Should you cancel your tee time? Maybe you’ve got a few more holes to go but the sky is darkening. Should you cut it short or continue playing? Will you risk being caught in a downpour or a thunderstorm?


What can be worse than a rained out wedding? Save the cake and your hairdo too with RainAware! A must for anyone planning outdoor gatherings.

Water Sports

Out on the lake? Skies are darkening. Should you get to shore? You might even have an app showing weather radar but can you tell exactly when it will hit?  No worries, RainAware knows.


Nothing is worse than being caught outdoors in a thunderstorm on your bike! With RainAware, you will never be suprised.  And don’t worry, even on the go, RainAware knows where you are.


Got an outdoor photo shoot? Maybe you can get it in before it rains, or maybe you should reschedule. One look at RainAware and you’ll know what to do.

Out On The Town

Going out tonight? What if you get stuck in a long line at the club? Don’t get soaked, get RainAware! Be the person in your group that knows when it’s gonna rain…your friends will thank you!

When Out and About

It’s pouring rain but you need to get across the parking lot to your car. Should you make a run for it, or wait it out? Maybe your kids are at the park or swimming pool, is it time for them to come home?

Construction Workers

Is now a good time to pour concrete? Should we continue painting the house or break for a couple hours?

Yard Work and Landscaping

Do I have enough time to get some fertilizer down before it rains? Should I mow the next yard or go to lunch until the rain passes?


Will the game resume or be cancelled? Should you leave now to beat the traffic? Perhaps you are an umpire. Should you call the game?

At Outdoor Events

RainAware is a must-have for large outdoor gatherings and events. With advanced warning of approaching rain or storms, you’ll be able to take action quickly and beat the crowd! Event planners will operate more smoothly and efficiently with RainAware!


Determining when precipitation will occur at a user’s location is a very complex process. Our team evaluated many different methods and realized that none of the existing forecasting methods provided the forecast quality and reliability we needed. So, we developed a completely new method that is the cornerstone of the RainAware system.

It is so difficult to predict precipitation times at any given point, that very few meteorologists even attempt it. Those that do use a method called “linear extrapolation”. Basically, a storm motion is determined from environmental data, and is used to move radar echoes forward in time. A computer then examines the future positions of the echoes, and determines when the echoes will hit the location in question.

But “linear extrapolation” makes two huge assumptions. One, that the radar echoes will move in a straight line, and two, that they will not change shape or intensity before arrival. Both of these assumptions result in poor performance. Unfortunately, nobody can predict these subtleties until they occur.

Our method understands that weather is extremely complex and changes by the minute. RainAware doesn’t fall prey to either of these assumptions. Instead, complex mathematical methods are used to examine literally thousands of possible storm motions, with a different probability of occurrence for each one. In a fraction of a second, RainAware has developed a massive ensemble of outcomes for every 5 minutes out to 3-hours.

The end result is much more than just a “forecast rain time.” RainAware’s scheme results in a high-resolution table of precipitation probabilities, intensities, and types.

The user can then decide at what confidence level they would like to be alerted for precipitation. This provides ultimate control to all types of users, whose needs may vary.

So while RainAware provides an accurate and simple “answer” in the form of precipitation times, as you can see there is much more going on behind the scenes. These differences clearly set RainAware apart from any weather forecast available today.

We hope this explanation has helped you understand a little more about RainAware.

Weather that works, is weather you can use!


The RainAware API is an easy and fast way to get precipitation timing information for anywhere in the USA. Whether you need to monitor rain sensitive locations or have a big invention in mind, our API is the most accurate and economical way to get customized weather information.

The RainAware API provides:
- Rain arrival and departure times.
- Precipitation intensity.
- Thunderstorm vs stratiform rain.
- Snow/Sleet/Ice information.
- Fully customized data is available to fit your needs.

Spatial Resolution:
- 1 km

Time Step
- Every 5 min, up to 3 hours out

Human Integration
- The RainAware system can easily accept human input, unlike any other system out there.
- Motion vectors, reflectivity thresholds, clutter reduction…all this can be customized on the fly!

