Particular dates which are usually settled or unsettled

[Weather Enthusiast91]

Apologies if this is worded a little poorly, I am terrible at explaining.  

To me, there does seem to be particular dates where the weather is more often than not settled or unsettled. For example, 30th of September is often an unsettled day even during the most anticyclonic of Septembers or autumns, with the last notably settled one being 2015. 11th of September on the other hand more often than not is settled on the most part with the last notably unsettled one occuring in 2017.

26th of November (I remember this one in particular seeing as it's my birthday) these days usually has average daytime temps and is always dull, even during the sunniest of Novembers.

Are there any dates that spring to mind for my fellow weather enthusiasts? 

[Metwatch]

18th June - my birthday has been a washout since 2019, and most of them occuring around or during a thundery outbreak, mostly south east events though like 2019, 2021 and 2022.

This year at last myself seeing a storm, with a shelf cloud in Leicestershire and 20mm back home.

Rainfall totals for the last 5 years on the 18th June here:

2019 3.8mm

2020 13.4mm

2021 11.7mm

2022 12.0mm

2023 20.3mm

Edited September 12, 2023 by Metwatch

[damianslaw]

Early-mid Sept statistically seems to produce more settled days than unsettled ones.

I'd hazard a guess a date in early June tends to be the most settled of the year.

Unsettled days late November or in December. In recent years the days leading up to christmas have been unsettled. 

[B87]

Last 10 days of March are almost always settled and mild to warm. Most of April is settled and dry.

19th July is almost always hot.

First half of September is usually sunny and dry.

The first week of November is usually settled.

Christmas Day is usually cold and sunny.

New Years Eve is always very mild and cloudy. New Years Day is usually sunny.

 

Edited September 13, 2023 by B87

[A Face like Thunder]

I posted somewhere that 10th September was thought to be the most settled day of the year. It seems that 2023 was an exception! 

[Sun Chaser]

Late October always seems to be very wet but in my memory we've had a lot of downpours particularly on the 24th.

On the flip side, we almost always seem to get sunny weather in late February, late March and late May. I would nominate May 27th as being sunny and warm almost every year, even in more unsettled Mays like 2021 and 2022.

[dryfie]

I too have a theory that certain dates bring similar spells of weather and temperature each year.  I’ll publish it once I’ve written The 39 Steps.

[Emz by the Thames]

From memory, not stats, but...

My birthday is July the 18th and I seem to have many birthday evenings sat outside somewhere listening to encroaching thunderstorms while coating myself in aftersun. 18/19 July  just always seem hot and stormy (apart from this year!!)

Second week in October is often calm and sunny.

[Relativistic]

2 hours ago, B87 said:

Christmas Day is usually cold and sunny.

I spend my Christmas Days in Essex and it almost always seems cloudy. Often mild as well.

Edited September 13, 2023 by Relativistic

[B87]

38 minutes ago, Relativistic said:

I spend my Christmas Days in Essex and it almost always seems cloudy. Often mild as well.

They always seem to consist of hazy sunshine and temps of 6-7c here.

[damianslaw]

Halloween and New Years Eve more often than not very mild and wet, Bonfire Night as well.

[Metwatch]

4 hours ago, dryfie said:

I too have a theory that certain dates bring similar spells of weather and temperature each year.  I’ll publish it once I’ve written The 39 Steps.

There's also a similar thing in Spain.

There's the summer of San Miguel where often each year at the end of september it becomes very warm and dry.

Then there is the summer of San Martin where around November 11th often each year there is an anticyclonic and warmer spell for a few days.

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[SunSean]

I have quite a lot of data on this!

The ones that stand out the most-

Feb 13th-18th is a good bet for the first settled sunny spell of the year

March 27th is often sunny

April 18th-22nd is a good bet for sunshine

June 21st-25th is another good shout for sunshine

July 17th-25th is a long stretch that is often sunny

Some of the real bad days-

March 3rd, 4th & 10th all have under 3 hours average sunshine

April 3rd & 28th are the least sunny days in April and the only 2 under 5 hours average

May 8th-11th is the dullest period in May on average

June 12th is the dullest June day on average at 5.3 hours

July 8th is the only day under 5 hours average sun for July, 26th & 27th not much better on 5.2 hours average

August 26th is the dullest day and only one under 5 hours at 4.4

September 27th & 30th are the only 2 in September under 4 hours at 3.7 and 3.3 respectively

October 7th & 14th are the worst 2 in the 1st half of October

November 8th & 27th are real bad at 1.2 hours average only, 24th even worse at 1 hour average

December 21st, Winter solstice is the only day under 1 hour average at 0.9

These stats are based on Heathrow going back to 1989.

