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Documentation Actuele10mindataKNMIstations

KNMI collects observations from the automatic weather stations situated in the Netherlands and BES islands on locations such as aerodromes and North Sea platforms. In addition, wind data from KNMI wind poles are included. The weather stations report every 10 minutes meteorological parameters such as temperature, relative humidity, wind, air pressure, visibility, precipitation and cloud cover. The number of parameters differs per station. The file for the past 10-minutes is available a few minutes later. It is possible that a station's observations may not be immediately available. Files are updated with missing data up to 4 hours later.

Purpose

This actual 10 minute dataset is intended as a near-real-time dataset, allowing KNMI to make the observations available as quickly as possible. Other datasets aim for maximum completeness, such as the data provided by daggegevens.knmi.nl. Some stations have multiple sensors of the same type, which means that different sensors may be responsible for the same variables. As a rule, both sets of numbers can be considered representative and are calibrated and maintained. All sensors have been validated for climatology purposes.

Time

De times in the file are in UTC. For the file name, the dates imply the time period before that time. For example, KMDS__OPER_P___10M_OBS_L2_202301010900.nc has the time period 08:50-09:00 UTC. For the Netherlands, the time in winter is UTC+1, and for summer time UTC+2. There are a few variables that have a different time period. The variables rh10, t10, and td10 have their timestamp in the middle, with the time period of 08:55-09:05.

Stations

If you want to know more about which stations are used and where they are located, please go to the weather stations dataset on the Data Platform. For instance, wind masts and stations in the North Sea have been included in the Actuele10mindataKNMIstations. However, it is important to note that some of these monitoring stations may not yet be completely operational. The data are representative and valid for the measured weather conditions but have not yet been incorporated into the climatological validated datasets.

Note: Not all variables are measured at all stations.

Variables

Here is a list of all variables that are available at one or more stations, with their description and their units. You may find comments next to some variables, those are written out in the table below. 

MD = Marked Discontinuity. An abrupt change in wind speed and/or direction (10 knots, 30 degrees, minimum 2 minutes) within a 10-minute interval. After a MD, the values before the MD are no longer included in the 10-minute average. As per WMO and ICAO guidelines.

