You won’t need a cold air flow. In fact no air flow would be better. With a cold day and a forecast of clearing skies with light winds in many places, I suspect there will be a number of northern locations recording an air frost. It will however take something notable to beat the -5°C earlier in the week.

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5.6c at 06:17 This Morning.

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Not much of a source available for deep cold air yet - Iceland is covered in snow and there's some on the mountains in Norway - but look at the amount of open water in the Arctic. icebreakers - who needs them?

https://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_asiaeurope.gif

 

It doesn't take a genius to realise that northerlies are not once what they were, when you look at the pathetic amount of ice cover remaining.  To think London received snow in September back in the last 250 years.

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Max here today 11.1c

Now sure what the England date record is for today!

Forecast has changed from a mostly clear weekend to more or less total overcast. No frost on the way down here - forecast min for tonight was 4C a few days ago, now it’s 8C.

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Got down just just under 5°C this morning. Chilly for September, but not that rare around here...

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Thoroughly diabolical day with frequent and heavy showers of drizzle and just 9.5C.

 

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Max here today 11.1c

Now sure what the England date record is for today!

For England the lowest September day max 6.2C and that was on the 27th.. don't know about date record though for the 26th. 

Coldest Sept day for UK is 4.4C.

First frost of the season here with temps just nudging below zero early this morning.

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Sparkling clear blue sky here with wall to wall sunshine.A dramatic drop in temperature though from monday when it was 24c today 14 despite the sunshine. Not complaining though and glad to see autumn finally arrive and no more suffering from heat until at least may next year

This can be added to the long list of notable weather that we miss out on. The list pretty much consists of every single notable weather event these days 

Forecast min is 8C tonight. That is unreal. It's above average and would be the mildest minimum for over a week. Milder than when we had 20C+ maxes last week. Culprit is the putrid wind which has rendered today a disgusting and depressing write-off. Looks like it won't drop out until tomorrow morning which will be too late to see a notable cold temperature 

Forecast accuracy is shocking these days but it seems unlikely that this month's low of 4.1C will be beaten now. First September since 2016 not to get below 4C. A complete waste of cold upper air just like the dire 'Beast From the East' which was scuppered by cloud. Can't get light winds and clear skies any more in the most infuriating place for a weather enthusiast to live.

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This can be added to the long list of notable weather that we miss out on. The list pretty much consists of every single notable weather event these days 

Forecast min is 8C tonight. That is unreal. It's above average and would be the mildest minimum for over a week. Milder than when we had 20C+ maxes last week. Culprit is the putrid wind which has rendered today a disgusting and depressing write-off. Looks like it won't drop out until tomorrow morning which will be too late to see a notable cold temperature 

Forecast accuracy is shocking these days but it seems unlikely that this month's low of 4.1C will be beaten now. First September since 2016 not to get below 4C. A complete waste of cold upper air just like the dire 'Beast From the East' which was scuppered by cloud. Can't get light winds and clear skies any more in the most infuriating place for a weather enthusiast to live.

I know when it get snow cover here the clouds refused to clear off to allow very low temps and never see this since Feb 1991 when one night was clear and -12C.  Always when we get potential heat or cold the clouds ruin it every time and don't leave you alone just for those moment.  I remember seeing posts from SE quarter they get stress with clouds ruining it.  

Here in Edinburgh, last night's overnight minimum temperature was -1.7°C at Edinburgh Gogarbank and around -3°C at Edinburgh Airport.

I have been looking back at the records going all the way to the year 2000 and up until last night, the lowest overnight minimum temperature which I could see as being recorded during September was 0.7°C as recorded on 27 September 2007 at Edinburgh Gogarbank.

Amongst all of that data, I have not been able to find any other occasion apart from last night, where an official air frost has been recorded here in Edinburgh during the month of September (if anyone else can find such an occasion, I will be more than happy to hear about that on this thread).

In all of the years that I have lived, I can remember there being a lot of frosty mornings during the autumn, but I don't remember any these occurring any earlier than October.

Furthermore, Edinburgh Gogarbank is only a relatively new station which has only been around since around 2005 so when all of the above is taken into consideration, last night is looking likely to have been the coldest September night on record at that particular station at least.

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This can be added to the long list of notable weather that we miss out on. The list pretty much consists of every single notable weather event these days 

 

What about the torrential rain of August 12th? The event that caused the fatal Stonehaven train crash. You certainly didn't miss out on that one.

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A frosty start here. Edinburgh Airport -3 C and Gogarbank -2 C.

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Last night was officially the coldest September night on record in N Ireland.

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Overnight low was 10C here. A far cry from the 3-4C lows forecast a few days ago.

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It doesn't take a genius to realise that northerlies are not once what they were, when you look at the pathetic amount of ice cover remaining.  To think London received snow in September back in the last 250 years.

And yet Northern Ireland breaks its September minimum record.   Not quite sure what to make of that!

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That’s our 3rd consecutive night with an air frost. Grass and trampoline were frosted over by 9pm last night and still covered now.

So pleasing. 😎

I’m in rural East Ayrshire, near to the village of Sorn.

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Lowest tody 6.4c.

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