Date of first and last AIR frost

[Stratos Ferric]

There's a few people on here with decent sets of longitudinal data FOR ONE SITE. It might be interesting to produce an analysis to see how these dates seem to be changing.

If those people (e.g. PIT, TM, OON, John etc.) are willing to supply the info I'll happily crunch the numbers.

Please, though, only provide data IF you have robust kit; i.e. a good automatic set-up or a traditional thermometer sited and housed to something like UKMO standards. Not interested in qualitative assessments e.g. the lawn first looked frosty on...

[Osbourne One-Nil]

Oh..this brings out the real nerd in me. I love it!

Winter 98/99

First air frost - October 17th

Last air frost - April 17th

Total nights of air frost - 57 (coldest -8.0º twice)

Winter 99/00

First air frost - October 4th

Last air frost - April 15th

Total nights of air frost - 44 (coldest -8.5º)

Winter 00/01

First air frost - November 2nd

Last air frost - June 2nd

Total nights of air frost - 75 (coldest -11.3º)

Winter 01/02

First air frost - November 4th

Last air frost - May 11th

Total nights of air frost - 58 (coldest -10.8º)

Winter 02/03

First air frost - October 17th

Last air frost - May 14th

Total nights of air frosts - 61 (coldest -8.4º)

Winter 03/04

First air frost - October 4th

Last air frost - April 19th

Total nights of air frost - 74 (coldest -10.0º)

Winter 04/05

First air frost - November 12th

Last air frost - May 17th

Total nights of air frost - 58 (coldest -6.7º)

Winter 05/06

First air frost - November 13th

Last air frost - April 24th

Total number of air frosts - 74 (coldest -11.1º)

Winter 06/07

First air frost - October 31st

Not quite sure what this proves, other than I don't live in Surrey.

[Nick H]

Not quite sure what this proves, other than I don't live in Surrey.

Don't be so sure, I bet Redhill Aerodrome and/or some of the valleys just south of Croydon see about 60-70 air frosts a year!

[Osbourne One-Nil]

Alright then....Cornwall.

[Terminal Moraine]

Here's my list, all from the same site with met' office standard instruments.

On the list with first and last air frosts the year relates to the autumn date, so on the first entry Nov 17th is in 1977 and Apr' 15th is in 1978 etc etc.

The number of air frosts is from January to December in the given year.

1977...Nov' 17th...Apr' 15th

1978...Nov' 25th...May 6th............72

1979...Nov' 9th....Apr' 9th.............94

1980...Nov' 3rd....May 5th............57

1981...Oct' 26th...May 5th.............70

1982...Nov' 14th...Apr' 20th............61

1983...Oct 29th....Apr' 12th...........57

1984...Nov' 16th..Apr 29th.............66

1985...Nov' 2nd...Apr' 13th............82

1986...Nov' 21st..March 29th..........81

1987...Nov' 28th..Apr' 24th............70

1988...Nov' 4th....Apr' 26th............41

1989...Nov' 24th...Apr' 17th...........41

1990...Nov' 21st...Apr' 21st...........34

1991...Nov' 4th....Apr' 15th...........61

1992...Oct' 31st...March 27th.........45

1993...Oct' 16th...Apr' 18th............58

1994...Oct' 4th....May 13th............51

1995...Nov' 17th...May 4th............60

1996...Nov' 18th...May 7th............84

1997...Oct' 29th....Apr' 16th...........29

1998...Nov' 16th...Apr' 15th...........38

1999...Nov' 18th...Apr' 16th...........35

2000...Nov' 21st...Apr' 21st...........33

2001...Nov' 9th....Apr' 8th............59

2002...Dec' 9th....Apr' 10th...........27

2003...Nov' 27th...March 13th........42

2004...Nov' 13th...Apr' 9th............40

2005...Nov' 17th...Apr' 10th..........41

2006...?

T.M

[Osbourne One-Nil]

Now THAT shows something!

[pinball wizard]

Oh..this brings out the real nerd in me. I love it!

