Where I live (Oslo, Norway), the predictions of Dark Sky and Weather Underground are both less accurate than just making an uneducated guess based on how the weather has been developing the last couple of days. I guess they work better in North America
In my part of North America, you can do better than any weather forecasts that I've ever seen by simply predicting that tomorrow's weather will be pretty much the same as today's. And all forecasts beyond three days are essentially worthless.
