OpenWeatherMap
Devices & Services > OpenWeatherMap adds a location by latitude/longitude plus your own OpenWeatherMap API key (Current Weather + 5 Day/3 Hour Forecast APIs) - like every weather integration in Athena, the "device" is just a configured point on the map, not physical hardware.
What you get
Current conditions: temperature, feels-like, humidity, pressure, wind, cloud cover, precipitation, and condition. Forecast: daily min/max temperature, condition, and precipitation probability, for 5 days out - the location's own detail page also shows a small forecast strip with all 5 days at a glance. Every value is a read-only sensor, working with Dashboard cards, History, and Automations exactly like every other integration.
Polling
Polls every 10 minutes - comfortably inside the free tier's 60 calls/minute limit even with several locations configured.
OpenWeatherMap was the first of four weather integrations Athena added (alongside Met.no, AccuWeather, and Finnish Meteorological Institute) - condition text is each provider's own raw wording, not normalized into a shared vocabulary across them.