knmi

Ruby API to access Royal Netherlands Meteorological Institute daily climate data

Access climatological data as provided by the Royal Netherlands Meteorological Institute through the http get form. www.knmi.nl/climatology/daily_data/getdata_day.cgi

Please Note the disclaimer included in the header! # DEZE GEGEVENS MOGEN VRIJ WORDEN GEBRUIKT MITS DE VOLGENDE BRONVERMELDING WORDT GEGEVEN: # KONINKLIJK NEDERLANDS METEOROLOGISCH INSTITUUT (KNMI) # # THESE DATA CAN BE USED FREELY PROVIDED THAT THE FOLLOWING SOURCE IS ACKNOWLEDGED: # ROYAL NETHERLANDS METEOROLOGICAL INSTITUTE

Details about data here

www.knmi.nl/climatology/daily_data/scriptxs-en.html)

Station list here

www.knmi.nl/climatology/daily_data/scriptxs-en.html

data is parsed into a array of hashes with keys for each element

{ [ “STN” => 210, “YYYMMDD” => 20110427, “TG” => 25 ] }

Installation

gem install knmi

Dependancies

httparty >= 0.7.4

Data

Please note that the data must be converted from fixnum to float, I will include a method to take care of this in my next version.

YYYYMMDD = Date (YYYY=year MM=month DD=day) DDVEC = Vector mean wind direction in degrees (360=north, 90=east, 180=south, 270=west, 0=calm/variable) FHVEC = Vector mean windspeed (in 0.1 m/s) FG = Daily mean windspeed (in 0.1 m/s) FHX = Maximum hourly mean windspeed (in 0.1 m/s) FHXH = Hourly division in which FHX was measured FHN = Minimum hourly mean windspeed (in 0.1 m/s) FHNH = Hourly division in which FHN was measured FXX = Maximum wind gust (in 0.1 m/s) FXXH = Hourly division in which FXX was measured TG = Daily mean temperature in (0.1 degrees Celsius) TN = Minimum temperature (in 0.1 degrees Celsius) TNH = Hourly division in which TN was measured TX = Maximum temperature (in 0.1 degrees Celsius) TXH = Hourly division in which TX was measured T10N = Minimum temperature at 10 cm above surface (in 0.1 degrees Celsius) T10NH = 6-hourly division in which T10N was measured; 6=0-6 UT, 12=6-12 UT, 18=12-18 UT, 24=18-24 SQ = Sunshine duration (in 0.1 hour) calculated from global radiation (-1 for <0.05 hour) SP = Percentage of maximum potential sunshine duration Q = Global radiation (in J/cm2) DR = Precipitation duration (in 0.1 hour) RH = Daily precipitation amount (in 0.1 mm) (-1 for <0.05 mm) RHX = Maximum hourly precipitation amount (in 0.1 mm) (-1 for <0.05 mm) RHXH = Hourly division in which RHX was measured PG = Daily mean sea level pressure (in 0.1 hPa) calculated from 24 hourly values PX = Maximum hourly sea level pressure (in 0.1 hPa) PXH = Hourly division in which PX was measured PN = Minimum hourly sea level pressure (in 0.1 hPa) PNH = Hourly division in which PN was measured VVN = Minimum visibility; 0: <100 m, 1:100-200 m, 2:200-300 m,…, 49:4900-5000 m, 50:5-6 km, 56:6-7 km, 57:7-8 km,…, 79:29-30 km, 80:30-35 km, 81:35-40 km,…, 89: >70 k VVNH = Hourly division in which VVN was measured VVX = Maximum visibility; 0: <100 m, 1:100-200 m, 2:200-300 m,…, 49:4900-5000 m, 50:5-6 km, 56:6-7 km, 57:7-8 km,…, 79:29-30 km, 80:30-35 km, 81:35-40 km,…, 89: >70 k VVXH = Hourly division in which VVX was measured NG = Mean daily cloud cover (in octants, 9=sky invisible) UG = Daily mean relative atmospheric humidity (in percents) UX = Maximum relative atmospheric humidity (in percents) UXH = Hourly division in which UX was measured UN = Minimum relative atmospheric humidity (in percents) UNH = Hourly division in which UN was measured EV24 = Potential evapotranspiration (Makkink) (in 0.1 mm

List of Recorded Parameters and group name

When entering parameters in method call use groupname for collection of variables of use individual parameter names # Name - GroupName => [“Parameter”] * Wind - “WIND” => [“DDVEC”, “FG”, “FHX”, “FHX”, “FX”] * Temperature - “TEMP” => [“TG”, “TN”, “TX”, “T10N”] * Sunshine and global radiation - “SUNR” => [“SQ”, “SP”, “Q”] * Precipitation - “PRCP” => [“DR”, “RH”, “EV24”] * Sea-Level Pressure - “PRES” => [“PG”, “PGX”, “PGN”] * Visibility and Cloud Cover - “VICL” => [“VVN”, “VVX”, “NG”] * Humidity - “MSTR” => [“VVN”, “VVX”, “NG”] * “ALL” => [“DDVEC”, “FHVEC”, “FG”, “FHX”,

"FHXH", "FHN", "FHNH", "FXX", "FXXH", "TG", "TN", 
"TNH", "TX", "TXH", "T10N", "T10NH", "SQ", "SP", 
"Q", "DR", "RH", "RHX", "RHXH", "EV24", "PG", "PX", 
"PXH", "PN", "PNH", "VVN", "VVNH", "VVX", "VVXH", 
"NG", "UG", "UX", "UXH", "UN", "UNH"]

List of Method Parameters

station_number = number or array of numbers eg 210 or [210, 225]
vars = optional parameters to select measure parameters of interest if not defined all recorded parameters will be returned
response = KNMI.get_station(station_number, vars) this will return all daily values from the begining of the month to current
start = date in the form YYYYMMDD
end = date in the form YYYYMMDD

Method calls

response = KNMI.get_station(station_number, vars) this will return all daily values from the begining of the month to current for selected vars

response = KNMI.get_station_start_to_current(station_number, start, vars) this will return all daily values from defined start date to current

response = KNMI.get_station_range(station_number, start, end, vars) this will return all daily values from defined start date to defined end date

response = KNMI.get_station_seasonal(station_number, start, end, vars) this will return all daily values from seasonally defined start date to defined end date eg start = 19800123, end = 19840427 will return data between January 23 and April 27th for 1980 to 1984

KNMI.to_csv(“path/to/filename”, response) convenience function for writing response array to a csv