All variables present in Actuele10mindataKNMIstations
Variables Description Unit Comments
D1H Rainfall Duration in last Hour min
dd Wind Direction 10 Min Average with MD ° 1
dn Wind Direction Sensor 10 Min Minimum with MD ° 1
dr Precipitation Duration (Rain Gauge) 10 Min Sum sec
dsd Wind Direction 10 Min Std Dev with MD ° 1
dx Wind Direction Sensor 10 Min Maximum with MD ° 1
ff Wind Speed at 10m 10 Min Average with MD m/s 1
ffs Wind Speed Sensor 10 Min Average with MD m/s 1
fsd Wind Speed 10 Min Std Dev with MD m/s 1
fx Wind Gust at 10m Maximum last 10 Min Interval m/s 1
fxs Wind Gust Sensor Maximum last 10 Min Interval m/s 1
gff Wind Gust at 10m 10 Min Maximum with MD m/s 1
gffs Wind Gust Sensor 10 Min Maximum with MD m/s 1
h Cloud Base ft
h1 Cloud Base First Layer ft
h2 Cloud Base Second Layer ft
h3 Cloud Base Third Layer ft
hc Cloud Base Ceilometer Algorithm ft
hc1 Cloud Base Ceilometer First Layer ft
hc2 Cloud Base Ceilometer Second Layer ft
hc3 Cloud Base Ceilometer Third Layer ft
n Total cloud cover octa
n1 Cloud Amount First Layer octa
n2 Cloud Amount Second Layer octa
n3 Cloud Amount Third Layer octa
nc Total Cloud Cover Ceilometer octa
nc1 Cloud Amount Ceilometer First Layer octa
nc2 Cloud Amount Ceilometer Second Layer octa
nc3 Cloud Amount Ceilometer Third Layer octa
nhc Low and Middle Cloud Amount Ceilometer octa
p0 Air Pressure at Station Level 1 Min Average hPa
pg Precipitation Intensity (PWS) 10 Min Average mm/h 2
pp Air Pressure at Sea Level 1 Min Average hPa
pr Precipitation Duration (PWS) 10 Min Sum sec 2
ps Air Pressure at Sensor Level 1 Min Average hPa
pwc Corrected Precipitation Type 10 Min Maximum code KNMI Handboek waarnemingen 3
Q1H Global Radiation 1 Hour Sum J/cm²
Q24H Global Radiation 24 Hour Sum J/cm²
qg Global Solar Radiation 10 Min Average W/m²
qgn Global Solar Radiation 10 Min Minimum W/m²
qgx Global Solar Radiation 10 Min Maximum W/m²
qnh QNH 1 Min Average hPa
R12H Rainfall in last 12 Hours mm
R1H Rainfall in last Hour mm
R24H Rainfall in last 24 Hours mm
R6H Rainfall in last 6 Hours mm
rg Precipitation Intensity (Rain Gauge) 10 Min Average mm/h
rh Relative Humidity 1.5m 1 Min Average % 4
rh10 Relative Humidity 10 Min Average % 5
Sav1H Wind Speed Average last 1 Hour m/s 6
Sax1H Wind Speed Maximum last 1 Hour m/s 6
Sax3H Wind Speed Maximum last 3 Hours m/s 6
Sax6H Wind Speed Maximum last 6 Hours m/s 6
sq Squall Indicator code WMO table 4680 7
ss Sunshine Duration min
Sx1H Wind Gust Maximum last 1 Hour m/s 6
Sx3H Wind Gust Maximum last 3 Hours m/s 6
Sx6H Wind Gust Maximum last 6 Hours m/s 6
t10 Ambient Temperature 10 Min Average °C 8
ta Ambient Temperature 1.5m 10 Min Average °C 9
tb Wet Bulb Temperature 1.5m 10 Min Average °C
tb1 Soil Temperature -5cm 10 Min Average °C
Tb1n6 Soil Temperature -5cm Minimum last 6 Hours °C
Tb1x6 Soil Temperature -5cm Maximum last 6 Hours °C
tb2 Soil Temperature -10cm 10 Min Average °C
Tb2n6 Soil Temperature -10cm Minimum last 6 Hours °C
Tb2x6 Soil Temperature -10cm Maximum last 6 Hours °C
tb3 Soil Temperature -20cm 10 Min Average °C
tb4 Soil Temperature -50cm 10 Min Average °C
tb5 Soil Temperature -100cm 10 Min Average °C
td Dew Point Temperature 1.5m 1 Min Average °C 10
td10 Dew Point Temperature 10 Min Average °C 8
tg Grass Temperature 10cm 10 Min Average °C
tgn Grass Temperature 10cm 10 Min Minimum °C
Tgn12 Grass Temperature Minimum last 12 Hours °C
Tgn14 Grass Temperature Minimum last 14 Hours °C
Tgn6 Grass Temperature Minimum last 6 Hours °C
tn Ambient Temperature 1.5m 10 Min Minimum °C
Tn12 Air Temperature Minimum last 12 Hours °C
Tn14 Air Temperature Minimum last 14 Hours °C
Tn6 Air Temperature Minimum last 6 Hours °C
tsd SIAM Ambient Temperature 10 Min Average Std Dev °C
tx Ambient Temperature 1.5m 10 Min Maximum °C
Tx12 Air Temperature Maximum last 12 Hours °C
Tx24 Air Temperature Maximum last 24 Hours °C
Tx6 Air Temperature Maximum last 6 Hours °C
vv Horizontal Visibility 10 Min Average m 2
W10 Past Weather Indicator code WMO table 4680 11
W10-10 Past Weather Indicator for Previous 10 Min Interval code WMO table 4680 11
ww wawa Weather Code code WMO table 4680 11
ww-10 wawa Weather Code for Previous 10 Min Interval code WMO table 4680 11
za Background Luminance 10 Min Average cd/m² 2
zm Meteorological Optical Range 10 Min Average m 2

Comments for the variables

To better understand the observations, we now also introduce a table of observations. These are intended to provide insights and additional context to the observations. The comments are provided just as they appear in the metadata accompanying the files.

