Hi All,

I'm a long time lurker who is just interested in the weather, but possibly
more so than your 'average Joe' which is why I enjoy reading all the
interesting stuff from the experts on here. I like to think I've developed a
better understanding of forecasting as a result of lurking here but there's
one thing that puzzles me and would really appreciate some guidance from the
contributors to this group.

One of the sites I regularly look at gives an 3 hour forecast window
including a UV index and this always peaks between 16.00 and 19.00 when, for
example, today and tomorrow (Sunday and Monday) it shows the UV level as 8
during these hours but only 6 between 13.00 and 15.59. I can't fathom out
why this should be - surely the UV index would peak when the sun is
strongest which, in summer time in the UK would be around lunchtime,
wouldn't it? Please bear in mind I'm a complete novice and have no detailed
understanding of weather systems and suchlike but info I've read on this
group has helped me understand a good deal over the last couple of years;
but I just can't understand why the UV level isn't strongest when you'd
expect the sunshine (when we get it) to be strongest.

Thanks

Mike.