Feels-like temperature, wind and the UV index

Thursday, 15 October · Zefita

Feels-like temperature combines air temperature with wind, humidity and sunshine. In winter a 40 km/h wind makes −5 °C feel like −12 °C (wind chill). In summer 80 % humidity makes 32 °C feel like 38 °C. Dress for “feels like”, not for the thermometer.

Wind is given as the average speed at 10 m height; gusts are the peaks lasting a few seconds. Gusts above 60 km/h break branches and topple light objects; above 90 km/h they are dangerous for drivers and roofs. National services usually issue warnings from 70–80 km/h.

The UV index measures the strength of ultraviolet radiation at midday: 1–2 low, 3–5 moderate, 6–7 high, 8–10 very high, 11+ extreme. From 3 upwards you need protection (shade, hat, sunscreen). Thin clouds reduce UV only slightly; snow and water amplify it.

Chance of precipitation (e.g. 40 %) means that in similar conditions it rained in 4 out of 10 cases at that point — not that it will rain for 40 % of the day.