This sounds as though it could be a nice replacement for the Dark Sky API that Apple is going to lock us out of.
The ClimaCell API docs say the weather API offers forecasts for 1) realtime, 2) hourly, 3) nowcast, 4) daily
The free-tier pricing plan [1] apparently offers limited access to 1-3 but no access to 4. That's too bad, but then no paid-tier plan offers 4, either. So, I have to wonder, Am I missing something or are they?