Actual readings for today. Click on graphic to view a large version.

Find out more about the UV-Index

Examples of mid-day solar spectra measured with the SERC SR-18 spectroradiometer showing variations in the UVB spectrum

Measurements at Edgewater, MD around the summer solstice (June) and winter solstice (December). At the lower sun angle in December results show there is a stronger reduction at the shorter ( <305 nm) compared to the longer wavelengths.

Measurements at Palmer Station, Antarctica: November 1997, showing the greater enhancement of short wavelengths caused by the presence of the ozone hole (150 D.U.) compared to "normal" ozone (300 D.U.)