Some great uses for the RainAware API:

- Provide rain times for scheduled events such as weddings or outdoor functions.
- Alert employees in the field of approaching rain.
- Produce “along-route” relative rain times for mobile navigation systems.
- Create an awesome weather app.
- Add rain times to your existing weather app.
- Develop a rain-time widget for your sports website (PGA, MLB, NASCAR, USTA, Concerts….)

The possibilities are endless!

Contact us and ask how you can hook your company into the RainAware system today. Be the FIRST to offer some of these unique services!

RainAware User Guide

Program Startup and Location Services

When you open RainAware for the first time, you will be prompted to allow RainAware to use your phone’s location. This will allow us to produce a tailored forecast for you, wherever you may be. RainAware does not know who you are, and your location will remain anonymous. If at any time you would like to disable this feature, you can turn it off by going into your phone’s settings. In iPhone, go to Settings > Location Services > RainAware. You can also turn it back on here if it accidentally becomes disabled.

In version 1.0.0, if RainAware cannot determine your location, a random location is used. Luckily there are multiple ways in which your location can be determined so this usually does not occur unless you do not enable GPS. However, we expect to enable a manual input of location in the coming update.

Your location is shown in the”Location Bar” across the top of the screen. Tapping this bar, as well as the “Refresh” button next to it, will force a refresh of your data. You do not have to worry about doing this as RA automatically refreshes every minute, but you may need to in rare instances. Tapping the location bar will also return you to your default/GPS location if you previously switched to a different site.

RainAware Main Screen

Main Window – This is where your precipitation threat is displayed for the next 3 hours. There are three ways to display this data, and you can simply swipe left or right to reveal the other screens. Here is a summary of each screen:

Default Screen – This is the screen you see when you first open RainAware. It consists of a “Text Bubble” which will display precipitation start and end times, if applicable. If there is no threat over the next 3 hours, it will simply display “Dry”.

Rain Clock – Swipe to the left to reveal the 1 hour RainClock. Also on this page is a text bubble, similar to the default screen. The RainClock is similar to a stopwatch, where “Now” is always at the top. When precipitation is going to hit you within 1 hour, you will see this clock filled with colors, according to the intensity of the precipitation. Each minute, the “colors” will rotate counter-clockwise until it hits “Now”, in which case, it will be precipitating.

Three Hour Bar Chart – Swipe to the right to reveal the 3 hour bar chart. Each bar is 5 minutes, and the chart spans the next 3 hours. Current time is on the left. Similar to the RainClock, color of the bars indicates intensity. The height of the bars indicates how likely rain is to occur in that exact 5 minute period. Taller bars mean precipitation is more likely. Very short bars mean either showers are very small, or you are on the fringe of an area of precipitation, in which case it will probably miss you.


What is “Rain”? – Sounds simple, but we need to define it. Is it drizzle? A few sporadic drops? A steady, street wetting shower? Answer: We try to detect almost all rain, even if very light. We realize some users might not care about very light rain. At the same time, we may not always detect the lightest drizzle. The best thing to do is refer to the color coding on the 1-hour rain clock or on the 3-hour bar graph. If it’s blue, that means very light. If it’s dark green or yellow, that is more moderate rain and everything is getting soaked. Oranges and reds are for heavy thunderstorms. So take note of the intensity color, and plan your activities accordingly!

“Rain is on the way!” – When you see this message, it means that precipitation has been detected upstream of you, and is likely to affect your location within the next 3 hours. The probability of precipitation is ABOVE the red line shown on the bar chart (precipitation threshold).

“There are a few showers in the area” – When you see this message, it typically means very small and/or light showers are in the area, but since they are so sparse, they may not affect you. The probability of precipitation is BELOW the red line shown on the bar chart (the precipitation threshold).

Customized Precipitation Threshold

If you look closely, you will see a red horizontal line across the bar chart. This is your Rain Threshold. The default value is 30% for a 5 minute period. When bars meet or exceed this level, that is when precipitation is forecast to occur, and time estimates are provided. When values fall below this line, RainAware knows there is precipitation nearby, and will continue to monitor for any changes.

You can adjust your rain threshold to meet your needs. Go to the Settings page and choose Low, Medium, or High.

Users who are particularly sensitive to rain may want to choose “Low.” You will probably never be surprised by rain, even light, with this setting. However, this will increase the number of false alarms, or times when rain does not actually occur.

