In the week or so that I've owned an Apple Watch, I've realized just how much I value this line-based presentation. Seeing forecast highs and lows along a forecast line is much more reliable for day planning. So far, Weather Nerd is the only weather app available for Apple Watch that gets it right, and I'm happy to pay its developer for the information-rich display it puts on my wrist.
For years, weather services typically only reported a high and low temperature for a single day. But this is very misleading on days when, say, a high of 50 occurs at daybreak and a low of, say, 30 will occur late afternoon. Such situations are not uncommon.
I hope that Dark Sky and other weather apps follow the path set by Weather Nerd and bring their lines to the Apple Watch, which to me is the most ideal platform yet for checking weather.