2023 overview

[Weather data recording started in Penallt in March 2011. The charts below show the monthly summaries from January 2023 until the end of December 2023 and also compare Penallt’s 2023 weather with the 1981-2010 overall average data for Usk, the nearest place (16 km by crow) for which reliable data exist.]

Monthly maximum and minimum temperatures
The chart shows that Penallt monthly average maximum temperatures mirrored the long term averages for Usk pretty well overall (14.7°C as opposed to 14.8°C), with a warm June making up for below par July and August.

Penallt was clearly warmer by night overall (7.5°C as opposed to 5.7°C), perhaps due to temperature inversion effects. Interestingly, this happened on every month during the year.

  • September 9th was the warmest day of the year with a maximum of 29.2°C
  • December 2nd had the lowest maximum temperature of 0.4°C
  • Warmest by night was September 7th with a minimum of 19.6°C
  • Coldest by night was December 2nd, with a minimum temperature of -6.7°C
  • There were 78 days on which the temperature exceeded 20°C and 30 when it was below 0°C
  • The mean annual temperature was 11.3°C.

The mean annual temperature for England and Wales (1845 to 2012) is 9.3°C. The 2023 figure for Penallt is thus 2.0°C above the England/Wales average. The mean maximum temperature was 14.7°C (Usk = 14.8°C). Night times were much warmer than usual (mean min = 7.5°C, 1.8°C above that for Ross).

The chart below shows that 2023 was the second warmest year in Penallt since records started in April 2011.


The chart shows the usual uneven distribution of rainfall throughout the year. Four months had in excess of 100 mm falling, with December’s 199.4 mm being the wettest. By contrast, February was an untypically dry month (11.4 mm)

Overall, the total rainfall for 2022 was 1159.0 mm (45.6 inches), 7.6% above the average Usk total of 1076.9 mm (42.4 inches) showing that the year was a little wetter than average overall and making it the wettest year since 2020.

  • Rain was recorded on 229 days in the year
  • The wettest day was December 4th when 37.8 mm fell
  • 20 mm or more fell on 8 different days

July to December record rainfall?

The BBC reported that “for the UK as a whole, the period between July and December 2023 was the wettest on record (in a series from 1890).”

But the chart below shows that Penallt was an exception to this, with 2012, 2013, 2015, 2019 and 2020 all being wetter.

Further details

Much more information about month by month descriptions of weather in this year as well as the detailed daily data is available here.