A weather app built for one island
Weather runs this island. Whether you fish, pour concrete, guide a snorkel trip, or just want to know if the beach is worth the walk, the first question of the day is the same: what’s it going to do? Belize Pulse started as an attempt to answer that question properly for Ambergris Caye, and only Ambergris Caye: San Pedro town, the stretch north past the bridge, Secret Beach, and the south end.
Here is what makes it different from the weather app that came with your phone.
Measured, not modelled
Open most weather apps on Ambergris Caye and the “current” temperature is not a measurement. It is a computer model’s best guess for a grid square that is mostly water. On a clear September morning the model said 28 °C while the thermometer at the San Pedro airstrip read 32 °C. Four degrees is the difference between a pleasant walk and a hot one.
Belize Pulse leads with the measured numbers. The National Meteorological Service of Belize runs an automatic weather station at the airstrip that reports every fifteen minutes: temperature, humidity, dew point, pressure, wind speed and gusts, and rain in the gauge. Those are the numbers at the top of the screen, labelled with the time they were taken. The model estimate is still there, in small print, for comparison.
Rain you can see coming
The Met Service’s radar at Philip Goldson Airport sweeps the whole country every few minutes and publishes the pictures. Belize Pulse reads the last three frames, measures how the rain cells are moving, and projects that motion forward to answer two questions people actually ask: when does the rain reach my house, and when does it stop?
When rain is on its way, the home screen turns amber or red and says so in plain words: “Rain in about 25 minutes, clearing by 12:30.” A rain clock shows the next ninety minutes in ten-minute bars, taller for heavier rain. When nothing is coming, it says “Dry for the next 2 hours” and tells you how far away the nearest rain is, because an empty radar is the most confident forecast there is.
This part is experimental, and we say so on the page. The radar pictures are published fifteen to thirty minutes behind real time, so every estimate works from a frame that old, and the system has to prove itself through a wet season. We are grading it against the airstrip rain gauge, and the scorecard will be public: how many rain events, how many called within ten minutes. Showing the misses is the only way the hits mean anything.
The sky is the screen
Instead of boxes and tables, the whole screen is one picture of the sky as it is right now over the reef: blue on a clear morning, grey when it’s overcast, slate when a squall is coming in, stars at night. The instruments sit on top of it. A compass dial shows the wind, with the arrow on the rim at the direction the wind is coming from, the way sailors read it. A small wave shows the sea state at the reef. A tide line runs along the bottom, small, because tides here are under a foot and rarely change anyone’s plans.
The rule we followed: every graphic is a real instrument with a real reading, and everything text-heavy lives behind one “More” button.
Made for a phone, works without signal
More than nine in ten people will use this on a phone, often on a dock or a boat. So Belize Pulse installs like an app: on Android, tap Install; on iPhone, tap Share, then Add to Home Screen. It opens full-screen straight to the glance view, and it works offline, showing the last data your phone saw with a clear note saying so. It refreshes itself when you come back to it, and switches between Celsius and Fahrenheit, kilometres and miles, with one tap.
Power notices, in the same place
The second thing that runs this island is the electricity supply. BEL posts planned outages and load-reduction notices on its Power Updates page; Belize Pulse checks that page every thirty minutes and puts any notice for San Pedro or Ambergris Caye as a banner across the top of the home screen, amber for planned work and red for a load reduction, with the date, hours, and feeder. Tap it for the full notice, quoted from BEL with a link. BEL remains the only authority on outages; we just save you the trip.
What’s next
Belize Pulse is a work in progress, built by one household on the island with a lot of help from software. In the coming weeks: the public accuracy scorecard for the rain forecast, a twelve-hour wind outlook for the boat crowd, and rain alerts you can opt into on your phone. After that, the same screen for Caye Caulker, Belize City, and Placencia, each with its own station and radar view.
Where the data comes from
Measured conditions, radar, forecasts, and tides: the National Meteorological Service of Belize. Power notices: Belize Electricity Limited. Lightning: NOAA’s GOES-19 satellite. Storms: the U.S. National Hurricane Center. Model forecasts: ECMWF, NOAA GFS, DWD ICON, and ECMWF’s AI model, blended through Open-Meteo. Belize Pulse is independent and non-commercial, and it is not an official warning service: for warnings, follow the Met Service and NEMO.
Try it at belizepulse.com, and tell us what’s wrong. Every correction makes the island’s forecast better.
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