PoolCast

Stop guessing whether the water's warm enough. PoolCast forecasts your swimming pool's water temperature for the next 7 days — from real weather data and pool physics, with no thermometer, sensor or smart device required.

Most pool apps make you buy a probe or a connected heat pump first. PoolCast doesn't. Tell it where your pool is and a few details about it, and you get a temperature forecast you can plan around — plus an honest estimate of what it costs to heat.

WHY POOLCAST
• No hardware. No sensor, no probe, no connected device — just your phone.
• A real forecast, not a thermometer. See today and the next 7 days.
• Know before you heat. See the daily running cost for your heater so you never waste money or gas.
• Built on physics. PoolCast models sunlight, air temperature, wind, humidity, evaporation and rain — the same energy balance that actually heats and cools your pool.

WHAT YOU GET
• A 7-day pool water temperature forecast for your exact location
• "Should I heat?" — the daily heating cost for electric, heat-pump or gas heaters, with honest COP-based math
• A clear "warm enough to swim?" read at a glance
• Cover savings — see how much a pool cover would save you each week
• A beautiful temperature chart and a day-by-day outlook
• °C/°F, metric/imperial, wind units and currency — set automatically for your region, changeable any time
• Tune it to your pool: surface area, depth, shade, cover and heater
• Made for phones and tablets, light on battery, gorgeous in dark mode

HOW IT WORKS
PoolCast pulls hourly weather for your location and runs a thermal model of your pool: how much solar energy it absorbs, how fast it loses heat to cool air and wind, and how much evaporation cools the surface. The result is a temperature curve for the week ahead — and if you have a heater, exactly what it will cost to reach your target.

PERFECT FOR
• Pool owners deciding when — and whether — to swim
• Anyone with a heater who wants to cut their heating bill
• Holiday-home and rental owners getting the water ready for guests
• Swimmers and families tired of jumping into a cold pool

PoolCast is free, and there's no account to create. Your location is used only to fetch the forecast.