Heatwave 22-27 June - effect on the UK Railway

[duffield]

A lot of the weather models are firming up on something exceptional and potentially record breaking. The reason being high pressure being trapped over the UK, with increasingly dry soil conditions, exacerbating temperatures.

Should it get anywhere near what is being predicted, then widespread disruption and even some sort of suspension is possible, given what we’ve seen with this heatwave, which had lower max temperatures.

Lots of posts on social media are now surfacing - take this one for example.

I’d suggest fuelling internet hysteria based on 12 day-out weather models isn’t a good use of anyone’s time.

Yes, it's predicting 41C for the Birmingham area on 11th July. Meanwhile the BBC has the peak temperature at 30C for the same day. At least one of these is going to be wildly inaccurate!

 

[WillC]

Yes, it's predicting 41C for the Birmingham area on 11th July. Meanwhile the BBC has the peak temperature at 30C for the same day. At least one of these is going to be wildly inaccurate!

My point is that no weather model is worth talking about 12 days out. If you read the MetO summary for this period it makes general, qualified suggestions with comments of likelihood. Apps that show detail for D+10 days in the same way they do for D+3 are largely useless and give a completely false sense of accuracy. Also, the trashy media lovely a scary weather model image with lots of frightening-looking purple colours. It’s basically click bait.

 

[mikeb42]

If you're going to pay any attention to model output at this distance (unwise, other than e.g. to raise risk awareness for the likes of contingency planners) the very least you need to do is look at something like this:

ECMWF Scatter for London 2m Temps, 50 model runs + average + operational

This at least gives you a quantitative view of the (un)reliability of the model output - as effectively revealed by itself*. You then have a rational basis on how much value to place on e.g. predictions of 40º maxima.

At the time of writing these are the extreme outliers at a point where the output has a particularly large standard deviation.

A reasonable probability of a warm phase around the 10th is what that lot actually distills down to right now.

Of course it could be 40º+ by then, but the world  could also have been demolished to make way for a hyperspace bypass in the interim...

*That's before you even open the can of worms of the veracity of anything the models churn out at that distance. The retrospective correlations with what actually happens in reality suggest that at the far end of the timeframe they are useful to the extent of being just about measurably better than tossing a coin or consulting a soothsayer.

 

[IlkleyRunner]

I see someone has found a wxcharts forecast. The same people who predict blizzards endlessly every winter. The Reach stable of papers in particular seem very fond of them...

 

[Darandio]

I see someone has found a wxcharts forecast. The same people who predict blizzards endlessly every winter. The Reach stable of papers in particular seem very fond of them...

Reach could cherry pick future output from any manner of other similar model aggregator sites. It's not WX that you need to be mad at here.

 

[Russel]

Reach could cherry pick future output from any manner of other similar model aggregator sites. It's not WX that you need to be mad at here.

But if WX are churning out data that is guesswork at best, then some criticism does need sending their way too.

 

[Darandio]

But if WX are churning out data that is guesswork at best, then some criticism does need sending their way too.

They aren't churning out data that's guesswork. They just display forecast models from T-000 to T-360 like any other similar website. If someone at Reach during the summer then sees a load of bright red on a model at T-168, they'll run a story telling us we're all gonna burn to a crisp exactly a week later.

If you still need to dish out criticism then forget WX or Reach, go after the likes of European Centre for Medium-Range Weather Forecasts, Global Forecast, UK Met Office, Application of Research to Operations at Mesoscale etc etc. It's their supercomputers that are providing the models!

== Doublepost prevention - post automatically merged: 28 Jun 2026 ==

What I would say is this is exactly where something like WXCharts can be helpful. It's aggregating model data so people (particularly weather enthusiasts) can view and make their own estimates and predictions. Take the post earlier in this thread showing a model with predictions of upwards of 40 degrees celcius on 11th July. You can view these charts from multiple weather modelling computers around the world on WX and others and they are often updated multiple times a day with wildly varying results even within hours. Many models are predicting warm weather for that period here but there's no agreement between models that it's going to be that hot.

 

[DesDobramento]

An unavoidable Southeastern class 395/LNER Azuma/Scotrail class 170 journey on Saturday 27 June (hot in the south, much cooler beyond Newcastle) was virtually hitch-free on busy trains. Full marks to the LNER train manager who asked passengers to keep the window blinds fully down to help the air-conditioning to do its job against the strong sunlight, and to keep vestibules free of luggage obstructing doors, again to allow the a/c to do its job properly by ‘sealing’ the saloons from the hotter vestibules.

 

[johncrossley]

This Met Office video from last year highlighted the dangers of looking at long range forecasts. The right-wing media seized upon a single model run from a free weather prediction site which showed a heatwave, but ignored several other model runs from the same site which didn't. There was no heatwave.