Comments for variables of Actuele10mindataKNMIstations
Number Comment
1 Note: For wind observations of stations 06209, 06285, 06308, 06312, 06313, 06315, 06316, 06324, 06331 the timestamp indicates the middle of the interval. At other locations the timestamp of the wind observations indicates the end of the interval. The wind sensors at stations 06225, 06229, 06242, 06258, 06260, 06310, 06330 and 06343 are located at different heights above the surrounding terrain than the standard 10m height, and the 10m wind speeds (ff, fx, gff) are copies of the wind speed measured at the height of the wind sensor (ffs, fxs, gffs respectively). The standard deviation of the wind speed (fsd) is not corrected for non-standard measurement height. At certain wind masts of Rijkswaterstaat (06209, 06225, 06229, 06285, 06308, 06312, 06313, 06315, 06316, 06324, 06331) and the platforms on the North Sea (06201, 06203, 06204, 06205, 06207, 06208, 06211, 06214, 06239, 06252, 06320, 06321, 06317), the wind speed is also measured at heights above mean sea level differing from 10m but the 10m wind speeds are estimates of the wind speed that would have been measured at 10m height, based on the sensor height measurements.
2 Note: The sensor is not installed at equal heights at all types of measurement sites: At 'AWS' sites the device is installed at 1.80m. At 'AWS/Aerodrome' and 'Mistpost' (note that this includes site Voorschoten (06215) which is 'AWS/Mistpost') the device is installed at 2.50m elevation. Exceptions are Berkhout AWS (06249), De Bilt AWS (06260) and Twenthe AWS (06290) where the sensor is installed at 2.50m.
3 KNMI: Handboek waarnemingen. 5.3 PW-code neerslagsoort. https://www.knmi.nl/kennis-en-datacentrum/publicatie/handboek-waarnemingen. Note: The sensor is not installed at equal heights at all types of measurement sites: At 'AWS' sites the device is installed at 1.80m. At 'AWS/Aerodrome' and 'Mistpost' (note that this includes site Voorschoten (06215) which is 'AWS/Mistpost') the device is installed at 2.50m elevation. Exceptions are Berkhout AWS (06249), De Bilt AWS (06260) and Twenthe AWS (06290) where the sensor is installed at 2.50m.
4 Note: For some locations only rh10 is provided
5 Note: For this variable the timestamp indicates the middle of the 10 Min interval
6 Note: For wind observations of stations 06209, 06285, 06308, 06312, 06313, 06315, 06316, 06324, 06331 the timestamp indicates the middle of the interval. At other locations the timestamp of the wind observations indicates the end of the interval. The wind sensors at stations 06225, 06229, 06242, 06258, 06260, 06310, 06330 and 06343 are located at different heights above the surrounding terrain than the standard 10m height, and the 10m wind speeds (ff, fx, gff) are copies of the wind speed measured at the height of the wind sensor (ffs, fxs, gffs respectively). The standard deviation of the wind speed (fsd) is not corrected for non-standard measurement height. At the wind masts of Rijkswaterstaat (mainly in the region Zeeland) and the platforms on the North Sea, the wind speed is also measured at heights above mean sea level differing from 10m but the 10m wind speeds are estimates of the wind speed that would have been measured at 10m height, based on the sensor height measurements.
7 WMO table 4680
8 Note: for this variable the timestamp indicates the middle of the 10 Min interval
9 Note: For some locations only t10 is provided
10 Note: For some locations only td10 is provided
11 WMO table 4680. Note: The sensor is not installed at equal heights at all types of measurement sites: At 'AWS' sites the device is installed at 1.80m. At 'AWS/Aerodrome' and 'Mistpost' (note that this includes site Voorschoten (06215) which is 'AWS/Mistpost') the device is installed at 2.50m elevation. Exceptions are Berkhout AWS (06249), De Bilt AWS (06260) and Twenthe AWS (06290) where the sensor is installed at 2.50m.