dwd-weather

Python client to access DWD weather data (Germany)

Install

pip install dwdweather

Quick reference (Python module)

from dwdweather import DwdWeather
from datetime import datetime

# create client
dw = DwdWeather()

# Find closest station to position
closest = dw.nearest_station(lon=7, lat=51)

# The hour you're interested in.
# The example is 2014-03-22 12:00 (UTC).
query_hour = datetime(2014, 3, 22, 12)

result = dw.query(station_id=closest["station_id"], hour=query_hour)
print result

DwdWeather.query() returns a dict with the following keys:

• station_id: Station identifier, as int.
• datetime: The hour as int, e.g. 2013011212.
• precipitation_fallen: Whether or not there has been precipitation within the hour, as int. 0 for no, 1 for yes.
• precipitation_form: TODO
• precipitation_height: Height of hourly precipitation in mm, as float.
• precipitation_quality_level: Data quality level, as int.
• soiltemp_1_depth: first soil temperature measurement, depth in meters, as float.
• soiltemp_1_temperature: first soil temperature measurement, temperature in degrees centigrade, as float.
• soiltemp_2_depth: second soil temperature measurement, depth in meters, as float.
• soiltemp_2_temperature: second soil temperature measurement, temperature in degrees centigrade, as float.
• soiltemp_3_depth: third soil temperature measurement, depth in meters, as float.
• soiltemp_3_temperature: third soil temperature measurement, temperature in degrees centigrade, as float.
• soiltemp_4_depth: fourth soil temperature measurement, depth in meters, as float.
• soiltemp_4_temperature: fourth soil temperature measurement, temperature in degrees centigrade, as float.
• soiltemp_5_depth: fifth soil temperature measurement, depth in meters, as float.
• soiltemp_5_temperature: fifth soil temperature measurement, temperature in degrees centigrade, as float.
• soiltemp_quality_level: soil temperature quality level, as int.
• solar_quality_level: quality level of solar data, as int.
• solar_duration: sunshine duration in minutes, as int.
• solar_sky: TODO
• solar_global: TODO
• solar_atmosphere: TODO
• solar_zenith: TODO
• sun_duration: Duration of sunshine per hour in minutes, as float.
• sun_quality_level: quality level of sunshine data, as int.
• sun_structure_version: version number, as int.
• temphum_humidity: relative air humidity in percent, as float.
• temphum_quality_level: data quality level of air temperature and humidity data, as int.
• temphum_structure_version: version number, as int.
• temphum_temperature: air temperature in degrees centigrade, as float.
• wind_direction: wind direction in degrees, as int (0 - 360).
• wind_quality_level: wind data quality level, as int.
• wind_speed: wind speed in meters per second, as float.
• wind_structure_version: version number, as int.

Command line utility:

Get closest station (first argument is longitude, second is latitude):

$ dwdweather station 7.0 51.0

Get all stations:

$ dwdweather stations

Export stations as CSV:

$ dwdweather stations -t csv -f stations.csv

Export stations as GeoJSON:

$ dwdweather stations -t geojson -f stations.geojson

Get weather at station for certain hour (UTC):

$ dwdweather weather 2667 2014060122

Some notes

• Data is cached in a local sqlite3 database for fast queries.
• The Stations cache is filled upon first request to DwdWeather.stations() or DwdWeather.nearest_station()
• The Stations cache will not be refreshed automatically. Use DwdWeather.import_stations() to do this.
• The Measures cache is filled upon first access to measures using DwdWeather.query() and updated whenever a query cannot be fullfilled from the cache.
• The cache by default resides in ~/.dwd-weather directory. This can be influenced using the cachepath argument of DwdWeather().
• The amount of data can be ~60 MB per station for full historic extend and this will of course grow in the future.
• If weather data is queried and the query can't be fullfilled from the cache, data is loaded from the server at every query. Even if the data has been updated a second before. If the server doesn't have data for the requested time (e.g. since it's not yet available), this causes superfluous network traffic and wait time. Certainly space for improvement here.

License (Code)

Licensed under the MTI license. See file LICENSE for details.

Data license

The DWD has information about their re-use policy in German and English.

Status

This piece of software is in a very early stage. No test cases yet. Only used unter Python 2.7.5. Use at your own risk.

Changelog

• Version 0.7:
  • Adapted to match modified Schema for sun data
• Version 0.6:
  • Adapted to match modified Schema for wind and air temperature data
• Version 0.5:
  • Fixed a problem where verbosity was not set
• Version 0.4:
  • Uses different DWD FTP server, no longer requires FTP user authentication
  • Provides access to more data ("solar")
  • Reading of station data much faster due to use of specific files from DWD
  • Additional fixes
• Version 0.2:
  • Added command line client functions
• Version 0.1:
  • Initial version