30/05/2025 - Summer vibes? - Weather Studio Live - Met Office UK Weather

This weekend we switch from spring to summer (meteorologically) but has anyone told the weather? Is there any heat on the horizon or will the changebale weat...

www.youtube.com

 

[Bletchleyite]

An unavoidable Southeastern class 395/LNER Azuma/Scotrail class 170 journey on Saturday 27 June (hot in the south, much cooler beyond Newcastle) was virtually hitch-free on busy trains. Full marks to the LNER train manager who asked passengers to keep the window blinds fully down to help the air-conditioning to do its job against the strong sunlight

Completely unnecessary and spoiling the experience, as well as making some people (who might be more travel-sick than usual due to the heat) feel worse. No, very much NOT a good thing to suggest. Zero marks.

As I noted above last time it was 40 degrees I travelled on a GWR 80x from Bodmin to Paddington and it was working just fine without the blinds down, like sitting in a fridge.

Culturally hot countries do seem to do this but it's not necessary. The system can cope on modern units.

 

[CaptainHaddock]

An unavoidable Southeastern class 395/LNER Azuma/Scotrail class 170 journey on Saturday 27 June (hot in the south, much cooler beyond Newcastle) was virtually hitch-free on busy trains. Full marks to the LNER train manager who asked passengers to keep the window blinds fully down to help the air-conditioning to do its job against the strong sunlight, and to keep vestibules free of luggage obstructing doors, again to allow the a/c to do its job properly by ‘sealing’ the saloons from the hotter vestibules.

Full marks? I'd give him zero marks!

No matter how hot it is, where's the pleasure in a railway journey if you can't enjoy the scenery as you travel? And how are you supposed to know when you're nearing your destination if you have no idea where you are?

By all means keep your passengers cool but don't use the heat as an excuse to spoil their journey.

 

[DesDobramento]

Completely unnecessary and spoiling the experience, as well as making some people (who might be more travel-sick than usual due to the heat) feel worse. No, very much NOT a good thing to suggest. Zero marks.

As I noted above last time it was 40 degrees I travelled on a GWR 80x from Bodmin to Paddington and it was working just fine without the blinds down, like sitting in a fridge.

Culturally hot countries do seem to do this but it's not necessary. The system can cope on modern units.

On a crowded 802, it was not in any way fridge-like - really quite clammy, but we were glad to be getting punctually to our destination on an unavoidable journey. The Scotrail 170 was more fridge-like.

A recent Avanti class 390 journey in the ‘saloon’ end of coach C was so fridge-like that condensation started flooding from the ceiling - possibly because the a/c was struggling to deal with the greater heat generated at the ‘shop’ end of the vehicle.

 

[londonmidland]

I find the aircon on 170s 50/50.

When it does work, it can get very cold.

When it doesn’t work, it can get very uncomfortable, fast. Made worse that you cannot open the windows on most of the 170 variants.

 

[Darandio]

Full marks? I'd give him zero marks!

No matter how hot it is, where's the pleasure in a railway journey if you can't enjoy the scenery as you travel? And how are you supposed to know when you're nearing your destination if you have no idea where you are?

By all means keep your passengers cool but don't use the heat as an excuse to spoil their journey.

I'm struggling to comprehend why anyone would criticise a member of staff for trying to mitigate the effects of solar radiation to make a passenger journey more comfortable, in fact it absolutely baffles me.

 

[Bletchleyite]

I'm struggling to comprehend why anyone would criticise a member of staff for trying to mitigate the effects of solar radiation to make a passenger journey more comfortable, in fact it absolutely baffles me.

Because (a) I like looking out of the window, and (b) I can sometimes (particularly in a Pendolino) get a bit queasy if I'm unable to see out.

This is more important to me than a degree or two.

 

[bramling]

I'm struggling to comprehend why anyone would criticise a member of staff for trying to mitigate the effects of solar radiation to make a passenger journey more comfortable, in fact it absolutely baffles me.

I wouldn’t be happy TBH. In fact, I’d have been pretty annoyed. The train manager should learn to keep their nose out of matters which don’t really concern them.

 

[Purple Train]

Completely unnecessary and spoiling the experience, as well as making some people (who might be more travel-sick than usual due to the heat) feel worse. No, very much NOT a good thing to suggest. Zero marks.

I love looking out of the window on train journeys and would be disappointed to be denied this opportunity; however, based on my experience on Friday when my blind (which was most of the way down such that I could see through the window while in the shade - I'm 5ft 7) was opened by the charming sunseeker behind me from Totnes to Exeter, the blind absolutely does make a difference to the temperature, although I agree that "all the way down" is a little over the top.

As I noted above last time it was 40 degrees I travelled on a GWR 80x from Bodmin to Paddington and it was working just fine without the blinds down, like sitting in a fridge.

I don't think that's a universal experience, although as someone who travels semi-regularly on IETs it's comforting to know that it's a possibility! They're not terribly hot by any means, but definitely not super cool in my experience.