[SunSean]

Standout sunny days for Shoeburyness (only goes back to 2016 so a smaller sample but useful for recent trends)

Jan 17th

Feb 25th-27th

March 25th- An impressive 8.2 hours average!

April 17th, 19th, 20th & 21st- All 4 over 8 hours average with the 19th an incredible 10.5 hours average!

May 26th-28th

June 13th-16th, June 22nd is the highest average of the lot at 11.3 hours average!

July 2nd, 5th, 17th, 18th, 23rd- all over 10 hours average

August 6th & 10th

September 7th, 13th & 21st the highest for this month

October 9th

November 2nd, the 18th is good for the latter part of the month

December 4th

Bad ones-

Feb 21st & 22nd

March 1st

April 28th again!

May 2nd & 3rd

June 4th, 12th & 27th

July 27th & 28th

September 30th again!

October 17th

November 15th & 27th

December 7th, 21st & 31st

[Weather Enthusiast91]

37 minutes ago, SunSean said:

I have quite a lot of data on this!

The ones that stand out the most-

Feb 13th-18th is a good bet for the first settled sunny spell of the year

March 27th is often sunny

April 18th-22nd is a good bet for sunshine

June 21st-25th is another good shout for sunshine

July 17th-25th is a long stretch that is often sunny

Some of the real bad days-

March 3rd, 4th & 10th all have under 3 hours average sunshine

April 3rd & 28th are the least sunny days in April and the only 2 under 5 hours average

May 8th-11th is the dullest period in May on average

June 12th is the dullest June day on average at 5.3 hours

July 8th is the only day under 5 hours average sun for July, 26th & 27th not much better on 5.2 hours average

August 26th is the dullest day and only one under 5 hours at 4.4

September 27th & 30th are the only 2 in September under 4 hours at 3.7 and 3.3 respectively

October 7th & 14th are the worst 2 in the 1st half of October

November 8th & 27th are real bad at 1.2 hours average only, 24th even worse at 1 hour average

December 21st, Winter solstice is the only day under 1 hour average at 0.9

These stats are based on Heathrow going back to 1989.

Very informative posts, thanks for sharing.  

[Sun Chaser]

9 hours ago, SunSean said:

April 17th, 19th, 20th & 21st- All 4 over 8 hours average with the 19th an incredible 10.5 hours average!

 

Thinking about this in every April since 2017 we've had a sunny and settled spell coinciding with the particular period April 18th-21st, with 2018 and 2019 being very warm. Even wet ones like this year were good at that point

[A Face like Thunder]

Mrs FLT has a birthday on St Swithin's Day, 15th July, 40 days rain and all that. 2023 joined 2007 in being close to the mark, with rain that day and many days thereafter.

[dryfie]

In the 1800s, Alexander Buchan, Scots Meteorologist, produced lists of warm and cold spells that often applied to Scotland:

Cold 7-14 Feb, 11-14 April,  9-14  May,  29 June - 4 July,  6-11 Aug & 6-13 Nov

Warm 12-15 July,  12-15 Aug & 3-14 Dec

Even allowing for spatial difference, I can't see much alignment with other folks lists.

 

[Weather Enthusiast91]

22nd of September (or thereabouts) is another one. Even during the most anticyclonic of Septembers, the weather around that time is almost always more on the unsettled side. 

[Catbrainz]

Unsettled Christmases are rare here to my memory at least, even during a zonal westerly fest Dec Christmas Eve/Day both tend to be fine days. Late March/Early April also tends to bring a cold snap of some sort (Maybe down to the polar vortex collapsing bringing cold air south). 

[baddie]

I find that June 18th and September 30th are always wet and dull. I think 26th February 25th March, 16th April, 28th May, 10th August, 16th October and 2nd November are always anticyclonic. I feel that every Christmas Day is always overcast, but often dry and settled

I also feel that :
March should always start very dull and overcast, but wall-to-wall sunshine between the 23rd and 27th
The last few days of April should always be dull, cool and wet, while the rest of the month is warm and sunny
The hottest day of the year should always be around the 15th-20th July
August to always follow the same theme as this years, but with hotter temepratures around the 10th
Ocotber should always start unsettled, then anticyclonic for two weeks, followed by a stormy end
November should be like Feb 2019 in the first 10 days, with an unsettled middle and a cold end
 

On 13/09/2023 at 23:00, SunSean said:

Standout sunny days for Shoeburyness (only goes back to 2016 so a smaller sample but useful for recent trends)

Jan 17th

Feb 25th-27th

March 25th- An impressive 8.2 hours average!

