Hi Product Hunt 👋 I'm a public-health physician and a weather enthusiast. I built Thermohélie because one question kept coming up in heat-wave work: not "how hot is the air?" but "how hot is the ground, the roof, the playground, the tarmac my patients walk on?" — and there was no simple tool for it. What it does: for any place on Earth, hour by hour, it estimates the 2 m air temperature and the temperature of sun-exposed surfaces (asphalt, sand, metal, roofing, concrete…). How: a full transient energy balance per surface — direct and diffuse solar on a tilted plane, sky infrared, wind-driven convection, evaporation and the material's thermal storage. Data from Open-Meteo (forecast, observations, ERA5 reanalysis). For 2030–2100, a 20-year local climatology shifted by AR6 / CMIP6 ensemble deltas under three scenarios. What it refuses to do: hide uncertainty. Every result shows its data type (forecast, observation, reanalysis, projection), its source, an uncertainty range and a confidence index. It is not an official forecast and not a measurement. Try it free, no sign-up: demo on Lille + 3 real estimates → https://thermohelie.neocities.or... Then it's a one-time payment [prix] — no account, no subscription, your data stays on your phone. That single payment funds the professional data access. I'd love your feedback on the physics, on the orders of magnitude, and especially on cases where the result looks wrong — give me the place, hour and material and I'll check. If you own an infrared thermometer, comparisons are very welcome. Thank you!

Thermohélie

Surface temperatures in the sun, anywhere, hour by hour

Surface temperatures in the sun, anywhere, hour by hour