 

[Bletchleyite]

I love looking out of the window on train journeys and would be disappointed to be denied this opportunity; however, based on my experience on Friday when my blind (which was most of the way down such that I could see through the window while in the shade - I'm 5ft 7) was opened by the charming sunseeker behind me from Totnes to Exeter, the blind absolutely does make a difference to the temperature, although I agree that "all the way down" is a little over the top.

Blinds being open on the seaward side on the Dawlish section should be mandatory. It's one of the best stretches of scenery on the network, and it's at its absolute best on a hot sunny day.

I suppose to be fair the ECML is utterly boring except a couple of short sections...

 

[johncrossley]

Why are blinds even installed? They are unnecessary and aren't installed on local trains. They just increase the likelihood of conflict between passengers.

 

[Purple Train]

Why are blinds even installed? They are unnecessary and aren't installed on local trains. They just increase the likelihood of conflict between passengers.

I agree with you on conflict - they make me very thankful that I'm a bit of a wet blanket! - but they do make a difference if the sun is very strong, as it was last week. Presumably less necessary on local trains because of the short distances involved: toilets, after all, are not installed on many local trains.

 

[Sparks807Evo]

Experience last week air con wise was predominantly fine - couple of Pendos had the odd coach going into furnace mode, one leaking and one Evero with a stuffy coach. Otherwise did fairly well - going back to the blinds point, it is interesting to note that when getting on after being undercover in Euston the units were noticeably cooler.

Aircraft on turnarounds in hotter climates sometimes have the shades down, but that is only because you may not have the auxiliary power unit on for air con or a connected cold air hose. Blinds probably help a little but unlike aircraft still allow some light through. To be honest really just need to making sure the air con units are working. From experience the more modern Bombardier 172 / 387s best in my experience. Would concur the 730s (particularly the /2s) are fairly poor both from a cooling and heating perspective!

 

[45Fox]

Because (a) I like looking out of the window, and (b) I can sometimes (particularly in a Pendolino) get a bit queasy if I'm unable to see out.

This is more important to me than a degree or two.

Agreed. One of the selling points of rail travel is the view, which incidentally is getting seriously degraded on many routes with the railway becoming increasingly like a linear arboretum.
If you can't enjoy the scenery you may as well go by coach or domestic flight, probably at a cheaper price and, in the case of flying, taking less time.

 

[Segedunum]

Because (a) I like looking out of the window, and (b) I can sometimes (particularly in a Pendolino) get a bit queasy if I'm unable to see out.

This is more important to me than a degree or two.

Staff have been told to keep blinds down during turnarounds and while empty stock has been sat in the sun to lower the load on the AC units. Certainly at no point are passengers being forced to have window blinds down while in service if they want to see out.

From my experience last Thursday afternoon most passengers on the west side of the train were electing to have blinds down anyway as the sunlight made quite a bit more difference than a degree or two.

 

[Archvile]

A point of order regarding blinds... Avanti TMs are  required to make these announcements and they are suggestions, not orders.

On a 390 with struggling HVAC, it does make a demonstrable difference.

Most people choose trains for convenience, not the view, and I'd say 90% of blinds remained down during the recent hot spell.

 

[Bikeman78]

We are however seeing an increase in traincrew who are saying that the passengers may be willing to put up with the train being so hot but they aren't interested in heatstroke so refusing to work.

To be honest, I don't really blame them. I don't cope well with heat at all.

Despite my best efforts, the evening temperature in my house rose by around two degrees each day. On Thursday it reached the 30 degree mark upstairs for the first time since I have lived here. I felt drained simply sitting in the living room doing nothing, never mind trying to drive a train.

My tolerance for heat has reduced as I've got older. I don't go on Euro bashing trips in summer anymore, and always book hotels with air con between April and October.

 

[Krokodil]

I wouldn’t be happy TBH. In fact, I’d have been pretty annoyed. The train manager should learn to keep their nose out of matters which don’t really concern them.

The conditions on the train are the Train Manager's business. They're the one who has to deal with anyone who faints.

Besides, no one is forcing you to keep the blinds down, it's merely advice.

 

[Iskra]

The conditions on the train are the Train Manager's business. They're the one who has to deal with anyone who faints.

Besides, no one is forcing you to keep the blinds down, it's merely advice.

But advising their use is likely to lead to conflict, as some overzealous passengers will interpret that as them being mandated. It would possibly be better if they simply said something like 'window blinds are available on this train should you need them.'

- - - - -

On a different matter, is it likely that the increased amount of trains on depots over the last week will result in improved fleet availability going forwards?

 

[sh24]

100% down on my Pendo rides last week. 99.9% of passengers are more interested in keeping cool.

 

[speedy1]

If you give the DfT bean counters an inch they'll take a mile: "As a result of customer feedback we've decided to permanently keep blinds down May to September for eco / save the planet / someone think of the polar bear reasons", while they figure out how to save a few pence on the next rolling stock order's aircon spec.

I mean, what a monster you are for wanting them up and basically asking for people to faint / get sick / lead to disruption

 

[Falcon1200]

Presumably the blinds only need to be down on the side of the train onto which the sun is shining?!!