Sunshine Level Watch 2024

[Terminal Moraine]

55.0 hrs of sunshine here in the first 24 days of April, 56% of average.  It's still possible it could be the dullest April on record ( since 2000) as April 2000 recorded 75.5 hrs and currently holds the record.

[richie3846]

113.6 hours sunshine at Brize Norton, my nearest met office site. I'm assuming the weatheronline.co.uk figures are raw data. If so that'll be around 124 hours of adjusted figures. With 6 days left, it seems likely that we'll end up being only slightly below average, quite a turnaround from the opening week.

The middle two weeks were quite sunny, more than average, so overall the month has felt quite reasonable here.

So 365 hours this year so far. It appears we've not been as cloudy locally compared with some other areas. 

Thanks to B87 for providing the adjustment table. I'll use that from now on, I've saved a screenshot for future reference. Worth mentioning that when we're looking at sunshine folks, it may be useful to find out, or try and work out if the data source is raw or adjusted. I'm getting a vibe that sometimes people are looking at the raw data, and therefore believing it's cloudier than it is compared to average. I worked out that weatheronline.co.uk uses raw data, because their numbers don't match the met office climate summaries. 

[SunSean]

 richie3846 Heathrow's adjusted values don't represent every station though so you have to be careful. Heathrow & Charlwood are underestimating sunshine figures by quite a bit but other locations such as Manston, Brize Norton etc probably only underestimate by a tiny fraction. The easiest way to figure how much of a deficit at certain stations, for me at least (and even that isn't 100% accurate) is to check values on the ensoleillement map on Meteociel when there has been wall to wall sunshine, particularly in Summer months & you can see which places are worse than others for sunshine reporting. Herstmonceux is by far the worst reporter as they only record something silly, like 11.6 hours of sun on a perfectly clear day, while Heathrow & Charlwood would get about 14.2, Shoeburyness 14.7 max & places like Manston, Brize Norton 15.1.

It's way more complicated & very annoying that stations don't adjust themselves! I try to keep it as fair as I can in my sunshine tables by not adjusting the ones that only need miniscule adjustments & then adjusting a bit less than necessary, other stations like Heathrow & Charlwood & it seems to more or less work out about right- but still not 100% accurate of course!

[SunSean]

This will be the first April in Shoeburyness history to not record a single day with 10+ hours sunshine. Satanic.

[SunSean]

Looks like one of the stations I've been using for my England county sunshine tables have stopped recording data! 

Wittering- No data since April 22nd...

I wonder why? Is it a glitch & they are working on a fix or do I have to look elsewhere for a new station in that region?

[Terminal Moraine]

Despite the sunniest day of the year so far yesterday, with 10.3 hrs, April was still the dullest on record here ( since 2000)  with 73.7 hrs of sunshine, 61% of average. Previously the dullest was 2000 with 75.5 hrs.

[In Absence of True Seasons]

 Terminal Moraine Unsurprising.

I think London scraped by with about 70% of average sunshine in the end but a big part of that is as a result of these last 2 days which recorded 10 hours of sun. 

A very dull month all around, like most of the months in the last 12, lol (aside from Sept and June 2023 ofc).

[SunSean]

(Posted in wrong thread previously)

Now that April 2024 has finished, I have the stats to show just how BAD this month was, in terms of sunshine...

Shoeburyness-

Average number of sunny days (50%+ sunshine) is 13 and this gets achieved almost every year- April 2016 (13) April 2017 (12) April 2018 (13) April 2019 (14) April 2020 (19) April 2021 (17) April 2022 (14)

April 2023 managed the lowest ever total of just 8 and I didn't expect to see a number this low again but April 2024 came along and shouted, "hold my beer!" April 2024 managed just 5 days. 5!!!!!!! Absolute bottom of the barrel stuff!! The average number of 50%+ days for December & January is 8 for crying out loud...

Added to this that February 2024 managed only 4 days out of 29 with 50%+ and March 2024 managed also a pathetic 4 out of 31 and we stand at 13 days of 50%+ sunshine out of the last 91 days. Pathetic. Absolutely pathetic. This is the lowest number of sunny days from the Feb to Apr period on record for Shoeburyness. The next lowest is 2023 funnily enough, with a rubbish 22 days. 2024 is THAT much worse than 2023 already!

But wait...there's more...

April 2024 was in fact, so bad here, that it is now the new worst month ever in the April to September period in terms of proportional sunshine! Yay!! What a time to be alive! It used to be July 2023, 2nd to last with 32.2% of available sunshine achieved & bottom was the dreadful June 2016 with 29.9% of available sunshine achieved but April 2024? 29.7% of available sunshine achieved- A new absolute low, dethroning June 2016.

124 hours of sunshine in April is basically a bang average, nothing to note March but to get this figure when the days are supposedly getting brighter & the evenings longer, is a massive blow. April is normally one of my favourite months but it has been getting worse & worse every year now unfortunately, culminating in the new "dullest month ever!" in 2024!

One thing I worry about as I wake up to yet another dreary gloom filled "October" morning, thinking it can't get any duller... Will May 2024 once again shout "Hold my beer!!!"? Looking at the forecasts & horrific model outputs...I think my fears will be confirmed.

All that's left is hope, that the weather gods will finally shine their light on us after one of the dullest era's in living memory. 

[SunSean]

April 2024 🌧

[*Stormforce~beka*]

We did very well here!

[B87]

137.7 hours for London in the end. Pretty terrible for April!

