Llansadwrn (Anglesey) Weather:
Monthly and Annual
Summary for 2025

• Llansadwrn data table
• Gorwel Heights data table

• January
• February
• Winter
• March
• April
• May
  • Spring
• June
• July
• August
  • Summer
• September
• October
• November
  • Autumn
• December

• Annual
  
  
• Acknowledgements

• Llansadwrn data table
• Gorwel Heights data table

   

  Note: Values in (.) refer to the 10-y 2015-2024 average; [.] refer to the 30-y 1991-2020 climatological average while {.} refer to the station's different LTA (long-term averages). All data are subject to verification and amendment. Javascript must be enabled to see the pop-up graphics, as of date this works best with Firefox and. Chrome browsers..

  

January 2025

February 2025

Warmest April on record in Llansadwrn. Absolute maximum second highest on record.

The mean maximum temperature 12.0C was highest in my station records going back to 1979, (+2.8] & [+2.9] of averages. The mean maximum was 16.5C (+3.4) & [+3.7] of averages, with the highest maximum 25.1C on the 30th, just behind the station's highest April temperature 25.3C (+4.8) recorded on the 16th of the month in 2003. The lowest maximum was 10.6C (+2.4) on the 15th. The mean minimum 7.5C [(+2.1)] was highest since 2011, the highest 12.2C on the 30th and lowest 2.3C on the 17th that also saw the lowest grass minimum of 0.0C so there was no frost in the month.

The mean temperature at Gorwel Heights, Llanfairfechan, was 12.2C, highest since 2011 when 12.6 was recorded. The mean maximum was 16.1C The highest maximum was 21.6C on the 30th and the lowest 9.8C on the 15th. The mean minimum was 8.3C with the highest 11.7C on the 29th and 30th, the lowest minimum was 5.6C on the 17th.

It was a relatively dry month with 41.3 mm rainfall, lowest since 2022 ranking 27th in Llansadwrn records back to 1928. Rainfall since January totals 246.7 mm, lowest since 2010, largely made up of the 129.5 mm that fell in January.. The largest fall in April was 12.8 mm on the 14th. There were 18 days (+4.7) with no precipitation; 19 (+3.2) dry days; 11 (-3.2) rain days; 8 (-2.1) wet days; and 3 days (-0.7) had 5 mm, or more.

Rainfall at Gorwel Heights was 49.0 mm, least since 2022, with the largest fall 12.6C on the 15th. There were 20 dry days; 10 raindays; 6 wet days; and 4 days had 5 mm, or more. Rainfall duration was 69 hours while Llansadwrn had 71 hours.

It was a sunny month at RAF Valley with a provisional 232h, most since 2021, the third sunniest April on the Anglesey record back to 1931. . There were 3 sunless days and the sunniest was on the 30th with 13.9h.

Sunny with above average temperatures and below average rainfall

At Gorwel Heights in Llanfairfechan rainfall was 47.4 mm (63%) & [62%] of averages least since 2023. The wettest day was on the 27th with 19.4 mm. Dry days were 25; rain days 6 ; wet days 6; and 3 had 5 mm, or more. Rainfall duration (wet hours) was 46 hours.

The mean temperature was 13.3C (+1.1) & [+1.6] of averages, highest since 2023 ranking 4th highest in station records since 1979. The mean maximum was 17.7C rank 4 with the highest 24.2C on the 1st and lowest 12.6C on the 27th. The mean minimum was 9.0C rank 7 highest with the highest 13.6C on the 30th and lowest 4.2C on the 6th. Lowest grass minimum was 2.2C (+2.1) on the 3rd. No frost in the month.

At Gorwel Heights the mean temperature was 13.7C , lowest since 2023, (+0.8) & [+1.2] of averages. The mean maximum was 17.3C =highest since 2017. The highest maximum on the 30th was 22.9C, highest since 2021, the lowest 11.9C on the 5th. The mean minimum was 10.1C with the highest 14.8C on the 30th and lowest 6.3C on the 5th.

Sunshine at RAF Valley was 317.32h (MetO provisional figure) the sunniest May on the Anglesey record. There was just one sunless day on the 26th while the sunniest with 14.9h was on the 16th.

June 2025

Temperatures and rainfall well above averages, rather dull less sunshine than usual.

Rainfall of 125.0 mm, (179%) and [169%] of averages, was largest since 2017 and ranked 9th in Llansadwrn records back to 1928. The wettest day was on the 2nd having 24.4 mm not quite making the 1 inch in old money. Five days exceeded 10 mm with 8 days (+3.6) 5 mm, or more. There were, however, 5 days (-6.1) with no precipitation while there were 9 dry days (-6.6). Rain days were 21 (+6.1) and wet days 16 (+5.3). Rainfall duration was 119 wet hours with an average of 1.1 mm falling per hour.

