WEATHER APPS ON TENERIFE

Weather Apps on Tenerife: Convenient but Still Fallible

Weather apps on Tenerife are often used out of convenience, but it’s essential to remember that these are automated applications fed by data and algorithms, not human expertise.

In my article Damn Weather Apps, I was quite critical of these tools. At the time of writing, advanced computer systems like sophisticated measuring stations, data transmission technologies, artificial intelligence, and other innovations were not yet available. As technology advanced rapidly, the article aged equally fast and is no longer entirely up to date.

More Insights

Mario Egthuijsen, who has helped me write meteorological content in the past, shared his feedback on the article. Since he knows what he’s talking about, I trust his judgment. His reaction adds valuable context to our understanding of weather apps:

I agree that you should be cautious with weather apps. Since your article, many more apps have emerged. Personally, I use I’m Weather, which provides access to all European weather models, including the American GFS. Resolution is a significant factor in determining an app’s accuracy and reliability. By the way, the ECMWF’s best resolution is not 7 km, as you mentioned, but 9 km. Even with this, Tenerife benefits from far more grid points than the GFS model with its 22 km resolution.

It’s true that using an app to check weather predictions beyond 4 to 5 days is pointless. One slight atmospheric change, and the entire forecast shifts. Many models still struggle with accurately accounting for daily temperature and wind variations in their calculations. Since I’ll be visiting Tenerife for 10 days starting December 30, I’ve noticed that most models predict temperatures 3 to 4 degrees lower than they actually are. The recent calima wasn’t well captured either—it was only detected once it had already arrived, and even then, forecasted temperatures were far below the actual 25–31°C range (31.2°C in Puerto de la Cruz was reportedly the highest December reading there).

Challenges with Weather Apps

Mario continues:

Another issue is how apps present data. What use is an icon showing a cloud and some sun for Playa de Las Américas? If the sun shines for just one hour and the rest of the day is cloudy due to trade wind clouds, the icon may technically be accurate, but most tourists interpret it as sunny with occasional clouds.

Apps also struggle with the trade wind clouds above and around the islands. As you’ve noted, they handle this poorly. Then there’s precipitation probabilities—these provide a daily percentage for a single location but are often misleading. If it rains for just 30 minutes, does that make the probability 100% because the app predicted rain at some point? Or should it be much lower? I use Weather Pro—not bad, but even it can get precipitation chances very wrong.

One tip: If you have an iPhone or Mac, try Weather Mate. It’s not great for forecasts but excellent for accessing amateur weather stations. During Storm Dorothea, I saw rainfall readings between 15–20 mm in the eastern hills, while Reina Sofía Airport recorded only 6 mm.

Predictions Are Misleading

Mario is spot on. While weather apps are far more accurate now thanks to advancements in meteorology, technology, and computational methods, they’re still not 100% reliable. Regular users will notice discrepancies between predicted and observed weather. That’s why meteorologists use terms like observations and forecasts rather than predictions.

For my part, I use the built-in weather app on my iPhone for convenience. However, for accurate answers to the question, “What weather can we expect?” I rely on Tenerife’s meteorological agency, AEMET, where trained meteorologists carefully check and double-check all data.

Guy Devos © Illustration
Weather Apps on Tenerife ©