min Temp_max Temp_grass Precip Wind speed
+ Wind direction
Wind peak speed Sunshine duration
+ global radiation
0000 UT 23:49-23:50 17:50-23:50 23:40-23:50 17:50-23:50 23:50-23:50
0100 UT 00:49-00:50 00:40-00:50
0200 UT 01:49-01:50 01:40-01:50
0300 UT 02:49-02:50 02:40-02:50 23:50-02:50
0400 UT 03:49-03:50 03:40-03:50
0500 UT 04:49-04:50 04:40-04:50
0600 UT 05:49-05:50 17:50-05:50 17:50-05:50 17:50-05:50 05:40-05:50 23:50-05:50
0700 UT 06:49-06:49 06:40-06:50
0800 UT 07:49-07:50 07:40-07:50
0900 UT 08:49-08:50 21:50-08:50 08:40-08:50 05:50-08:50
1000 UT 09:49-09:50 09:40-09:50
1100 UT 10:49-10:50 10:40-10:50
1200 UT 11:49-11:50 05:50-11:50 11:40-11:50 05:50-11:50
1300 UT 12:49-12:50 12:40-12-50
1400 UT 13:49-13:50 13:40-13:50
1500 UT 14:49-14:50 14:40-14:50 11:50-14:50
1600 UT 15:49-15:50 15:40-15:50
1700 UT 16:49-16:49 16:40-16:50
1800 UT 17:49-17:50 05:50-17:50 05:50-17:50 17:40-17:50 11:50-17:50
1900 UT 18:49-18:50 18:40-18:50
2000 UT 19:49-19:50 19:40-19:50
2100 UT 20:49-20:50 20:40-20:50 17:50-20:50
2200 UT 21:49-21:50 21:40-21:50
2300 UT 22:49-22:50 22:40-22:50
Last update : 24/09/2021 16:11