Putting the Rain-Predicting Apps to the Test

RainAware Reigns Supreme in Precip-Predicting App Market

The Background

Two things are abundantly clear at this point in civilization. One, weather technology is becoming ever more complex and sophisticated, capable of detecting things once thought impossible. And two, man is always seeking to gain some measure of “life management” over the whims of Mother Nature. And so it seems only natural that new precipitation-predicting weather apps have emerged on the scene, ready to guide us through the day without getting wet.

The Test

We decided to give RainAware, Dark Sky and Ourcast, three of the newer rain-predicting apps, a test on a stormy night in Minnesota. (See also our exclusive interviews with the founders of RainAware, Dark Sky and Ourcast.) We began checking each app beginning at 6:45 p.m. and subsequently recorded their predictions every 15 minutes thereafter until the rain began. Likewise, once it became clear the rain would eventually end, we recorded the apps’ predictions for rain-ending times starting at 12:45 a.m., and then rechecked the apps every 15 minutes until the rain ended.

The Results

As our results in the accompanying graphic reflect, RainAware was the most accurate in determining both the beginning and ending times of the rain. RainAware locked on to the precipitation early and rather accurately. It came quite close to predicting the actual time of rain onset a full hour and a half before it arrived. And while it initially waffled a bit on the actual start time and experienced a server problem that made updates inconsistent for a short period, it provided a rain starting time nearly three hours in advance. In contrast, Ourcast seemed to think it was raining a full two hours before a single drop fell from the sky. Dark Sky, which doesn’t predict rain until it sees its arrival within a one-hour window from the current time, was slow to pick up on the ultimate arrival of the rain. At 8:45, Dark Sky predicted rain would begin at 9:35, when in fact it began at 9:15.

An analysis of predicted starting and stopping times revealed that RainAware was the most accurate.

RainAware was equally impressive in predicting an accurate time for the end of the rain. At 12:45 a.m, RainAware predicted the rain would end at 1:23. Dark Sky predicted the rain to last through 1:45 and Ourcast predicted the precipitation to last through at least 2:10 a.m. The rain ended at our location at 1:20.

Ground Clutter a Challenge for Dark Sky and Ourcast

Both Dark Sky and Ourcast also had challenges grasping the ultimate end of the rain. Both apps – to varying degrees – continued to think it was raining after the rain had actually stopped. The inability to decipher ground clutter from precipitation appears to be a continuing problem for both Dark Sky and Ourcast, as we’re seeing a reoccurrence of the problem as of this writing (May 2, 9:50 p.m.). While not perfect, it’s clear to us that RainAware is the superior app when it comes to detecting real rain from radar noise.

RainAware

In addition to RainAware’s actual performance in predicting rainfall, we also think the app’s features are generally the best of the apps tested. RainAware provides the longest lead time in rain prediction with a three-hour window. The three-hour window “messages” also come with informative statements about possible rain events even when there are no specific rain times. For example, it will suggest “showers could develop at any time,” or “dry now but a growing chance of rain” that we think provide a valuable “heads up” to users.

We also like the very simple but effective 7-day weather forecast that RainAware includes. While the main purpose of the app is to provide start and stop times for precipitation, the big-picture forecast means there’s no need to consult other apps for more general weather information.

Users desiring a pretty or interactive radar may be disappointed by RainAware. However, we think the radar is far secondary to the main function of the app, which is to provide start and stop times for precip. Besides, there are a number of other apps on the market dedicated exclusively to radar.

Dark Sky

Dark Sky brings undeniable beauty to radar depictions, which historically have been clunky and jittery. We also appreciate that all the information is boiled down to one screen, which includes confidence and forecast of precipitation strength. The app also provides the ability to backtrack two hours on the radar so that one can see what amount of precipitation passed through the area. Clearly, there’s some good innovation at work in this app.

However, we think the one-hour forecast window is insufficient, particularly when there’s no other information related to the overall forecast. If it’s noon and you’re wondering about the odds of getting in an evening softball game, Dark Sky is not going to help you.

Ourcast

The feature we liked best about Ourcast, the only free app among the three we tested, was the ability to move quickly and smoothly from one point on the map to another. This functionality is not present in Dark Sky or RainAware. Also, if you’re a fan of being social with your weather, Ourcast provides the opportunity to commiserate with your neighbors. Otherwise, we weren’t particularly impressed by Ourcast.

Conclusion

For our money, based on both the results of our test and its overall features, RainAware is the best precip-predicting app on the market.

The Minnesota Forecaster provides analysis of both the weather and those who forecast it. For periodic updates, follow us on Twitter and Facebook.