Last frost dates near Guildford - this can’t be right can it?

I was just wondering about the last frost dates in our area, as they seem to be getting gradually earlier. I found a webpage called plantmaps which confirmed roughly what I thought about our area in West Wales. Then I had a look around to find the latest frost dates in the UK, and apparently it’s not in the Highlands, as I expected, it’s somewhere just to the west of Guildford - last frost date June 10th - June 20th. Do you live in this area? Is there a huge frost pocket around there? Why is it like this?

 

I used to work with someone who had a story about frost and snow in a June. It must have been many years ago. There have always been oddities and extreme weather events, I wouldn't expect that to happen very often

 

I remember snow in early June in London. One day. A long time ago

 

June 1975 it snowed here in Cambridge. I was working on a project at the airport here getting ex RAF Canberra's serviced for the Peruvian air force, we all went outside with the Peruvian reps and had a snow ball fight.

 

I'm putting my overwintered osteos out soon.

 

Thanks, @Fat Controller, I suspected as much. I couldn’t see how an area in the South East could have a last frost date this late. So I can now take the dates for my area with a largish pinch of salt as well.

 

There is an area to the west of Guildford, being the northern side of the Hogs Back, roughly Rydes hill- Tongham which has a notable frost pocket due to shadow from the rising sun and a elevation rising to 500ft. This also extends westwards beyond Farnham towards Winchester but is less noticeable. I suffered frost damage in late May & even 3rd June to beans and courgettes growing near Crondall in , I think, 2016 and 2018
EDIT
Just referred to the plantmaps site, the area I was in is Zone 13. The area they show as the latest is around Leith Hill which tops out at 965 ft

 

I don't know that area but as I understand it low ground is more susceptible to late frost rather than higher ground.
The term frost hollow says it all, so cold air runs down hill on those spring and autumn nights.

 

@Emerion I am also in Carmarthenshire, having retired here (back home) from many years in rural Nottinghamshire. Yes, the frosts were later and nastier there, but down in wet Wales we get the problem that things keep growing too late and start again too early, and are more vulnerable if we do get a frost. December 22 killed a lot of plants for me.

 

Being on higher ground in Carmarthenshire we can occasionally get a late frost here, sometimes into April, but it's rare and usually just on the roof tops.

I remember heavy snow one April, but that was the only time in over 70 years.

 

@Emerion if that picture is from last then it’s the same when I also asked in the GW forum if the BBC weather forecast knows more than any other forecast. It turned out that there was a script problem with a third-party script that is needed to make a forecast. The BBC showed freezing temperatures in summer for 3 days on telly

 

@simone_in_wiltshire I think it’s meant to be the usual expected last frost date, not just what happened last year. But if they had incorrect data for 3 years running I suppose that could have falsely affected last frost dates.