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ZELUS: Heat and Lightning Safety Redefined

The Zelus system offers unparalleled safety for you and your team, providing cutting-edge WBGT readings and lightning detection.


WBGT Readings

The most advanced system for WBGT readings

The Zelus system uses advanced algorithms and data sourcing to provide an accurate WBGT reading at your fingertips without the need for any hardware.
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Lightning Detection

Lightning Detection

The Zelus system will alert you of lightning anywhere in the United States and let you know when the lighting has passed.
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Risk Management

Risk Management

With just the push of a button, the Zelus system electronically signs, dates, and times stamps the data along with any activity modifications made.
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Alert Notifications

WBGT alerts

With the Zelus system, you can be across town or across the world and still be alerted if the WBGT gets too hot.
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Location independent

Be Anywhere

The Zelus system operates without hardware, enabling you to receive WBGT and lightning alerts for your saved locations from anywhere in the world.
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  • Do you offer discounts to schools or organizations


    Yes! Please email us at info@zelusports.com and we will provide you with group pricing.

  • How does the app determine WBGT


    The app takes hyperlocal (less than 2.5km resolution) weather data that includes air temperature, relative humidity, solar irradiance, angle of the sun, cloud cover, wind speed, atmospheric pressure, and dew point then uses this data in complex mathematical algorithms that have been developed by the NOAA/NWS and Ph.D.s in meteorology.

  • Where do you get your weather data?


    Data is sourced from the world’s most advanced weather datasets including: weather station data, NASA MODIS Satellite data, precipitation radar, weather models, multi-sensor satellite based precipitation (NASA GPM/TRMM), the MERRA2 and ERA5 re-analyses, the GLDAS re-analysis (Agro API), and the Tempest lightning network.

  • Do you have an API?


    No. Our software is unique and patent pending. You can only get these services through our app.

  • Is the WBGT accurate


    Yes. In a data set of over 20,000 unique readings from May to November, WBGT calculated from weather parameters were routinely within 1 degree Celsius of WBGT using a gold standard WBGT device. https://econet.climate.ncsu.edu/wp-content/uploads/2021/05/WBGT.pdf

  • Does it work on artificial turf?


    Yes. Contrary to popular belief, the playing surface does not change the WBGT to any appreciable degree.

    Sources: Grundstein A, Cooper E. Comparison of WBGTs over Different Surfaces within an Athletic Complex. Medicina (Kaunas). 2020 Jun 25;56(6):313. doi: 10.3390/medicina56060313. PMID: 32630486; PMCID: PMC7353887.

    Cheuvront SN, Caruso EM, Heavens KR, Karis AJ, Santee WR, Troyanos C, D’Hemecourt P. Effect of WBGT Index Measurement Location on Heat Stress Category Classification. Med Sci Sports Exerc. 2015 Sep;47(9):1958-64. doi: 10.1249/MSS.0000000000000624. PMID: 25628176.

  • I have a different question!


    Many more questions are answered in our knowledge base at help.zelusports.com. Or you can email us at info@zelusports.com.


We chose the reviews, so you know they are going to be good.  But they are genuine and we are proud of them!

Want to know the WBGT? This is the app for you.
This app is a great example of a tool that does exactly as advertised. Do you want to know the WBGT? This will give it to you. It will also allow you to see various scales for WGBT and their recommendations for outdoor activities.

Apple Review

Brilliant! Thank you for making an easy to use app for getting current, real-time WBGT!

Noel Field
Google Play Store

I love the product. I think it is really easy to use, we can document when temperatures are taken and the precautions we have taken so from a liability perspective it’s fantastic. It’s also great because we can ensure we are keeping our students safe and don’t have to rely on a trainer being on site all the time. It’s increased awareness and autonomy throughout our coaching staff to make wise and safe decisions regarding student participants. I love it because I can check from home and be sure that coaches are operating with the same information I am. I’ve really enjoyed having it. 

Seth Wilber
Activities Coordinator Fort Zumwalt East High School

Zelus has enabled Mercy Sports Medicine to broaden its sphere of influence when it comes to protecting athletes during dangerous heat. The remote capabilities have solved our staffing issues, and the user friendliness allows our community partners to have active participation in the safety measures. The cloud based tracking system increases accountability and ensures protocols are being followed.

Mike Lane
Mercy Sports Med Outreach – Manager

We chose the reviews, so you know they are going to be good.  But they are genuine and we are proud of them!

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