A dark place can still have a cloudy sky. Starglow is a stargazing forecast app for iPhone that provides a 48-hour view of observing conditions by location, so planning a night out starts with the weather over the place you intend to visit.
Choose a point on the map and read its hourly forecast. Cloud cover is separated by altitude, which helps explain why two nights with similar total cloud can suit different targets. Save places you return to and Best Location Tonight ranks them by conditions; the Dark Site Finder adds a light-pollution map and nearby options. A darker location may still be the wrong choice if its forecast is worse than a familiar spot closer to home.
I'd start with the saved locations. That makes the forecast answer a decision you can act on: which of your usual spots looks promising tonight? The developer's weather guide explains the rows and the meaning of its model-agreement count. Early US App Store reviews asked for clearer explanations of the colors and weather measures, but those predate the substantial October update; they aren't evidence that the same explanation problem remains.
Starglow suits iPhoners who already have a few observing or photography locations in mind. I'd use the comparison to narrow a trip, then recheck the forecast before leaving, since a planned clear window is still a prediction.
