Detailed weather forecast from DWD (Deutscher Wetter Dienst)
This provides:
- a module to download German weather forecasts (10 days, 1 hour resolution) as pandas dataframe
- a module to generate a forecast plot
- a module to serve the forecast plot via web server for integration in home automation panels or similar
The plot shows detailed temperature forecasts and sunshine probabilites (yellow) and rain probabilities (blue).
Have a look at the jupyter notebook for an overview of the functionality.
Either use the reference list, column Stations-kennung is the station-id, provided by the Open Data project of DWD, or use the location API below.
Caveat: this reference list contains many weather stations that are no longer active, or do not provide forecast data. If you want to search manually, you will need to search for stations that are still active (look at Ende column which marks the last data transmission) and actually provide data.
The API call get_closest(lat,lon) does that automatically.
from dwd_forecast import DWD
d=DWD()
my_lat, my_lon=(48.15, 11.56)
nearest=d.get_closest(my_lat,my_lon)
print(nearest)
# ('10865', 'München-Stadt', Distance(1.9339969383980125))Station id is 10865, name of this station is München-Stadt, and the station is 1.93km from the given coordinates.
from dwd_forecast import DWD
d=DWD()
dw=d.station_forecast('10865') # station-id from above
dw.head() # dataframe with detailed forecast information (see https://opendata.dwd.de/weather/lib/MetElementDefinition.xml)from weather_plot import DwdForecastPlot
wp=DwdForecastPlot()
wp.plot("10865",image_file='weather.png') # station-id 10865 from above.from weather_server import WeatherServer
ws = WeatherServer(port=8089, keyfile=my_keyfile, certfile=my_certfile, threading=True) # creates thread that serves web requests, use `threading=False` with macOS.
while True:
time.sleep(1)If keyfile and certfile are ommited, the web server serves on http://localhost:8089/station/my-station-id, e.g. http://localhost:8089/station/10865. With cert- and keyfile given, https is used: https://hostname:8089/station/10865.
The server simply returns a PNG that can be embedded in other portals (e.g. Home Assistant)
python weather_server.py --port 8089 --certfile cert.pem --keyfile key.pem [-t] [--dpi 96]This starts a web server on port 8089, access for example for station 10865 with: http://localhost:8089/station/10865 (no certs given). With cert- and keyfile given, https is used: https://hostname:8089/station/10865
For auto-refresh, use the urls http[s]://hostname:8089/auto/10865. This loads a page that uses a simple script to automatically reload the updated forecasts (e.g. for use in panels that are permanently displayed.)
The file weather_server_sample.service can be used as a base for systemd installatins.
Options: -t: use threading (crashes on macOS, matplotlib can't work in threads!), --dpi 96 font resolution.
dwd_forecast:
pandas: Forecast results are given as pandasDataframesgeopy: [optional], needed to find nearest station via latitude/longitude search
weather_plot, additionally:
matplotlib,numpyfor plotting
weather_server, additionally:
flask,geventfor the web server part.pillow, to resize the resultant plot for Arudino billboards.
There's a special url ministation/<station-number> that delivers an RGB565 encoded bitmap of size 240x135 suitable for display on an Adafruit ESP32-S2-TFT. See ESP32 Billboard for example code.
Downloaded data is automatically cached to prevent unnecessary load on the DWD servers. Station-ID lists are cached for 1 day, and weather forecast data ist cached for 1 hour before the next download is initiated.
- 2023-06-22: macOS crashes when using matplotlib in a thread (web server used threading by default in previous versions.). Now uses default main thread for operation. Use option
-tto re-enable threading (for non macOS systems). - threading setDaemon parameter API renaming warning fixed.
- new parameter
--dpi, should be around 96, affects mainly relative font sizes