For users who do not want to be alarmed of precipitation unless it is all but certain, the “High” setting is recommended. With this setting, you will receive little false alarm. However, the trade off is that in some instances, the amount of warning time may be decreased.

We recommend the default “Medium” setting, which is the best balance of maximizing long range detection and minimizing false alarms.

Precipitation Ending Times

We require a solid 15 minute span of time with no precipitation in order to say it will “End.” So, if precipitation is only expected to stop for 5 or 10 minutes, then resume, we will not alert you of an ending time, as it will be very short lived. There is no minimum continuous time for onset of precipitation (we will alert you of rain even if it’s only expected to last for 5 minutes).

Sites Page

A really nice feature of RainAware is the ability to monitor and also to go to other places. We provide several categories of pre-determined locations close to you, including Cities (downtown areas), Golf Courses, MLB and NFL Stadiums, NASCAR Raceways and miscellaneous Points of Interest.

Easily see if it is going to precipitate at any of your local sites at a glance. For in depth information as if you were there, simply tap a “Site” and wait for it to load. Please note that precipitation times for your sites use your own timezone. To go back to using your GPS location, either tap the “Return to your current location” button that appears on the Sites page, or tap the Location Bar at the top of the Main screen.

Enhanced Backgrounds

In order to enhance the user experience, we have developed smart backgrounds that change depending on weather conditions and time of day. There are several categories of backgrounds, including day and night, dry, rain, heavy rain, thunderstorms, snow and ice. Typically, the user will see a partly cloudy sky when no precipitation is expected. If precipitation is detected, but still several hours away, the background may become cloudy.

The big changes occur once precipitation is within 1 hour of affecting you. Due to increased confidence, this is when the backgrounds become specific, depicting rainy, stormy, or snowy scenes! For example, you will see vivid lightning for nighttime thunderstorms. You can turn enhanced backgrounds off at any time by going to the Setting page and under “Background Images” choosing “Simple.” This will result in simple color schemes, grey for dry, green for rain, blue with snowflakes for winter precipitation.

Timer Precision

Of course RA attempts to be perfect in its predictions, but in reality, we all know weather can be hard to predict and can change rapidly. Your timers are typically accurate to within 1/2 a mile and 3 minutes by the time rain arrives. You will notice that once precipitation is within 3 minutes of you, we freeze the timer at “< 3 min" and say "It's gonna rain ANY MINUTE!" For longer term predictions, say 2-3 hours out, arrival times will be adjusted as the precipitation gets closer to you, so that by the time it hits, it is very precise. Adjustments are made due to changing shape and size of precipitation over time. With RA, you will be the FIRST to know, as quick as a meteorologist, when conditions change.

Weather Wand

Weather Wand is a fun way to time rain to your exact location. Cast a spell and reveal a magically accurate prediction!

Cast a spell!

Cast a spell!

Reveal the prediction.

Reveal the prediction.

Navigate to a new location.

Navigate to a new location.

Buy Now!
Learn more…

Ballpark Weather

BallPark Wx is a weather app specifically made for major league baseball fans. Whether you’re at the game or watching on television, BallPark Wx will keep you one step ahead of the weather. You can contact us with questions or comments here

Easily see which games have rain, and what time it will end.

View games with winds blowing out to see more home runs!

Save your favorite team for quick access to game times and weather conditions.


We value feedback from users like yourself and use it to make RainAware even better!

We’d like to hear how RainAware worked (or didn’t) for you.

When writing to us, please provide us with the following information:

  • 1) What happened?
  • 2) Date and time of the event.
  • 3) Your location (city and state will suffice, lat/lon is better).

Example of feedback that will be used to improve the system:
“I was in Dallas on June 5th. At around 3:00 pm, the app told me there was no rain, but an hour later a storm hit.”

Example of feedback that will not be used: 
“I can’t believe I wasted 4 dollars, I could have bought a hamburger!”

If you have suggestions on how to make the app interface even better, let us know using the contact form below.


If you have questions about the RainAware system, the app, or just want to send feedback or suggestions, contact us here.


Wall Street Journal – RainAware picked as a must-have app for summer travels 2013


733 days ago

For two years in a row the WSJ (Wall Street Journal) has picked RainAware as a must-have summer app.