January 2023 was a little cooler and drier than usual and the average maximum temperature of 7.8°C was 0.3°C below the Usk average for January of 8.1°C. The minimum temperature sank below 0°C on nine days. The warmest day was the 10th (max = 12.2°C) and the coldest was the 21st with a maximum of 1.7°C.
The measured rainfall was 102.6 mm, 80% of the Usk* average for January of 127.6 mm. Rain was measured on 15 days in the month, the wettest being the 14th when 19.4 mm fell. The last 17 days had little measurable rain, the total being about 2 mm.
February 2023 was warmer than usual, and was much drier than usual also, being the third driest month since records began in April 2011. The month had eight frosty mornings, the coldest overnight being -2.2°C on the 6th. Overall, the average maximum temperature of 9.4°C was 0.9°C above the Usk average for February of 8.5°C with a maximum of 13.9°C on the 17th.
There were 21 days on which no significant rain (0.2 mm or less) fell, and a total monthly rainfall of 11.4 mm was 13% of the Usk* average for February of 87.4 mm. The wettest day was the 22nd with 2.6 mm.
March 2023 was much colder and wetter than usual. Overall, the average maximum temperature of 9.6°C was 1.5°C below the Usk average for March of 11.1°C. There have been three colder Marches since 2012, with the remarkably chilly March of 2013 being the coldest, with its mean maximum of only 5.4°C.
The coldest by day was the 9th, with a maximum of 2.8°C, and the warmest was the 30th with a maximum of 14.4°C. There were no days when the minimum fell below zero.
There were 25 days on which rain fell (>0.2 mm), the wettest being the 9th with 23.4 mm. The total rainfall of 156.0 mm was 88% above the Usk* average for March of 83.1 mm. This made it the second wettest March in Penallt since records began in 2011, with 2018 being the wettest (170.8 mm). This is nowhere near as high as the 302.1 mm recorded in Penallt in January 2014 however.
Despite appearances, the month was actually drier than it might have been given that, overall, Met Office data make March the wettest in Wales since 1981 with a nationwide average of 206.5 mm, 100% above usual.
April 2023 was wetter and much cooler than usual.
Overall, the average maximum temperature of 12.4°C was 1.6°C below the Usk average for April of 14.0°C with a peak of 19.1°C on the 29th. The minimum temperature was -1.7°C on the 4th and that was the sole day of air frost.
There were 16 days when no rain (or a trace) fell, the wettest day being 11th when 20.4 mm fell. It was wetter than usual overall with the total rainfall of 93.8 mm being 39% above the Usk* average for April of 67.5 mm.
May 2023 was drier than usual and saw 8 days on which significant rain fell. The total rainfall of 54.0 mm was 80% of the Usk* average for May of 71.5 mm. The vast majority of this rain fell between the 4th and the 11th with only 2.2 mm falling in the rest of the month.
Maximum temperatures exceeded 20°C on 7 days with a high of 21.5°C on the 18th. Although May ended with some cool days, the average maximum temperature of 18.2°C was 0.7°C above the Usk average for May of 17.5°C.
June 2023 was exceptionally warm and was much drier than usual too.
The average maximum temperature of 22.8°C was 1.5°C above the Usk* average for June of 20.3°C and there were 24 days when 20°C was exceeded, twenty of these being on successive days (7th to 26th inclusive). The maximum was 27.6°C on the 13th. This makes June 2023 the warmest on record in Penallt.
June had only 1 very wet day (> 10mm) and the Penallt total rainfall was 21.8 mm, 36% of the Usk* June average of 60.2 mm. The wettest day was the 20th, with a fall of 15.4 mm. There were 24 days in the month when no measurable rain fell too. Overall, this was the second driest June on record in Penallt, the driest being 2018 when 16.0 mm were recorded.
July 2023 was cooler and wetter than usual. The total rainfall of 95.6 mm was 53% above the Usk* average for July of 62.6 mm, making this the third wettest July since Penallt records began 12 years ago, the wettest being 2012 with a fall of 141.6 mm. There were 11 days on which no measurable rain fell.
The average maximum temperature of 20.0 °C was 2.3 °C below the Usk average for July of 22.3 °C; there was only one day when the temperature rose above 25 °C, this being the 7th (26.9 °C). The coldest day was the 4th (max of 14.2 °C).
July 2023 was the coldest July since Penallt records began 12 years ago, equal with the miserable July of 2012.
August 2023 was cool and of roughly average rainfall. The total rainfall of 74.8 mm was 1% above the Usk* average for August of 73.9 mm and there were 17 days on which no significant rain (>0.2 mm) fell. The wettest day was the 5th when 18.4 mm fell.
The average maximum temperature of 20.5 °C was 1.6 °C below the Usk average for August of 22.1 °C. The warmest day was the 10th (25.4 °C), the only day on which the temperature reached 25 °C.
The temperature on August 31st never rose above 14.8 °C, making it one of the coldest August days on record.
September 2023 was very warm overall and of about average rainfall too. The total rainfall was 72.7 mm, 90% of the Usk* average for September of 81.2 mm. There were 16 dry days (rainfall of 0.2 mm or below). The wettest day was the 20th, when 16.6 mm fell.
The month started with 11 consecutive days of maximum temperatures exceeding 20 °C and contained a mini-heatwave of seven days of 25+°C but was thereafter cooler than usual. Overall, the mean maximum temperature of 20.8 °C was 1.6 °C above the Usk average for September of 19.2 °C. The highest was 29.2 °C on the 9th and the lowest of 15.2 °C occurred on the 22nd. Some very warm nights occurred during the heatwave and there was a minimum overnight temperature of 19.6 °C on the 18th.
October 2023 was a little wetter than usual and was remarkably warm overall. The average maximum temperature of 15.5°C was 0.5°C above the Usk average for October of 15.0°C, whilst the average minimum of 9.3°C was a huge 2.9°C above the Usk average for October of 6.4°C. A warm spell early on saw the daily maximum rise above 20°C on the 7th, 8th and 9th, 22.7°C on the 9th being the highest.
There were twelve days on which no significant rain was recorded overall. The total rainfall of 143.5 mm was 14% above the Usk* average for October of 126.3 mm. The wettest day was the 18th when 19.6 mm rain was recorded.
Click the button below for an Excel file giving daily data for 2023:-
* Usk is the nearest Met Office station for which long term averages (1981-2010) are available.