Apple acquired the hyperlocal weather app, Dark Sky, in 2020 and, at that time, it was highly likely that it would shut down Dark Sky's apps and website in the same year. However, the company also said that there would be "no changes to Dark Sky for iOS" at that time.
In 2021, we see that there is a small update to the Dark Sky blog that appears to be adding a new shuttering date for the Dark Sky iOS App, API, and website. Adam Grossman, the co-founder of the Dark Sky weather app, wrote:
Support for the Dark Sky App service for existing customers will continue until the end of 2022. The iOS app and Dark Sky website will also be available until the end of 2022.
We hear this news shortly after Apple announced an overhaul to iOS' inbuilt weather app during WWDC. While the wording on the website doesn't explicitly say that the service will be "shut down" per se, it does seem that it is reaching its end of life.
Previously, the Dark Sky website was scheduled to shut down in August 2020 while the API was scheduled to for the same at the end of 2021. Apple already killed Dark Sky's Android app back in August 2020.