It was drier at Gorwel Heights, Llanfairfechan, with 74.6 mm (118%) & [105%] of averages, largest since 2020. The wettest day was on the 2nd with 12.0 mm. Dry days were 15; rain days 15; wet days 13 and 8 had 5 mm, or more. Rainfall duration was 89 wet hours with an average of 0.8 mm falling per hour.

The mean temperature in Llansadwrn was 15.6C (+0.8) & [+1.5] of averages, highest since 2023 ranking 4th highest in station records since 1979. The mean maximum was 18.9C with the highest 27.9C on the 20th and lowest 13.2C on the 20th. The mean minimum was 12.2C with the highest 17.4C on the 20th and lowest 6.1C on the 8th. The lowest grass minimum was 3.4C on the 8th. Eight days had 20C, or more with a spell of 4 days 18-21st.

The mean temperature at Gorwel Heights was 16.9C highest since 2023. The mean maximum was 20.7C with the highest 28.9C on the 20th and lowest 13.2C on the 7th. The mean minimum was 13.0C with the highest 18.3C on the 21st and lowest 7.9C on the 7th.

Thunder dust and thunder bees. Thunder was heard on the 14th between 0450 and 0550 GMT. Ice pellets and a trace of Saharan dust were recorded along with a swarm of an estimated 20-30,000 bees just before 0900 GMT. The sound of them flying around the weather station for an hour was remarkable, observations were completed as usual, when they later settled down on a conifer bush they became quite tranquil. A local beekeeper collected them and installed them in a hive, that they filled, in his garden . When I passed the hive on a sunny day a few days later the bees were humming nicely, no doubt stocking up with nectar from abundant flowers at this time of year in our garden.

A rather dull month with RAF Valley provisionally reporting 167.5 h. The sunniest day was on the 19th having 14.2h and there were 2 sunless days.

Fairly dry, warm and sunny month.

Rainfall was 54.8 mm (58%) & [71%] of averages least since 2022 and ranked one of the 29 lowest July falls in Llansadwrn records since 1928. Two days had 10 mm, or more, the wettest on the 15th had 13.0 mm and the 14th had 12.2 mm both adding up to nearly an inch in old money. Twelve days (+3.0) had no precipitation recorded in the official copper gauge, but the AWS black plastic gauge on the ground, in standard position, recorded 5 days with 0.2 mm, or more, precipitation the result of heavy dew formation. There were 16 dry days (+3.2); 15 rain days (-3.2); 11 wet days (-2.8); and 3 days (-3.7) had 5 mm, or more.

Rainfall at Gorwel Heights, Llanfairfechan, totalled 46.8 mm (48%) & [59%] of averages, least since 2022, second lowest on record since 2011. There were 9 dry days; 22 rain days; 11 wet days; and 3 days had 5 mm, or more. The wettest days were the 15th with 13.0 mm and 14th with 5.0 mm the same as Llansadwrn.

The mean temperature at Llansadwrn was 17.3C (+1.3) & [+1.5] of averages, highest since 2018 ranking 7th highest in station records since 1979. The highest mean was 23.6C on the 12th and the lowest 14.3 on the 2nd, apart from the 14.6C on the 15th all reached 15C, or more. The mean maximum was 21.0C equal highest since 2021 ranking 11th. The highest maximum was 30.6C on the 12th and the lowest 15.9C on the 1st. Sixteen days reached 20C, or more. The mean minimum 13.6C was 2nd highest on record with 2006 just 13.8C the highest since 1979. The lowest minimum was 8.8C on the 2nd the only sub 10C in the month.

At Gorwel Heights the mean temperature was 17.9C [(+1.3)] of averages, highest since 2022. The mean maximum was 21.3C with the highest 32.2C on the 12th. Four days reached 25C, or more, while 19 days reached 20C, or more. The mean minimum was 14.6C, highest on record, with the highest 19.9C on the 13th and lowest 10.6C on the 2nd. No days were sub 10C.

It was a sunny month with RAF Valley provisionally recording 199.9h sunshine, lowest since 2022 ranking 33rd on the Anglesey record since 1931. Sunniest was the 11th having 15.4h and no sunless days were recorded.

Solar radiation in Llansadwrn on the essentially cloudless and clear 11th, 12th and 13th was 28.22, 28.22 and 28.07 MJ m ^-2 respectively.

August 2025

Warm, sometimes hot, sunny and quite dry

Temperatures were once again well above the averages with the mean 17.5C (+1.5) & [+1.9] highest since 1997 ranking 3rd in station records since 1979. The mean maximum was 21.6C (+2.4) & [+2.7] of averages with the highest 30.6C on the 12th. There were three hot days (>=25C), the 12th 13th and 16th. There were 21 warm days (>=20C), the longest spell was 5 days 6-14th. The lowest maxima were on the 20th and 28th with 17.2C (+2.1). The mean minimum was 13.4C (+0.7) & [+1.1] of averages, the highest was 16.8C (+0.3) on the 13th and the lowest 9.4C (+0.6) on the 21st that also had the lowest grass minimum temperature of 6.1C (+0.8).

