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If you get less than 50% possible sunshine in the sunniest month, which London and the majority of the country does get, then it's obviously more than partly cloudy.
1) Heathrow's sunshine record is not the WMO standard.
2) The recorder seems to ignore more sunshine than it should around sunrise and sunset. 3-4 hrs on a few of the days last week. This doesn't seem to happen even in the high latitude climates.
The Heathrow overall averages seem to fit into the regional pattern OK. I'd have to know whether or not they are using electronic recording or older Campbell-Stokes type of manual recording, which can't usually respond to the lowest 30 minutes of sun angles. Or there could be horizon obstructions. You could ask UK Met. how much sunshine gets recorded on the clearest days at other sites around London and the SE zone. No doubt they would charge you if any data was provided - our gov't met. agencies were doing that for a number of years but the government here stopped that nonsense back in 2007.
Heathrow switched to KZ in 2005. They have been adjusting the hours since then (taking hours off) to fit in with the old CS data.
The CS in Kew Gardens has a burn threshold of about 140W/m2, compared to the 120W/m2 WMO standard. If the Met Office did not adjust the figures, then winter hours would be around 5-10% higher, and summer around 10-15% higher.
1) Heathrow's sunshine record is not the WMO standard.
2) The recorder seems to ignore more sunshine than it should around sunrise and sunset. 3-4 hrs on a few of the days last week. This doesn't seem to happen even in the high latitude climates.
The Kew data shows a peak average of about 48% in August. This is after deducting 30 minutes per day from astronomical day-lengths. The sunniest "mainland" locations do somewhat better (as one would hope) with Shanklin and Bognor both peaking at about 55% under the same assumptions.
The Kew data shows a peak average of about 48% in August. This is after deducting 30 minutes per day from astronomical day-lengths. The sunniest "mainland" locations do somewhat better (as one would hope) with Shanklin and Bognor both peaking at about 55% under the same assumptions.
Assuming the raw KZ data gives sunshine figures around 12-13% higher than CS in summer (from what I have measured on the historic data page) you get around 51% in July and 53% in August.
Assuming the raw KZ data gives sunshine figures around 12-13% higher than CS in summer (from what I have measured on the historic data page) you get around 51% in July and 53% in August.
Sounds about right. The problem I have with KZ is that a fixed threshold of intensity is used: ‘the duration of the period for which the direct solar irradiance exceeds 120 W/m²’. For me, in temperate latitudes "bright sunshine" in winter is not the same thing as "bright sunshine" in summer, and I suspect that for records taken in this country that either the setting is too tolerant of weakish summer sunshine, and/or some non-direct radiation is getting logged for whatever reason.
I find the UK Met to be quite useless in general. Their station coverage is woeful. No station for a city rapidly approaching 1 million people. Simple data is also pay-only so no useful websites like NOAA/NWS have.
Even though I now live in Malta, where it is hot & sunny for months on end, I still don't think the UK has dreadful summers... Maybe it's because where I'm from is within the sunniest part of the UK, but the summers there were perfectly adequate for me most of the time. Ok you may get the odd iffy day & some summers may have more rain than others, but in general it is warm enough to be in T-shirt & shorts most of the time, it is warm enough to do stuff outdoors & have BBQ's etc.. And at least it isn't too hot to be able to be outside & do various activities & go about day to day life... Here it gets too hot & it is awful traveling about to work, going to shops etc.. when it is so hot & humid that you are dripping with sweat & feel like you are going to collapse with heat stroke just from carrying a few bags of shopping home!
Hotter climates are great for holidays, but quite different when you actually live in one
I agree with Dean. The UK in general has a **** climate. Low 70F highs in summer are pus and not warm at all. Should be the overnight low. All of the UK has defective summers in my opinion, in summer I want to feel genuine heat. All of the UK is far too cloudy aswell, 1600 hours of sun in London, seriously **** that. That is cloudy as **** I dont care what anyone says. And that is at the higher end of the UK scale.
Places like Liverpool and Leeds have astonishingly crap climates. Extremely cloudy with no summers at all.
Sunmer may be fine for outdoor activities, but it is not a genuine summer. And the rest of the year is retardedly gloomy, clammy and miserably cool.
My definition of summer, is the warmest part of the year. Summer in the UK is certainly distinguishable from the other 3 seasons. Every temperate climate, has a summer, and a winter. You can say that the UK has a cool summer or a cloudy summer, but to say it has no summer, is pretty silly. I think winters in Melbourne, for example, are very mild, but they certainly exist - at least, you seemed to think they did, despite snow being almost completely absent from Melbourne's history.
Personally, I value comfort, more than heat for the sake of it. I think low 20s/low 70s, is ideal for outdoor recreation - certainly, a leisurely bike ride is preferable at 23C than at 33C, at least to me. 33C would have higher evening temperatures, so better for a 10pm BBQ or outdoor terrace party in the early hours of the morning. I ask this question sincerely - does anyone on here, find 33C more comfortable, than 23C, given sunny conditions and little wind? I didn't find 33C to be too bad, but certainly not as nice as 23C with similar conditions. The best thing to do on a 33C day, is nothing at all.
It's nice to hear insight from flamingGalah though - a person currently residing in a hot-summer climate after relocating from a 'dreadful' summer climate. I can certainly see his point of view - Maltese summers do not look pleasant at all. The dry summer heat of interior Spain would be more tolerable, than the high-humidity sauna of Malta in July and August.
Either way, I'm not here to make people like British summers. People should just bear in mind that on a typical summer day, you don't hear people complaining about how dreadful the weather is. I think most would prefer warmer, sunnier summers (even B87 would as his ideal climate clearly shows), just that, summers here really aren't the abominations some seem to think. If it rained most days, I'd understand, but the weather is largely inoffensive, to the point where you don't even notice it.
I mean, even myself would value more summer sun, but it's not so cloudy that I'm depressed or irritable. Most days have some sunshine, and even the cloudier days are at least bright. As B87 mentioned, stratus is uncommon in summer - cloudy summer days are convective in nature.
Last edited by dunno what to put here; 05-20-2016 at 05:54 PM..
Heathrow switched to KZ in 2005. They have been adjusting the hours since then (taking hours off) to fit in with the old CS data.
The CS in Kew Gardens has a burn threshold of about 140W/m2, compared to the 120W/m2 WMO standard. If the Met Office did not adjust the figures, then winter hours would be around 5-10% higher, and summer around 10-15% higher.
Over here there has been no attempt to "back-fit" the data. Most stations are now using KZ but meanwhile record highs are being regularly "set" because the 30-year means are based on CS data. Until the conversion is complete inter-site comparisons are not necessarily valid and of course assessment of deviations form means is near to "meaningless".
YEAH, A FIGHT!!!! Too bad I missed it and some posts were deleted.
ROUND TWO PLZ???!!!
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Simple data is also pay-only so no useful websites like NOAA/NWS have.