Winter 98/99

First air frost - October 17th

Last air frost - April 17th

Total nights of air frost - 57 (coldest -8.0º twice)

Winter 99/00

First air frost - October 4th

Last air frost - April 15th

Total nights of air frost - 44 (coldest -8.5º)

Winter 00/01

First air frost - November 2nd

Last air frost - June 2nd

Total nights of air frost - 75 (coldest -11.3º)

Winter 01/02

First air frost - November 4th

Last air frost - May 11th

Total nights of air frost - 58 (coldest -10.8º)

Winter 02/03

First air frost - October 17th

Last air frost - May 14th

Total nights of air frosts - 61 (coldest -8.4º)

Winter 03/04

First air frost - October 4th

Last air frost - April 19th

Total nights of air frost - 74 (coldest -10.0º)

Winter 04/05

First air frost - November 12th

Last air frost - May 17th

Total nights of air frost - 58 (coldest -6.7º)

Winter 05/06

First air frost - November 13th

Last air frost - April 24th

Total number of air frosts - 74 (coldest -11.1º)

Winter 06/07

First air frost - October 31st

Not quite sure what this proves, other than I don't live in Surrey.

Well the years that had the first frost in Nov seemed to have colder minima...

[Dawlish]

Here's my list, all from the same site with met' office standard instruments.

On the list with first and last air frosts the year relates to the autumn date, so on the first entry Nov 17th is in 1977 and Apr' 15th is in 1978 etc etc.

The number of air frosts is from January to December in the given year.

1977...Nov' 17th...Apr' 15th

1978...Nov' 25th...May 6th............72

1979...Nov' 9th....Apr' 9th.............94

1980...Nov' 3rd....May 5th............57

1981...Oct' 26th...May 5th.............70

1982...Nov' 14th...Apr' 20th............61

1983...Oct 29th....Apr' 12th...........57

1984...Nov' 16th..Apr 29th.............66

1985...Nov' 2nd...Apr' 13th............82

1986...Nov' 21st..March 29th..........81

1987...Nov' 28th..Apr' 24th............70

1988...Nov' 4th....Apr' 26th............41

1989...Nov' 24th...Apr' 17th...........41

1990...Nov' 21st...Apr' 21st...........34

1991...Nov' 4th....Apr' 15th...........61

1992...Oct' 31st...March 27th.........45

1993...Oct' 16th...Apr' 18th............58

1994...Oct' 4th....May 13th............51

1995...Nov' 17th...May 4th............60

1996...Nov' 18th...May 7th............84

1997...Oct' 29th....Apr' 16th...........29

1998...Nov' 16th...Apr' 15th...........38

1999...Nov' 18th...Apr' 16th...........35

2000...Nov' 21st...Apr' 21st...........33

2001...Nov' 9th....Apr' 8th............59

2002...Dec' 9th....Apr' 10th...........27

2003...Nov' 27th...March 13th........42

2004...Nov' 13th...Apr' 9th............40

2005...Nov' 17th...Apr' 10th..........41

2006...?

T.M

That's where careful and dedicated amatuer recording really comes into its own. Any recording error (and there will be little) is drowned by the wealth of data. Thanks TM. Long may you and many others continue. Is anyone capable of putting this in a graph, running a regression analysis on it and seeing what the trend is and how significant it is? I can't do the techie bits!

Paul

Edited November 11, 2006 by Dawlish

[Stratos Ferric]

That's where careful and dedicated amatuer recording really comes into its own. Any recording error (and there will be little) is drowned by the wealth of data. Thanks TM. Long may you and many others continue. Is anyone capable of putting this in a graph, running a regression analysis on it and seeing what the trend is and how significant it is? I can't do the techie bits!

Paul

When my daughters have come off the PC (they are immersed in a disc of retro 80s ATARI arcade games I bought the other week: lunar lander, gravitar, asteroids and that brilliant tank game, Battlezone, where the world was all geometric shapes and first you knew you'd been blown up was when your screen cracked) I will complete the plot of TM's and OON's data. The early headline is that, no surprise, there is a clear trend.

