Why Do You Need My Location?

To generate your weather forecast.

Our backend system runs a software package called Open-Meteo, which receives a steady stream of weather model data from the major meteorological institutions around the world. This includes the NOAA/NWS GFS and HRRR models that your local meteorologist also uses for the daily weather report on television.

We can't generate your forecast without knowing where you're at. That's the plain reason.

Do You Get My Location Just Once, Or All The Time?

Only once. The app will request your permission to share your location right after you tap the button to accept the terms of service, the first time you run the app.

Also, if you press the "Update My Location" button in the Settings Tab, then the app will request your location once more, at your request.

We DO NOT track your Location at any other time.

We recommend that you select the "Only While Using The App" option on Android devices, or the "Allow Once" option on Apple devices, unless you tend to travel with your evaporative cooler...

Which would be pretty neat, in fact! If you use evaporative cooling in an RV or travel trailer, please reach out to us to share your experience! It sounds like a fascinating life hack!

Should I Share Approximate or Precise Location?

Short answer: it depends.

Longer answer: if you're within 5 miles of nearby hills, valleys, mountains or large changes in elevation, then choose Precise. If you're far from those geographical features, then you can choose Approximate and it's probably as good as a more precise location.

The reason for this is that our weather model data is enhanced with an extremely high resolution elevation map that is used to correct for air pressure differences due to small elevation changes for terrain that isn't flat. This elevation map is called the DEM90, or the Digital Elevation Map, 90 meters resolution. It's an open-source elevation model that captures very fine height detail for almost all the land area of the whole planet! Well, 91%. (Thank you to the fine folks at EarthEnv.org, including their paper about the construction of the DEM90 dataset.)

Because this elevation map is at a much higher resolution than most weather model outputs, 90 meters versus 3 kilometers, it enables the Open-Meteo system to apply very precise corrections to the weather forecast, after accounting for the elevation differences. It's a fact that higher elevations have lower air pressure, lower temperatures, and other differences in humidity metrics like dew point, which can be factored back into your weather forecast. This is some advanced math, and we're grateful for the efforts of the project leader, Patrick Zippenfenig, of the Open-Meteo project.

For the most accurate evaporative cooler forecast, you should choose Precise for your Location sharing permission.

However, you're always free to choose Approximate and you'll get a resonably good weather forecast, as long as you're surrounded by flat terrain for about a 5.5 mile radius. This corresponds to a 3x3 grid of HRRR model data.

Do You Ever Share My Location?

No. Never. That's absolutely against our commitment that your personal data will not be sold or shared with third parties.

Will You Use My Location For Advertising?

Possibly. Why?

In a word: Relevancy.

You probably don't want to see ads for businesses located hundreds of miles away from you. And advertisers probably don't want to pay to show ads to people who live so far away, either. In both cases, nobody wants irrelevant ads.

Since ads are only shown for non-Premium members, we want to at least try and make the ads a little more meaningful and relevant.

Here's a specific example:

Suppose a hardware store in Wink, Texas would like to advertise a special deal for local residents with evaporative coolers in our app, they wouldn't want to show that ad to people who live 2,000 miles away. Especially if there's a much closer vendor who would like to reach people in their operating area.

We can ensure the ads are kept geographically relevant, without sharing anyone's specific location to anyone.

We will never share your location with any third party, including advertisers.

Do You Use My Location For Any Other Reason?

Yes, for estimating your electricity rates.

We set your default electricity rate to either the average rate for the US State where you reside, or for non-US members, we set the default electric rate on a country-by-country basis. You can customize this rate under the Settings tab.

There's such a wide variation in electricity pricing ($/kWH) across the US and the world that we felt it didn't make sense to pick a single value for the default price value. That would be very imprecise and serve everyone very poorly.

Instead, we rely on a combination of public data sources, including the US Government's Energy Information Administration (EIA), to provide a table of typical electricity rates by US State, and other public sources for non-US country rates.

Remember that you can adjust and correct your Electricity Rate ($/kWh) in the Settings Tab of the app to match your specific average price per kilowatt-hour.

What If I Don't Have A Flat Rate For Electricity?

We don't currently support Time-Of-Use (TOU) plan price modeling. If you are on a Time-Of-Use plan, where you pay a different price during some parts of the day or week, then the best way to set your electric rate in the app is to pick a typical, or average price per kilowatt that you're most likely to pay while using the evaporative cooler. If you tend to only run your evaporative cooler during daytime hours, and not the evening, then be sure to adjust the slider to match your daytime rates.

But we're getting off-topic at this point, so the short answer again is: We use your location to help select a reasonable default electricity rate for your US State or non-US country.

If I Update My Location, Do You Keep The Old Location?

No. We don't need it, and we don't want to keep it.

Whatever Location you share with us, will overwrite the previous location and we don't keep a record of past locations.

One small caveat: We do maintain regular backups for ordinary data security, however, those backups are purged after a set period of time (around 2 months).

All This Talk About Location Privacy Scares Me. Should I Be Concerned?

No. We want to be as transparent and open about how we respect your privacy, so this page is our best effort to share everything we can about the ways we protect your personal information.

If we could provide a forecast without your location data, we definitely would... But that's not practically or technically feasible.

Read Our Privacy Policy

On the Tenth Light website, linked here, you can read our full Privacy Policy

If you have any questions or concerns, please feel free to email us at: support@TenthLight.com

Anything Else?

Wow! If you've made it this far, then thank you!

And... Congratulations! You're obviously someone who cares about your information security and privacy.

We hope you appreciate our transparency and commitment to protecting your privacy.