Temperatures at Gorwel Heights, Llanfairfechan were above averages with the mean 18.2C (+1.4) & [+1.5], equal highest with 2022 on record (15 years). The mean maximum was 21.9C (highest on record) with the highest 30.3C on the 12th. There were 5 hot days and 25 warm days with a spell of 14 days 2-18th. The mean minimum was 14.5C (second highest on record). The highest minimum was 16.8C on the 4th and the lowest 11.4C on the 2nd was highest on record.

Rainfall in Llansadwrn was 49.5 mm (51%) & [55% of averages, least since 2003 and ranked the 14th lowest since records began in 1928. The wettest day was on the 31st with 12.8 mm. Days with no precipitation numbered 13 (+5.2) and dry days were 19 (+5.8). Rain days were 12 (+5.8); wet days 5 (-5.0); and those with 5 mm, or more, were 4 (-1.0). Rain duration (wet hours) was 56 h.

Rainfall at Gorwel Heights was 43.0 mm (42%) & [49%] of averages, lowest on record (15y). The wettest days was was on the 31st with 18.2 mm. Dry days were 23; rain days 8; wet days 7; and 3 days had 5 mm, or more. Rainfall duration (wet hours) was 39 h.

Sunshine at RAF Valley was 225 h (127%) & [ 138%] (provisional), highest since 2022 ranking 11th on the Anglesey record The sunniest day was on the 17th with 12.4h, there were no sunless days

Summer 2025

It was the warmest summer on record in Llansadwrn since before 1979.

September 2025

First month of the year since January to have below average temperatures. Rather wet, but fairly sunny.

Sunny in the first and last quarters of the month. Rather wet in the middle

Temperatures were a little below average for the first timesince January. The mean temperature 13.8C, equal lowest since 2015, was (-0.6) & [-0.2] of averages. The mean maximum 17.0C was (-0.7) & [-0.3] of averages and ranked 27th highest in station records since 1979. The highest maximum 21.8C on the 6th was (-1.9) and the lowest 12.4C on the 20th (-0.5). The mean minimum was 10.7C with the highest 16.3C on the 7th and lowest 6.5C on the 22nd. There was no frost and the lowest grass minimum was 3.9C on the 22nd.

At Gorwel Heights, Llanfairfechan, temperatures again were a little below the averages for the first timesince January. The mean 14.9 was (-0.3) & [-0.1] of averages. The mean maximum was 18.0C with the highest 23.6C on the 6th and the lowest 12.8C on the 20th. The mean minimum was 11.7C with the highest 15,8C on the 7th and the lowest 7.5C on the 22nd.

Rainfall in Llansadwrn was 178.2 mm least since 2022 and (149%) & [176%] of averages. The wettest day was on the 20th with 46.5 mm following 23.5 mm on the 19th. Another wet day was on the 16th when 37.8 mm fell. Six days had no precipitation (-1.9) and there were 11 dry days. Rain days were 19; wet days 15; and 9 days had 5 mm, or more. Rainfall duration (wet hours) totalled 126 h, the 19th had 19 hours and the 20th 17 wet hours in the 24 hours.

Rainfall at Gorwel Heights totalled 160.6 mm (130%) & [168%] of averages. The wettest day was on the 20th with 50.3 mm while the previous day the 19th had 27.0 mm. The 16th another wet day had 22.0 mm. Here dry days were 11; rain days 19; wet days 16; and 7 days had 5 mm, or more. Rainfall duration was 111 wet hours.

October 2025

Fairly dry with near average temperatures, record low Anglesey sunshine

Very wet at the beginning, much cloud and fog at times many sunless days

October was fairly dry as Octobers go these days. The 96.5 mm was most since 2023 (70%) & [75%] of averages, ranking 34th lowest in Llansadwrn since 1928 The most 23.5 mm fell on the 3rd following 12.0 mm on the 2nd. Two other falls reached 10 mm, or more, 10.0 mm on the 25th and 11.5 mm on the 31st. Eight days had no precipitation and there were 11 dry days. Rain days were 20 and wet days 15. Rainfall duration (wet hours) totalled 121, the average rain per hour was 0.8 mm.

The mean temperature 11.1C (-0.5) & [0.0] of averages, lowest since 2020 ranking 20th lowest since 1979. The mean maximum was 13,8C with the highest 17.6C on the 6th (-1.8). The mean minimum was 8.5C, the highest 13.8C was on the 2nd and the lowest 4.3C on the 26th. The lowest grass minimum was 1.3C on the 30th.

