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About this tool
Find the comparatively lower-UV windows for going outdoors from the forecast.
UV Safety Window pulls the hourly UV index forecast for a set of coordinates from the Open-Meteo forecast API and lists only the hours where the UV index is 2 or below — the WHO 'Low' exposure band — across the next three days. Each row shows the local hour, the forecast UV index and the clear-sky UV index for the same hour, so you can see how much of the low reading depends on expected cloud cover. It is for people planning outdoor time around sun exposure who would rather read the actual hourly forecast than guess from the time of day.
Open UV Safety Window on AltFTool — it loads instantly in your browser.
Enter Latitude and Longitude, or press Use device location to fill both from the browser.
Press Get current result to query the Open-Meteo forecast API for hourly uv_index and uv_index_clear_sky over a 3-day window.
Current result lists up to 48 forecast hours at UV index 2 or below, each row giving the local hour, the forecast UV and the clear-sky UV, with the fetch timestamp and source below.
Rather than a full 72-hour UV curve to interpret, it returns only the qualifying hours — up to 48 of them — so the answer is a list of times, not a graph.
When the forecast UV is low but the clear-sky figure for the same hour is high, the low reading is coming from expected cloud, which can break before you go out.
You can type a latitude and longitude or take them from the device, and the API returns times in the local timezone for that point, not yours.
This tool uses the WHO 'Low' band, UV index 0–2, as its threshold. The standard bands are 0–2 low, 3–5 moderate, 6–7 high, 8–10 very high and 11+ extreme; sun protection is generally advised from 3 upwards, though low does not mean no risk.
Three days. It requests hourly uv_index and uv_index_clear_sky for a 3-day forecast window and lists the first 48 hours that meet the threshold, so a period of persistently high UV can return few rows or none.
Because the index describes the forecast intensity, not your personal risk. Skin type, medication, altitude, reflection off snow, water or sand, and how long you stay out all change how much exposure you accumulate — treat this as informational and speak to a doctor or dermatologist about your own protection needs.
The Open-Meteo forecast API, queried live with your coordinates and timezone=auto. Each result is stamped with the time it was fetched, and coverage, refresh frequency and accuracy are whatever that provider offers.