April 17th, 19th, 20th & 21st- All 4 over 8 hours average with the 19th an incredible 10.5 hours average!

May 26th-28th

June 13th-16th, June 22nd is the highest average of the lot at 11.3 hours average!

July 2nd, 5th, 17th, 18th, 23rd- all over 10 hours average

August 6th & 10th

September 7th, 13th & 21st the highest for this month

October 9th

November 2nd, the 18th is good for the latter part of the month

December 4th

Bad ones-

Feb 21st & 22nd

March 1st

April 28th again!

May 2nd & 3rd

June 4th, 12th & 27th

July 27th & 28th

September 30th again!

October 17th

November 15th & 27th

December 7th, 21st & 31st

Add June 18th to that list, it was very wet for the past 5 years

[SunSean]

1 hour ago, baddie said:

I find that June 18th and September 30th are always wet and dull. I think 26th February 25th March, 16th April, 28th May, 10th August, 16th October and 2nd November are always anticyclonic. I feel that every Christmas Day is always overcast, but often dry and settled

I also feel that :
March should always start very dull and overcast, but wall-to-wall sunshine between the 23rd and 27th
The last few days of April should always be dull, cool and wet, while the rest of the month is warm and sunny
The hottest day of the year should always be around the 15th-20th July
August to always follow the same theme as this years, but with hotter temepratures around the 10th
Ocotber should always start unsettled, then anticyclonic for two weeks, followed by a stormy end
November should be like Feb 2019 in the first 10 days, with an unsettled middle and a cold end
 

Add June 18th to that list, it was very wet for the past 5 years

Yes, June 18th and also 17th are pretty bad along with the last 4 days of June also and the 5th along with the ones I already mentioned. Don't know why I missed those out, must have been skimming!

[baddie]

28 minutes ago, SunSean said:

Yes, June 18th and also 17th are pretty bad along with the last 4 days of June also and the 5th along with the ones I already mentioned. Don't know why I missed those out, must have been skimming!

I disagree about June 17th, as this years was warm and dry, with that weird hazy sunshine. Last years June 17th was actually hot and sunny, reaching 30c. Every 27th-30th June since 2020 was often dull and showery. The same goes for every end to April, which is always dull and showery, and it was a theme since 2012. The first 5 days of March are also dull and drizzly, as in the past 3 years, I recorded no sunshine until the 6th or 7th. March 2011 and 2018 also started very dull.

I often get lucky on my birthday (March 25th), as on every year since 2015, most of them recorded wall-to-wall sunshine, or at least partly cloudy

Edited September 17, 2023 by baddie

[SunSean]

29 minutes ago, baddie said:

I disagree about June 17th, as this years was warm and dry, with that weird hazy sunshine. Last years June 17th was actually hot and sunny, reaching 30c. Every 27th-30th June since 2020 was often dull and showery. The same goes for every end to April, which is always dull and showery, and it was a theme since 2012. The first 5 days of March are also dull and drizzly, as in the past 3 years, I recorded no sunshine until the 6th or 7th. March 2011 and 2018 also started very dull.

I often get lucky on my birthday (March 25th), as on every year since 2015, most of them recorded wall-to-wall sunshine, or at least partly cloudy

The average sun per day for June 17th at Shoebury is only 5.3 hours. Not great but 3 of the 8 days since 2016 were pretty much wall to wall sunshine, it's pegged back by 4 atrocious days of under 2 hours sun recorded. Maybe we will get a sunny one again next year. Agree on the rest though. Its strange that the end of April is always pants, even in the best April's! 25th March is indeed a good bet for a decent day.

[baddie]

3 hours ago, SunSean said:

The average sun per day for June 17th at Shoebury is only 5.3 hours. Not great but 3 of the 8 days since 2016 were pretty much wall to wall sunshine, it's pegged back by 4 atrocious days of under 2 hours sun recorded. Maybe we will get a sunny one again next year. Agree on the rest though. Its strange that the end of April is always pants, even in the best April's! 25th March is indeed a good bet for a decent day.

If you want wall-to-wall sunshine between the 1st-5th March or 26th-30th April or 1st-5th October, your unlucky.

Edited September 17, 2023 by baddie