Rainfall at Gorwel Heights, Llanfairfechan, was 87.6 mm (62%) & [70%] of averages, least since 2017. The greatest fall 14.8 mm was on the 3rd while 10.4 mm fell on the 25th and 14.0 mm on the 31st. There were 14 dry days, 17 rain days; 16 wet days and 5 days reached 5 mm, or more. Rainfall duration (wet hours) totalled 108 h, the average rain per hour was 0.8 mm.

The mean temperature at Gorwel was 12.0C (-0.4) & [+0.1] of averages, lowest since 2020. The highest maximum was 21.1C on the 6th and the lowest minimum was 5.7C on the 13th.

Sunshine at RAF Valley (provisional) was 41.5h (44%) & [43%] of averages an average of 1.3h per day least in any month this year so far. Sunniest was the 29th with 6.2h and there were 13 sunless days.. It was the least October sunshine on the Anglesey record back to 1931.

November 2025

A very wet month with above average temperatures and low sunshine

Several spells of wet weather through the month

Rainfall in Llansadwrn was 221.8 mm (156%) & [167%] of averages most since 2015 and the 5th largest since 1928. The largest fall was 31.2 mm on the 30th with two other notable falls on the 12th 26.2 mm and 14th 25.6 mm. After the dry beginning to the year the soil took a while to become saturated, but did so by the end of the month. Despite the wetness there were 3 days with no precipitation recorded. There were 5 (-2.8) dry days; 25 (+2.5) rain days; 21 (+3.7) wet days; and 15 days (+5.8) had 5 mm, or more. Rainfall duration (wet hours) was 210 h, there were some thoroughly wet days with 22 h on the 14th; 15 h on the 12th and 30th; and 12 h on the 29th. Average rainfall per hour was 1.4 mm matching that in wet September highest of the year.

Autumn 2025

Wettest since 2018 the 496.5 mm (146%) & [137%] of averages ranked 7th wettest in Llansadwrn records since 1928.

Temperatures a little below the station decadal averages, but a little above the 30y averages.

December 2025

A warm, sometimes wet, sometimes dry and occasionally windy month.

Particularly windy in the middle of the month with a wet first half and a cooler sunnier and drier end

Rainfall was 156.5 mm (90%) and [115%] of averages lowest since 2019, but one of the 22 wettest Decembers in Llansadwrn since 1928. The wettest day was on the 1st having 24.4 mm. There were 9 days mostly in the second half of the month with no precipiation (+6.4). Dry days numbered 11 (+5.3); rain days were 20 (-5.3); wet days 17 (-3.2); and days with 5 mm, or more, were 10 (-0.6). Rainfall duration (wet hours) was 145 h.

At Gorwel Heights rainfall was 129.4 mm (77%) & [104%] of averages, lowest since 2019, fourth driest since 2011. The wettest day was on the 1st having 20.2 mm. Thre were 10 dry days; 21 rain days; 15 wet days; and 10 had 5 mm, or more. Rainfall duration (wet hours) was 120 h. Gorddinog reported 131.8 mm and Valley 141.6 mm

The mean temperature in Llansadwrn was 7.3C about average based on the last 10-years (+0.3) average, but a huge [+1.6] based on the climatological average (1991-2020) the result of global heating ranking 8th highest in station records since 1979. The men maximum was 9.3C with the highest 15.0C on the 9th and lowest 5.0C on the 29th. The mean minimum was 5.3C (+0.6) & [+1.8] of averages ranked 6th highest in records. The lowest minimum was -0.2C on the 31st giving just one day of air frost. There were 6 nights with ground frost, lowest -3.3C on the 31st.

No air frost was recorded at Gorwel Heights where the mean minimum temperature was 6.5C with the lowest 1.6C on the 31st. the highest minimum was 11.3C on the 9th. The mean maximum was 10.2C average for the last decade with a highest a modest 17.3C on the 9th lowest since 2021 with record highest 19.3C).

Sunshine at RAF Valley was 62.5 h (provisional) highest since 2008, the 10th sunniest December on the Anglesey record since 1931 (183%) & [140%] of averages. The sunniest day was on the 27th having 11.3h of bright sunshine, there were 11 sunless days mostly in the first half of the month.

It was very windy in Llanfairfechan at Gorwel Heights on the 9th when a mean wind speed (mws) of 21.3 mph and a gust of 64 mph was recorded. There were several reports of damage to property in the area. Other windy days were the 1st (mws 12.1 mph); 5th (mws 12.2 mph); 11th (mws 14.3 mph); 14th (mws 18.0 mph); and 17th (mws 12.8 mph). Gorddinog had peak gusts of 70 mph on the 5th and 67 mph on the 9th.