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1.4 today.
Hope you don't mind me hijacking this thread as it is an interesting read! It prompted me look at my own UV indices here in Santa Monica:http://www.homefacts.com/uvindex/California/Los-Angeles-County/Santa-Monica.htmlThe highest it goes in December is 4, average in the 2's. In June and July it gets as high as 12, with averages in the 11's.Today is currently 2.87 under think cloud. Should be a little over 5 later in the week under clear skies. By mid-March, it can already be as high as 8!Interestingly, my skin has gotten used to it and I don't burn anywhere near as fast as I used to, and this is coming from a fair-skinned Yorkshireman.
Glad you could join the thread Lumi!
It will be interesting to compare the Santa Monica/ various UK locations as the year progresses. I'd like to draw your attention to the day in June 2000 when phenomenally dry air gave a level in Reading of > 9. Some UK spots may have approached 10 that day. The previous forecast range of 1-7 for the UK (which, after my contestations with the metO was upped to 😎 were clearly related to general data, rather than extreme. I bet Santa M gets a 14 on the most extreme!
8 is a regular June/ July forecast in S. UK now. 6 from May to August is common.
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?
Generally days with lower upper air humidity (like today!) are the days with deep blue skies and puffy cumulus clouds, so the UV reading between clouds will be higher.
Hazy summer days with higher humidity and a bit of general high cirrus tend to have fewer cumulus clouds.
This is a good link showing current and forecast upper air humidity. Dark browns (low humidity) are usually associated with deep blue skies (assuming there is no lower level cloud obscuring it of course!)
http://www.instantweathermaps.com/GFS-php/showmap-euroupper.php?run=2017022806&var=RH&lev=300mb&hour=000
1.7 today.
Generally days with lower upper air humidity (like today!) are the days with deep blue skies and puffy cumulus clouds, so the UV reading between clouds will be higher.Hazy summer days with higher humidity and a bit of general high cirrus tend to have fewer cumulus clouds. This is a good link showing current and forecast upper air humidity. Dark browns (low humidity) are usually associated with deep blue skies (assuming there is no lower level cloud obscuring it of course!) http://www.instantweathermaps.com/GFS-php/showmap-euroupper.php?run=2017022806&var=RH&lev=300mb&hour=000
Thanks for the link Rob; what you say certainly makes sense. I can correlate the RH (roughly) from your link on different days with the max UV, other factors considered (I might try on April-Sep days, say, with 10 hours + sunshine just to create a weak control measure).
Manchester is pretty much seeing daytime UV indices of 2 now. I usually find that the first moderate UV is around mid-March here.Last year, I think it first happened on March 11.
Interesting. The 2s have come early this year too. Those quoted are for Reading- we are some way south of Reading, so mid Feb is possible.
Just under, but rounded to, 2 today.
Cracking day here. Currently 20c, humidity 30% and UV of 5.
That'll get your plants going. Still on for a 6 tomorrow?
I haven't checked but definitely a 6 still in the forecast for Friday. Didn't get my seeds in yesterday as composting, feeding and watering all the potted fruit trees/shrubs took a lot longer than expected. The sun still sets about 5.45pm here so not much time to do anything after work. Will attempt to get them in today to take advantage of the 24c weather and high UV forecast over the next couple of days.
I probably should really be contributing to the gardening thread.
2.2 today- best so far.
1.8 today- cloudy
UV of 6 today under slightly hazy skies. 25c and humidity of 10% whilst writing.
Currently 1.9 with the sun popping in and out behind the clouds. Could we top this year's best- a 2.3? Doesn't compare to Lummi's, of course.
Actually only reached 2.0 yesterday, as cloud and in-forecasted rain spoiled the afternoon. Looking out of the window right now, it's hard to believe that 2 is also forecast for today.
2.1 yesterday. 2.3 today- today holds the top spot.
2.5 today. Thought it felt a bit special in the few moments around 1pm when I got out. In fact the chart for Reading shows 2.5 from about 1130a.m. to 1p.m. Good clear air after the rain.