General and Barometric Pressure

  September had a little bit of most things during the month - warm, dry and sunny spells, colder periods with the first frosts of the season, but also the warmest day of the year. There were a couple of wet days along the way, however, and whilst it doesn't saying much about 2024 so far, there was a run of six consecutive days with no rain that is the longest such run so far in 2024.

  This will be the first time in my records that September has provided the year's warmest day, but this came during a short-lived warm spell, but the period of the 16-19th was simply glorious with wall to wall sunshine and which was pleasantly warm. Prior to this fine weather, a cold blast of Arctic had given an air frost on the 13th which is now a new record for this site for being the earliest autumn date to record such.

  And for the first time since January, MSLP would finish above average, albeit by just 0.9 MB. Pressure was fairly transient during the month with pressure rarely staying low or high for long, the period of 16-20th with high pressure being the longest dominant spell.

  The month opened on a damp note, the 1st having rain (16.4 mm) from 1530h through the evening, but any showers over the next three days were mainly at either end of the day. Temperatures were slightly above average, but surged upwards up on the 6th on what was a hot and sunny day as Cumbria was broadly sheltered in a slack pressure gradient. A maximum of 25.7°c wouldn't just be a month's high, but also a year's high; warmer than anything the summer could offer!

  The 7th saw more cloud and haze, but was still a warm day at 21.9°c, but the month's wettest day would follow on the 8th. A hazy morning saw rain arrive late a.m. and become progressively heavier as the day progressed to give a total of 25.4 mm. The 9th would improve during the day as the low pressure that had pushed north up the east coast from the English Channel on the 8th cleared away.

  It then became cooler as a cold front swept down from the north bringing a strong NW'ly flow behind it. The 10-14th now had maximum temperatures in the range of 13-14°c and then come the 12th high pressure began to nudge in from the Atlantic, which quietened the weather but maintained the NW'ly flow. With calm conditions and clear skies the 13th would start with an air frost of -0.5°c and by four days became the earliest autumn date in my records to record such.

  There had been the odd shower on each of the 11-15th with the high pressure getting squeezed south by another cold front from the NW, but later on the 15th high pressure would start to re-assert itself and would become the dominant feature through to the 19th - this gave four superb days.

  All of the 16-19th were dry, sunny, pleasantly warm and just lovely. Only the 16th, just, failed to attain 20°c and the days could not have been any better.

  The 21st also stayed dry in total we had had six consecutive days with no rain - the most so far this year! However, day-time temperatures would be consistently below average, the 24th the warmest at 14.2°c, but fallen to 10.5°c on the 26th. And most of these days saw some rainfall, the 25th with 14.5 mm having the most, but most of this fell at night and overnight into the 26th. The 26th was a dark and overcast day and sunshine now was quite rare, but under clear skies the 28th squeezed in a second air frost for the month.

  Temperature

  With a mean minimum of 7.78°c and a mean maximum of 16.45°c September 2024 saw the temperature 0.56°c below the fifteen year average for this site. This saw it being the coldest September since 2020 and since the record commenced (2009), ten have been warmer and five have been colder.

  The month probably behaved as it should, that is, a warmer first half (mean of 13.008°c) and then a progressively cooler second half (mean of 11.23°c).

  The highest maximum during the month was 25.7°c (78.3°f - 6th) and the lowest minimum, -0.5°c (31.1°f - 13th).

  At the Met' Office site at Shap a mean minimum of 7.1°c and a mean maximum of 15.5°c saw the monthly mean temperature 0.25°c below average. It was the coldest September since 2020 and since the record began (1992), nineteen have been warmer, eleven have been colder and two were exactly the same.

  Precipitation

  At Maulds Meaburn rainfall totalled 95.2 mm (3.75 In), this being 100.3% of the average for 2007-23, making it the driest September since 2021. Since the recorded began (2007), eight have been drier and nine wetter.

  Locally rainfall at Maulds Meaburn North was 93.9 mm and at Castlehowe Scar 108.8 mm. At the Met' Office site at Shap, rainfall of 98.6 mm represents 75.2% of its average making it the driest September there since 2021. And since the record commenced (1989), eleven have been drier and twenty-four wetter.

  Figures from a selection of Environment Agency's rainfall sites were, (figure in brackets being the monthly average for 1991-2020)   'Data kindly provided by the Hydrometry and Telemetry team of the Environment Agency (Penrith)':

  At Appleby in Westmorland rainfall of 106.7 mm (LTA of 77.4 mm) represents 137.9% of its average (1856-2023) and made it the driest since 2022 - since the record commenced, 130 have been drier, 36 have been wetter and two were exactly the same.

  Kirkby Thore 88.0 -- (64.1 mm)

  Haresceugh Castle (Kirkoswald) 78.6 -- (84.1 mm)

  Brothers Water 129.15 mm -- (214.4 mm)

  Seathwaite Farm (Borrowdale) 192.0 mm -- (291.8 mm [average for 1845-2023]) represents 65.8% of its average - and made it the driest since 2015 - since the record commenced, 50 have been drier and 129 have been wetter.

  OTHER:-

  During the month the following 'days of' were recorded: absolutely nothing -- the wind speed averaged 3.77 mph, with a maximum gust of 40 mph (14th).

  We had 2 Air Frosts in the month (year 25)          --          Grass Frosts totalled 3 (year 60).

  The 1 foot soil temp ranged from a low of 11.5°c on the 29th        to      a high of 15.9°c on the 8th     --      with a monthly mean of 14.0°c

  The 1 meter soil temp ranged from a low of 12.8°c on the 30th      to      a high of 14.3°c on the 9-11th     --     with a monthly mean of 13.7°c

   This makes the Jan' to September period of 2024 0.48°c warmer than the average for 2009-23 and with 126.3% of average rainfall for 2008-23

  Cumbrian Rainfall -- Drier further to the north and west; above average in the East

  After the contradictions and soakings of August, September was a much more benign month. However, across the county there were still some large variances in percentage totals.

  On the eastern fringes of the county rainfall totals were above average and by a fair margin. This saw Barras with 129.6 mm (159.6% of its LTA) record the highest percentage fall. Those percentages gradually decreased as we travelled west, down to 144.6% at Warcop, 137.9 mm at Appleby and then to 100% at Maulds Meaburn.

  And yet less than 50% was recorded at Seaton (Workington), but with the lowest total of just 47.2% found at Grasmere. The central portion of the LDNP running N-S from Keswick down to Ambleside and either side, was notably dry at around 50% of the LTA.

  However, the month still managed at least one very wet day. Within the LDNP it was the 14th when Ennerdale Black Sail notched up 102.8 mm in the 24Hrs, the second highest total of 88.6 mm coming at the gauge behind the Wasdale Inn.

  Outside of the LDNP the wettest day varied, but in the east it was broadly the 8th when even Kirkby Thore notched up 31.4 mm, but then at Barras it would be the 25th, although the 32.8 mm wasn't especially high.

  One curiosity about Barras recording the highest percentage fall is that rain was recorded on just 15 days, one of the lowest totals in the county and beaten by only a handful of sites with 14.