[Stratos Ferric]

Here's the first plot. Across TM's data, and using first frost as the indicator, winter has shortened by eight days at either end on the basis of the ten year rolling average.

[Thundersquall]

1979...Nov' 9th....Apr' 9th.............94

T.M

1979/80 was a very frosty winter judging by this figure!

Edited November 12, 2006 by Thundersquall

[Stratos Ferric]

1979/80 was a very frosty winter judging by this figure!

I think that will be 1978-79. My own records for that winter showed frost on every day bar two from Dec 29 - Feb 28. In the same period it snowed on 28 days, and snow lay continuously right through this period; something which helps when it comes to air frost.

That winter, using an unscreened thermometer, I recorded 117 frosts from October 18th to May 6th, and it was still snowing then - I recorded snow every day from May 1st-5th.

I don't expect that I shall ever see another winter like it.

Edited November 12, 2006 by Stratos Ferric

[Terminal Moraine]

I think that will be 1978-79. My own records for that winter showed frost on every day bar two from Dec 29 - Feb 28. In the same period it snowed on 28 days, and snow lay continuously right through this period; something which helps when it comes to air frost.

That winter, using an unscreened thermometer, I recorded 117 frosts from October 18th to May 6th, and it was still snowing then - I recorded snow every day from May 1st-5th.

I don't expect that I shall ever see another winter like it.

Correct with your first sentence, Stratos.

I recorded 99 air frosts that 'winter' between November and May and 93 mornings with lying snow over the same period. The last morning with lying snow ( at 0900 g.m.t ) was May 1st and there was falling snow on each of the first 6 days of May. Snowdrifts up to 10m deep filled the cuttings on the old High Peak Railway line and the remnants lasted until early June.

Like you, I'll be surprised if I see another winter like that.

As you're good with graphs and number crunching I'll submit a list of first and last air frosts for another station which has been run by me or a member of my family since 1963 as soon as I get the time to extract the data.

It's at a much lower altitude and more susceptible to early and late frosts than my current location.

T.M

[Stratos Ferric]

Correct with your first sentence, Stratos.

I recorded 99 air frosts that 'winter' between November and May and 93 mornings with lying snow over the same period. The last morning with lying snow ( at 0900 g.m.t ) was May 1st and there was falling snow on each of the first 6 days of May. Snowdrifts up to 10m deep filled the cuttings on the old High Peak Railway line and the remnants lasted until early June.

Like you, I'll be surprised if I see another winter like that.

As you're good with graphs and number crunching I'll submit a list of first and last air frosts for another station which has been run by me or a member of my family since 1963 as soon as I get the time to extract the data.

It's at a much lower altitude and more susceptible to early and late frosts than my current location.

T.M

Happy to oblige. Surely one or two others on here have a decent run of data; PIT, JH? I'll add in OON's, though his run is only just long enough to start to run a decent time series on it.

[Nick H]

Year refers to the winter that started in December of that year, e.g. 1979 = Dec 1979, Jan 1980 and Feb 1980.

Number of air frosts are for the calendar year, e.g. 1979 = Jan 1 1979 to Dec 31 1979.

