weather_exporter

A Multi-provider Prometheus Exporter for Weather Metrics

Motivation

There are a number of existing exporters for Current Weather Conditions, but none that I could find which supported multiple providers, reported numerous conditions as metrics, and had containers built for ARM platforms like Raspberry Pi.

Metrics Reported

Metric	Description	Notes
weather_description	Human-readable description of the current conditions
weather_temperature	The temperature at ground level, in Celsius
weather_feelslike	The apparent (feels like) temperature at ground level
weather_humidity	The current relative humidity percentage
weather_pressure_msl	The mean atmospheric pressure at sea level (MSL), in hPa
weather_pressure_surface	The atmospheric pressure at the ground/surface level, in hPa
weather_cloud_pct	The cloud cover percentage
weather_rain	The current hourly rainfall rate, in mm
weather_snow	The current hourly snowfall rate, in mm
weather_visibility	The visibility, in meters
weather_uv_index	The ultraviolet index
weather_wind_dir	The wind direction, in degrees
weather_wind_gust	The maximum wind gust speed, in meters/second
weather_wind_speed	The wind speed, in meters/second
weather_aq_index	The air quality index
weather_co_conc	The carbon monoxide (CO) concentration, in μg/m^3
weather_nh3_conc	The ammonia (NH3) concentration, in μg/m^3
weather_no2_conc	The nitrogen dioxide (NO2) concentration, in μg/m^3
weather_no_conc	The nitrogen monoxide (NO) concentration, in μg/m^3
weather_o3_conc	The ozone (O3) concentration, in μg/m^3
weather_pm10_conc	The coarse particulate (<10μm) concentration, in μg/m^3
weather_pm2p5_conc	The fine particulate (<2.5μm) concentration, in μg/m^3
weather_so2_conc	The sulfur dioxide (SO2) concentration, in μg/m^3

Configuration

Because it was designed to run in a container, configuration of the weather exporter is performed via environment variables. Some variables are generic and apply to all providers, while others are specific to individual providers.

Variable	Provider	Notes	Default
WEX_BIND_ADDR	All	The address and port that the application binds to	":6465"
WEX_TTL	All	To prevent querying remote APIs more frequently than necessary, or exceeding rate limits on API keys, a client side HTTP cache can be enabled. This sets the TTL on the cache	"10m"
WEX_OMET_COORDS	OpenMeteo	Lat/lon pairs for locations to query weather from OpenMeteo, in the format of "lat,lon;lat,lon"	""
WEX_OW_COORDS	OpenWeatherMap	Lat/lon pairs for locations to query weather from OpenWeatherMap, in the format of "lat,lon;lat, lon"	""
WEX_OW_APIKEY	OpenWeatherMap	The OpenWeatherMap API Key	""
WEX_TIO_COORDS	Tomorrow.io	Lat/lon pairs for locations to query weather from Tomorrow.io	""
WEX_TIO_APIKEY	Tomorrow.io	The Tomorrow.io API Key	""
WEX_WAPI_COORDS	WeatherAPI	Lat/lon pairs for locations to query weather from WeatherAPI.com	""
WEX_WAPI_APIKEY	WeatherAPI	The WeatherAPI API Key	""

Provider Notes

Though an attempt has been made to normalize the information reported from each provider, there are some discrepancies between them, which have been captured below.

OpenWeatherMap

When configured using the WEX_OW_COORDS environment variable, the weather_exporter will use the OpenWeatherMap.org API to retrieve current weather conditions and make them available to Prometheus. This uses the v2.5 API, which (while out-of-date) does not require a credit card to sign up.

Tomorrow.io

The Tomorrow.io API provides access to current conditions for an area using a free API key, but a premium subscription is required for access to the Air Quality API, so this is not currently implemented.

Open-Meteo

The Open-Meteo API provides for up to 10,000 requests per day without an API Key required, making it a good free and open source solution. By default, this provider pulls from multiple weather services, including the NOAA GFS, the ICON, and the European ECMWF.

WeatherAPI

This configuration uses the WeatherAPI.com Realtime API to query current conditions for an area, with 15-minute update intervals.

Examples

Docker Compose

The following example shows a docker-compose.yml file configured to use OpenWeatherMap to report weather metrics in New York City

version: "3.8"
services:
  weather_exporter:
    image: gca3020/weather_exporter:latest
    container_name: weather_exporter
    restart: unless-stopped
    ports:
    - '9265:9265'
    environment:
    - WEX_BIND_ADDR=":9265"
    - WEX_TTL="10m"
    - WEX_OW_APIKEY=super-secret-api-key
    - WEX_OW_COORDS="40.75,-73.99"

Prometheus Configuration

scrape_configs:
- job_name: "weather"
  scrape_interval: "10m"
  scrape_timeout: "1m"
  static_configs:
  - targets:
    - "weather_exporter:9265"