[baddie]

 SunSean April 2024 was poor, but not as dire as you make it out to be. You must have not experienced April 2012, which is miles worse than this April. April 2018 was also utterly dire (Worse than 2012) outside of that hot spell mid-month

In my area, the sunniest day in April 2008 was a measly 7.5 hours 

Edited Wednesday at 22:31 by baddie

[danm]

Got this from the Met Office when querying why their anomaly maps show the corrected sunshine totals, but the number totals listed against each station are the lower, raw figures:

There are two types of sensor the Kipp & Zonen and the Campbell Stokes. The Heathrow measurements switched from Campbell Stokes (an older style of instrument) to the newer Kipp & Zonen instrument in September 2005. After the switch the new measurements are adjusted to match the old, to give us a consistent measurement across the UK and a homogeneous time series for that station.

The adjustment we use for these monthly data can be explained in an a published paper describing the problem and a similar adjustment (but NOT the one we use) which could be applied to daily data. You can find that here: https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2288. We don't use this one because we don't grid the daily sunshine data, only the monthly.

The newer instrument is adjusted to match the earlier one, to keep the UK measurements and the timeseries consistent. We list the observed, unadjusted data in the station files, but we map the adjusted data, because the network is a mixture of both sensor types (the key which describes which sensor is used for each measurement is at the top of the file, Kipp & Zonnen is marked with a #).

[B87]

 danm I think Reading University used both instruments in the same place, and the KZ there always records higher values than the CS instrument. It seems to be completely random whether the KZ or CS records more at a particular location, but some places have started recording wild values since switching to KZ (eg Warsaw, which has gone from 1570 hours during 81-10 to 1900 hours for 91-20).

Monthly weather summary for Reading, UK, weather

WWW.MET.READING.AC.UK

---

University of Reading past weather

 

[danm]

 B87 that’s interesting. From what I’ve read, apparently the CS instrument overestimates sunshine in hazy or broken cloud conditions, which is why the KZ readings are adjusted up to match the old CS readings.

[SunSean]

 baddie Don't remember April 2012 but for my area, Shoeburyness, April 2018 was FAR better than 2024. We recorded 150 hours of sun in April 2018, which isn't much but better than the measly 124 we got this year. Plus in April 2018, from the 14th to the 26th, we had 11 out of 13 days with over 7 hours sunshine, most days around the 10 hour mark or above along with very warm temperatures. That spell alone was so great, that despite April 2018 finishing on a low figure overall, is a month I still remember more fondly and was 1000 times better than anything we got in April 2024 or even 2023 for that fact. Perhaps it was rubbish the whole way through in your area, Nottingham though.

[B87]

 danmThe KZ sensor at Reading seems to regularly record more sunshine than the CS does though. Warsaw at 1900 hours of sun vs 1570 on the old CS seems completely inaccurate.

 

[danm]

 B87 I'd replied to the Met Office after they sent me the above about whether the old CS sensors slightly over-estimate the amount of sunshine. This is the reply I got this morning:

Thank you for your patience; we have received the below response from the relevant team;

"It is likely (as described in Legg 2014 Comparison of daily sunshine duration recorded by Campbell-Stokes and Kipp and Zonen sensors - Legg - 2014 - Weather - Wiley Online Library<https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2288>) that the earlier Campbell- Stokes sensor slightly overestimates the number of hours of sunshine measured. However, to ensure consistency in the long term series, adjustments are made to match the new observations type to the existing data. This allows the series to continue with good homogeneity allowing us to assess trends and long term changes."

Further details can be found within the paper itself. 

[B87]

 danm That doesn't account for places like Reading and Warsaw recording more with the KZ than the CS. Warsaw averaging an extra 400 hours seems highly suspect.

[danm]

 B87 don't know about those sites. Could be some other factor maybe? 

From what i've read the CS sensors over estimate sunshine a little in hazy or broken cloud set ups. 

https://www.researchgate.net/publication/230346161_Comparison_of_sunshine_recorded_by_Campbell-Stokes_and_automatic_sensors

The differences were both positive and negative with no pattern of occurrences. Comparing CS and CSD1 in England, Kerr and Tabony [24] found that the CS recorder overestimates the sunshine due to the spreading of the burn on the card. This occurs in cases when cloud cover is broken, and the sun is high in the sky.

[damianslaw]

 SunSean Shap bottom, abysmal month for sunshine here. 

[SunSean]

After 3 days of May 2024-

Stornoway in NW Scotland- 36 hours of sunshine

London Heathrow in SE England- 1 hour of sunshine

LOL.

Oh the days when the South East was the sunniest place in the UK, how I miss them! 

I don't believe places in NW Scotland SHOULD be sunnier than places in the South East between March & June, it just seems to be an incredibly unusual phenomena of late that has occurred for a few years now. It would be like NW France being sunnier than the South of France! I'm blaming the SSW crap.

[dryfie]

The NW Scotland effect is by no means a modern phenomenon. I stand to be corrected, but my memory from training school back in the 70’s was that spring in Scotland was the only period anywhere in the UK that the prevailing wind was not SW’ly, but SE’ly.  A more recent tendency is so many people pretending to forecast for the nation without having a clue about the climate here.

[SunSean]

 dryfie You are correct, I don't know too much about Scottish weather, I just find it hard to wrap my head around the fact that parts of Scotland are sunnier than South East England between March & June! Although when I think about it a bit deeper, places in Finland & Denmark also get more sun than us at times so I shouldn't be too surprised. I guess it's a stereotype that Scotland is dull year round. July & August are quite dull up there though in comparison?