1979 Nov 10 May 8 (56)

1980 Nov 2 Apr 23 (43)

1981 Dec 8 Mar 8 (47)

1982 Nov 28 Apr 3 (32)

1983 Oct 30 Apr 5 (36)

1984 Dec 18 Apr 26 (24)

1985 Nov 3 Apr 13 (57)

1986 Jan 7 (sic) Mar 20 (45)

1987 Nov 28 Mar 5 (53)

1988 Nov 5 Apr 27 (19)

1989 Nov 24 Apr 9 (23)

1990 Dec 6 Mar 30 (14)

1991 Nov 21 Feb 25 (38)

1992 Dec 17 Mar 28 (28)

1993 Oct 16 Feb 23 (29)

1994 Dec 15 Apr 19 (20)

1995 Nov 18 Apr 6 (31)

1996 Nov 14 Apr 22 (56)

1997 Oct 30 Apr 12 (22)

1998 Nov 17 Apr 15 (25)

1999 Dec 14 Mar 26 (19)

2000 Dec 16 Mar 19 (16)

2001 Nov 14 Mar 3 (43)

2002 Dec 10 Apr 11 (15)

2003 Dec 8 Apr 11 (36)

2004 Nov 14 Apr 9 (33)

2005 Nov 14 Ap 10 (43)

2006 mmm dd mmm dd (33*)

Location, Herts, c. 160m asl.

Edited November 12, 2006 by Nick H

[Stratos Ferric]

Thanks Nick, I'll add that lot in (might be next w/e before I do).

[summer blizzard]

Perhaps this thread may be better placed in the historical section.

[johnholmes]

Thanks Nick, I'll add that lot in (might be next w/e before I do).

only just seen this SF will post my 10 years and the Finningley dtaa for about 60 years as I get time..

tks for doing this

John

[Terminal Moraine]

Apologies, Mod's, if this topic, originally started by Stratos Ferric, is still in existence but I couldn't find it anywhere and have had to resurrect it.

Anyway here is a list of first and last air frosts from 1964 to date at about 150m in mid-Derbyshire.

As before, the autumn date occurs in the year on the left side of the list so, for instance ,the line for 1964 is October 13th 1964 to April 1st 1965. The number of air frosts for the year refers to the calendar year.

1964.....Oct' 13th....April 1st.............44

1965.....Nov' 13th...April 16th...........63

1966.....Oct' 24th...May 3rd.............54

1967.....Nov' 7th....Apr' 12th............45

1968.....Nov' 4th.....Apr' 20th............70

1969.....Nov' 5th.... Apr' 28th............79

1970.....Nov' 13th.. Apr' 28th............70

1971.....Nov' 7th... Apr' 9th..............41

1972.....Oct' 21st...Apr' 10th............41

1973.....Oct' 17th....Apr' 30th............61

1974.....Oct' 31st....May 31st............45

1975.....Nov' 13th...Apr' 29th............47

1976.....Nov' 3rd.....May 14th............63

1977.....Nov' 17th...Apr' 28th............42

1978.....Nov' 25th...May 6th..............60

1979.....Nov' 10th...Apr 26th.............90

1980.....Oct' 10th....May 5th..............51

1981.....Oct' 16th....May 5th..............63

1982.....Oct' 24th....Apr' 20th............61

1983.....Oct' 22nd...May 9th..............60

1984.....Oct' 27th....Apr' 28th............57

1985.....Nov' 2nd....Apr' 13th............75

1986.....Nov' 12th...May 19th............71

1987.....Oct' 23rd....Apr' 25th............63

1988.....Oct' 30th....Apr' 28th............41

1989.....Nov' 5th.....Apr' 28th............48

1990.....Oct' 8th......Apr' 21st............40

1991.....Nov' 4th.....Apr' 4th..............70

1992.....Oct' 16th....Apr' 15th............48

1993.....Oct' 15th....Apr' 11th............47

1994.....Nov' 29th....May 18th...........47

1995.....Nov' 5th......May 8th.............56

1996.....Nov' 8th......Apr' 21st...........67

1997.....Oct' 25th.....Apr' 16th...........43

1998.....Oct' 18th.....Apr' 18th...........38

1999.....Nov' 7th......Apr' 16th...........33

2000.....Nov' 14th....Apr' 13th...........39

2001.....Nov' 10th....Apr' 16th...........59

2002.....Oct' 19th.....Apr' 11th...........30

2003.....Oct' 21st.....Apr' 9th.............66

2004.....Nov' 14th....May 17th...........37

2005.....Nov' 14th....Apr' 11th...........44

2006.....Nov' 2nd......?

T.M

Edited November 27, 2006 by Terminal Moraine