The UK has for a long time been described has having a maximum UV index of 8, at one location in Cornwall, rarely. This was challenged at the MetO in recent years until they adjusted their forecast UV range from 1-7 to 1-8. A factor of 8 is now more commonly forecast eg on the BBC website in June & July.

This interesting link gives a UV reading in Reading in June 2000 (this was, admittedly, a notable dry air high UV event) of about 9.6. Reading is some distance inland away from the S coast where higher UV indices are often recorded.There are other events I am sure if anyone has the time to scroll through the site.

On that June day I was walking north in the Wallop Brook valley and had my shirt off for about 15 minutes before my wife told me to put it back on. I have a white skin that tans easily. I burned. I just thought the UV index was a worthwhile topic- some of us look out for it cranking up to 2 in March each year with some excitement!

https://uk-air.defra.gov.uk/data/uv-index-graphs

 

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Forgot to add- notice on some days the curve is constant, but these are not the days with the highest UV- the spikier days, suggesting cumulus or other interruptions, reach the highest values; cloud cover or air type intensifying the UV?

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Good website that. It gives a good visualisation of UV indices in the UK. It's a website I might use more often.

I wonder if these very high UV indices can be attributed to decreased ozone in the stratosphere. If you get an area of atmosphere with a lower concentration of stratospheric ozone over a region near the summer solstice (or at any time of year, in fact), it is bound to result in a higher index.

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some of us look out for it cranking up to 2 in March each year with some excitement!

https://uk-air.defra.gov.uk/data/uv-index-graphs

 

As the proud owner of my own little green power station - my 15 panel  solar array - I notice how the solar output ticks up markedly under any sun at the very start of March, compared to a week or two beforehand.  Exciting times, I relish this time of year, the best of the astronomical winter just about to come, and the promise of increasing daylength and some sparkling sunshine just around the corner. 

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Good website that. 

March 7th is the day when the sun starts to turn my skin a healthier looking colour. Tanning opportunity continues until about 2nd October down here for me. By mid January I start to look decidedly pale !

Between 7-14th March the sun really does ramp up.

Not long now...

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Good website that. 

March 7th is the day when the sun starts to turn my skin a healthier looking colour. Tanning opportunity continues until about 2nd October down here for me. By mid January I start to look decidedly pale !

Between 7-14th March the sun really does ramp up.

Not long now...

I agree- at least, in our sort of latitude; I do remember a slight bronzing (you'd have to want to see it, if you know what I mean) out on Purbeck in Feb 87, under long periods of sun, but my earliest gentle tanning recently was first week of March, re-roofing the shed. The shadow of the house down the lawn shortens quickly through March too.

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http://www.bbc.co.uk/weather/2633858

First UV2 forecast for the Itchen Valley today. That'll open the crocuses.

Just seen yesterday's data- it did just reach 2 at around 1200 but sadly I was locked away in a dark box.

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UV max at Reading 1.7 on Saturday and 1.6 yesterday despite the cloud.

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Reading max UV 2.1 yesterday; highest of the year so far.

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UV 1.6 max at Reading yesterday.

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Reading UV yesterday 1.4 max.

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I notice this also because of my PV panels. The last few days the peak output has been rising, and today was reaching 2.8kwh for a time.
Not long until I get the battery system installed with another 1.5 kw on garage roof, and will be electrically self sufficient for 9 months of the year.

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Reading UV max 1.8 yesterday. Already 1.3 at 9am this morning.

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Above 2 is the threshold I look for, because it's only above that number that exposure to UV enables the body to start generating vitamin D.

 

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Peaked at 1.9 today. Thought it could have passed two easily.

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Got a peak of 1.6 on my PWS. It is creeping up.

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It's certainly creeping up... another three weeks or so and it'll be a case of having to slop on loads of oily goop when I go on wolf walks. Roll on October!

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A few extra minutes of solar heating in my famed west-facing hobby room this afternoon.  That's a few less minutes saved on the central heating. Of course, that only applies when the sun is actually out, like it has been off and on today.

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Only managed 1.3 today under extensive cloud- but that in itself is interesting, as Boxing Day was a beautiful sunny morning and it only reached 1.3 in the sunshine- so UV levels under the cloud now match those in bright sunshine near the solstice.

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Reached 1.8 at 11a.m. before the weather turned for the day. Another week and we'll be seeing 2.5, I'm sure. Interesting that the Beeb/ MetO seem to be quite frequently forecasting 2s for the south earlier in the year than usual.

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