Today's UV index at Uccle
The graph shows the forecasted and measured UV index at Uccle for today. The forecast is based on a model with the ephemerides and the ozone column as main input parameters. The observations (made each half hour) are performed with a Brewer spectrophotometer at RMIB. The actual values of the UV index at other sites in the country can deviate significantly from those at Uccle, mainly due to differences in the cloud cover which can attenuate the UV radiation of about 80%. The forecasted value is always for clear-sky conditions. At (heavy) cloud cover the measured values are necessary (much) lower than the forecasted ones.
Information about the definition and interpretation of the UV-index can be found in the section UV-index Definition
Our colleagues of the Belgian Institute for Space Aeronomy (BIRA-IASB) perform additional measurements of the UV index with broadband instruments at other locations in Belgium.