View from the Rear Window - December 2023

 "December, being the last month of the year, cannot help but make us think of what is to come" - Fennel Hudson

The cold weather that ended November 2023 continued into December for a few days (Photo 1) before slowly warming up. The second half of the month was warm for this time of the year (Photo 2) though glimpses of sunshine were at a premium. Rain was certainly not in short supply and fell, mainly, at the start and end of the month. The winter flowering cherry added some welcome glamour to the garden scene.

Photo 1: A cold frosty morning (2nd December 2023)

Photo 2: Boxing Day 2023

A quick overview of the garden in December can be seen in the time lapse video (Video 1) below:

Video 1: Daily Garden Photos (December 2023)

While preparing the time lapse video, Clipchamp gave an option to produce an AI-generated video. Provided with the same daily photos, Video 2 was the end result. Better production values for sure but not as informative in my opinion.

Video 2: AI-generated Video of Daily Garden Photos

Summary of Weather Parameters for December 2023

Overall, a warm, cloudy and wet month with some sharp frosts at the beginning. Quite windy with a top speed of 61 km/h on the 28th December during Storm Gerrit.

Table 1: Weather Stats for December 2023

December 2023

Weather Parameter

Value

Dates

Average Monthly Temperature 

5 oC


Maximum Monthly Temperature

15 oC

23rd

Minimum Monthly Temperature

-7 oC

18th

Number of Air Frost Days

6


Number of Hot Days (> 25 oC)

0


Monthly Precipitation

75.0 mm


Greatest 24 h Precipitation

17.6 mm

3rd - 4th

Number of Dry Days

10


Monthly Sunshine Hours (estimated)

39



Average Wind Speed

5 km/h


Highest Wind Speed

61 km/h

28th

Maximum Barometric Pressure (Sea Level)

1039.6 hPa

21st

Minimum Barometric Pressure (Sea Level)

983.9 hPa

2nd

Average Barometric Pressure (Sea Level)

1010.9 hPa


Heating Degree Days

325.5


Cooling Degree Days

0.0



December's daily minimum & maximum temperatures are plotted out in Figure 1. The first half of the month was cold then cooler; the second half was balmy for December in England (even at night) which was just barmy.

Figure 1: Daily Min/Max Temperatures for December 2023

Daily rainfall and sunshine hours (estimated) for December 2023 are displayed in Figure 2. Most of the rain at the start and finish of the month with limited sunshine due to cloudy skies. On the plus side, the clouds ensured the nights stayed reasonably warm (Figure 1).

Figure 2: Daily Rainfall & Sunshine Data for December 2023

This month, for the first time, we can compare five December months from 2019 to 2023. There are a few trends beginning to show in the temperature data (Figure 3) although it is far too early to be sure without a longer time series. However, there is a discernible upward trend in the maximum December temperatures and a discernible downward trend in the minimum temperatures. Combined these two trends lead to slightly cooler mean (average) monthly temperatures. Significantly colder minimum temperatures have been experienced during the last two Decembers compared with the norm for 2019 - 2021. This may (I repeat may) be due to changes in atmospheric and ocean circulations, brought about by climate change, that result in colder winds from the north rather than warmer winds from the west during the English winter. Of course, it is far too early to tell and much more data are needed. It is worth remembering that climate change is not always intuitive (global warming does not mean everywhere gets warmer). However, there is no need to panic at the moment! Well, not until we get the data from next December!!!

Figure 3: December Temperature Data for the 2019 - 2023 Period

Rain, wind and sunshine data for the past five Decembers are summarised in Figure 4. The amount of rainfall in December is variable, sunshine levels are fairly constant (small decrease?) while maximum wind speeds are on an upward trend (possibly?!). Note that climate change is measured over much longer periods, typically 30 years, so these shorter time series are only indicative of trends that may or may not be sustained in the future. Time will tell!

Figure 4: December Rain/Wind/Sun Data for the 2019 - 2023 Period

The UK Met Office report for December 2023 can be found here. From this report (Figure 5) we learn that December 2023 was warm or very warm for England, Wales and Northern Ireland with Scotland about average. There were some very warm spots in south Herefordshire (Figure 5) though not in Hereford itself.

Figure 5: UK Mean Temperature Anomalies (December 2023)

Rainfall distribution for the UK is shown in Figure 6 indicating Herefordshire had higher than normal amounts of rain. The nearby Met Office weather station at Credenhill reports an average (1991 - 2020) rainfall for that location of 72.67 mm; close to the 75 mm reported by my Davis Weather Station (Table 1) for December 2023. Hereford City often reports lower rainfall than the surrounding rural environment - possibly due to its location between the Welsh Hills to the west and The Malverns to the east.

My weather station, located in an urban garden, may also be in a rain shadow surrounded as it is by dense housing. A colleague from the River Wye citizen science project I help out with, consistently measures higher rainfall amounts than my weather station despite living only a kilometre south of me. The Met Office weather station at Ross-on-Wye reported 130.6 mm of rain for December 2023 (against a December average of 80.14 mm).

Figure 6: UK Rainfall (% relative to 1991-2020 mean) - December 2023

The Met Office and I both agree there was a lack of sunshine in December - though I'm not sure the picture was as black as the Met Office (Figure 7) painted it - at least not for Hereford City. Perhaps that rain shadow has a silvery sunny lining!


Figure 7: UK Sunshine (% relative to 1991-2020 mean) - November 2023

Jobs in the Garden
  • Harvesting carrots, beetroot, parsnip, celeriac, cauliflower and red cabbage
  • Using up stored vegetables (tomatoes, garlic, Jalapeno peppers, potatoes, green beans, courgettes, celery, onions) and fruit (raspberries, gooseberries, blackcurrants, redcurrants, pears)
  • Composting jobs - hot composting with a single HotBin throughout winter - layering finished garden compost on fruit trees/bushes and vegetable plots.
Flora & Fauna (seen in the Garden)
  • 4 x Blackbirds
  • 5 x Blue Tits
  • 2 x Collared Doves
  • 1 x Dunnock
  • 1 x Great Tit
  • 10 x House Sparrows
  • 5 x Long-tailed Tits
  • 2 x Magpies
  • 2 x Robins
  • 6 x Starlings
  • 3 x Wood Pigeons

And finally, some December garden photos ...

Photo 3: Frozen Bird Bath (1/12/23) 

Photo 4: Frosted Swiss Chard (2/12/23)

Photo 5: Frosted Spider's Web on Weather Station (2/12/23)

Photo 6: Ice Crystals on Rosehips (2/12/23)

Photo 7: Red Cabbage and Cauliflower (9/12/23)

Photo 8: Last of the Fresh Tomatoes from the 2023 Kitchen Garden (11/12/23)

Photo 9: Winter Solstice 2023 Half Moon from the Garden (Pixel 7 Pro)

Photo 10: Starling in Flight over the Bird Feeder (31/12/23)


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