I have heard the same regarding 5xx errors in the past couple of months. I am also working on open-source weather API https://open-meteo.com/. It covers most of WeatherKit features and offers more flexibility. You can either use the public API endpoint or even consider to host your own API endpoint.

Forecast quality should be comparable as the API uses open-data weather forecasts from the American weather service NOAA (GFS and HRRR models) with hourly updates. Depending on the region, weather models from other national weather services are used. Those open-data weather models are commonly used among the most popular weather APIs although without any attribution.

If you have any questions, let me know!

Wrote you a mail. followed the project since a longer time!

Here’s where we ended up:

Apple resolved the issue after 48 hours of performance disruptions. Though I further noted one five minute disruption on 4/3 at 6pm ET. They still haven’t responded to our initial ticket.

We’ve worked around this by implementing Pirate Weather as an emergency fallback (it was an easy option since they are fully compatible with DarkSky’s API). But Pirate’s baseline performance is worse, and they don’t have a plan that supports more than 250k requests/month.

We may have to eventually switch to a different provider.

Catastrophic since the beginning. Has not the same historical data like Darksky and the initial setup was annoying.

It's annoying that one needs an apple device to pay for an subscription of that API..

Because of that having a fallback for all the outages.

The historical limitation should be emphasized - requests for dates before August 1 2021 will return a success status, but always with the data for 8/1.