The obvious answer is “charge a reasonable price”.

Many services like AccuWeather do that, including having a limited free tier for experimentation or niche applications.

The real problem though is that the value of the data isn’t just the cost of storing and making it available - in many cases its strategic. This is why e.g. the Google Maps API gives you pre-rendered map tiles and curated results, but you don’t get access to the raw data.