Weather integration - recommendation?

[Hellis81]

@stevemann

METARS is updated hourly, mostly by automated stations.

Around here it’s 30 minutes.

@stevemann

Open Weather Map is free up to 1,000 API calls in 24 hours. Meaning you can hit it every 2 minutes and be below 1000 calls. The data is updated continuously from thousands of measuring stations and is surprisingly accurate.

Just because you can update every two minutes doesn’t mean the data is updated that frequent.
What is the actual update frequency?