Current poolAwaiting reading
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Free worldwide outdoor-pool forecast
Free 5-day pool temperature forecast
Stored on this devicePredict your outdoor pool's water temperature from local weather, pool size, covers, heaters, and one current reading. No account or smart sensor required.
Free to useWorldwide weatherFive-day outlookBrowser-local data
Next 48 hours
Daily highs & lows
Add one current pool temperature to calculate daily lows and highs.
5-day outlook
Pool temperature trajectory
Pool + rangeAir at 2 mDaily low / high
A pool forecast built around your water—not a generic weather widget
Pool water changes slowly and responds to more than the afternoon high. Pool Forecast starts with one real reading, applies local weather to your pool's physical profile, and shows the likely direction over the next five days.
Describe the pool
Add its location, dimensions, installation type, and any cover or heating schedule. Volume determines how much energy the water can absorb.
Add the water now
Enter a thermometer reading or connect a compatible Govee sensor. That measurement anchors the forecast to your actual pool.
Read the five-day outlook
See the modeled water curve, estimated range, daily highs and lows, weather forcing, and the confidence stage.
What the model considers
The forces that warm and cool an outdoor pool
The model integrates the heat balance in ten-minute steps. It keeps each factor separate so changes behave physically: brighter sun cannot make the same pool colder, and more water takes more energy to move by the same number of degrees.
Explore the pool-temperature factors →Shortwave radiation adds heat across the exposed water surface.
Moving, dry air can pull substantial heat from uncovered water.
Convection and longwave radiation exchange heat with the atmosphere.
Volume sets thermal mass; surface and walls set the exchange area.
Scheduled covers reduce evaporation while also changing solar gain.
Heater output or solar collectors contribute only during their schedule.
Honest scope
Made for open outdoor residential pools
Use it to plan swim days, watch an overnight cooldown, or understand how the next weather pattern may move your water temperature. The first result is explicitly labeled an estimate and improves only when your own history passes chronological checks.
- Supported
- In-ground and above-ground outdoor pools, metric or imperial units, worldwide locations, common covers, and scheduled heating systems.
- Not modeled
- Indoor pools, spas, liquid covers, winterized pools, changing shade, chemical treatment, freeze protection, or equipment-control advice.
- Private by design
- Your pool profile and readings remain in this browser. No public account or cloud pool history is required.
Learn what the forecast can—and cannot—tell you
Practical explanations based on the same bounded physics used in the app, with limitations kept visible.
Forecasting guide
Can weather predict pool temperature?
See why sun, wind, humidity, rain, and the current water reading matter more than air temperature alone.
Read the guide →Pool physicsWhat changes pool water temperature?
Understand thermal mass, surface area, covers, installation type, and scheduled heating.
Read the guide →Choosing a toolForecast or thermometer?
Use a reading for what the water is now and a forecast for where it is likely to go next.
Read the guide →Pool temperature forecast FAQ
Can you predict pool temperature from the weather?+
Weather is necessary, but air temperature alone is not enough. Pool Forecast combines the current water temperature with hourly sunlight, air temperature, humidity, dew point, wind, rain, and cloud cover, then applies those conditions to your pool's volume and exposed area.
Do I need a smart pool thermometer?+
No. One current water-temperature reading from any ordinary pool thermometer is enough to create the first estimate. A compatible Govee Cloud thermometer is optional and can refresh readings automatically while the page is open.
How accurate is the pool temperature forecast?+
A new pool starts with a bounded physics estimate, not a guarantee. Accuracy depends on the starting reading, weather forecast, shade, equipment details, and conditions the model cannot observe. With enough day and night readings, the app tests whether pool-specific calibration improves on its default model before using it.
Does the forecast account for pool covers and heaters?+
Yes. You can add solar or solid covers, gas or electric heaters, heat pumps, and solar thermal collectors with local-time schedules. Pool Forecast estimates their thermal effect; it does not recommend when equipment should run.
Does Pool Forecast work worldwide?+
Yes. Location search and weather coverage are worldwide where Open-Meteo provides data. The app stores an IANA time zone with the pool so cover and heater schedules follow local time, including daylight-saving changes.
Is Pool Forecast free and private?+
Yes. The forecast is free, requires no public account, and keeps the pool profile, readings, cached weather, and forecast history in this browser. Optional support payments do not unlock features or change results.
Help keep the forecast moving
Support Pool Forecast
Did Pool Forecast help you choose a better swim day or avoid unnecessary heating?
Pool Forecast remains free for everyone. Optional support helps fund careful, independent improvements without unlocking features or changing forecast results.
Hosting & servicesKeep the forecast, weather relay, and supporting services reliable.
Forecast validationCompare issued forecasts with real pool readings and improve confidence reporting.
Sensor integrationsAdd and maintain safe connections to more pool-temperature sensors.
Mobile & browser improvementsMake setup, forecasting, and history easier across phones and browsers.
This is support for software already provided, not a charitable or tax-deductible donation.