Monthly summary & stats 2025

Davis Vantage Vue AWS at Gorwel Heights in Llanfairfechan.
Llansadwrn (Anglesey) Weather:
Monthly and Annual
Summary for 2025
Logo: Llansadwrn Weather - Melin Llynnon, Ynys Môn

Llansadwrn data table
Gorwel Heights data table
January
February

Winter

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

Wet and windy with storm Éowyn bringing record high gusts to Ireland, temperatures a little below averages

A wintry beginning with a very mild spell followed by storm Éowyn

Rainfall totalled 129.5 mm ranking as one of the 34 wettest Januaries in Llansadwrn since records began in 1928. Least since 2022 it was (105%) of the decadal average that had seen some very wet Januaries (180.6 mm in 2021), and [125%] of the somewhat drier 1991-2020 period average. The wettest day was on the 5th with 19.2 mm much falling as ice precipitation. There were 6 days with no precipitation (+1.9); 19 dry days (+2.2); 21 rain days (-2.2); 15 wet days (-1.1); and 9 (+1.0) with 5 mm, or more. At Gorwel Heights in Llanfairfechan rainfall of 136.0 mm (119%) & [153%] of averages was least since 2022, here the wettest day was on the 23rd with 30.6 mm while the 5th saw 30.4 mm. Here there were 8 dry days; 23 rain days; 17 wet days; and 7 had 5 mm, or more. Rainfall duration (wet hours) was 131 h at Gorwel heights and 128 h in Llansadwrn.

The mean temperature 5.0C in Llansadwrn (-0.7) & [-0.4[ of averages was lowest since 2021 and the 17th lowest in records since 1979. The mean maximum was 7.3C with the highest maximum 11.9C on the 16th and the lowest 2.0C on the 8th. The mean minimum was 2.6C with the lowest minima -2.2C on the 9th and -1.4C on the 10th resulting in 23.2 hours of frost the only two days of air frost recorded. There were 19 days of ground frost (+2.2) with the lowest -6.2C on the 9th. An air frost of -0.9C was also recorded at Gorwel Heights on the 9th with 6.5h of frost recorded. Here the mean minimum was 3.5C with the highest 10.5C on the 14th . The mean maximum was 8.0C with the highest 13.2C on the 14th and lowest 3.3C on the 8th. The mean 5.8C was (-0.8) & [-0.4] of averages was lowest since 2021.

Gorwel Heights had extreme wind speeds on the 24th for 3 hours between 0120 and 0410 GMT recording a high gust of 76 mph. At 0240 GMT a 10 min (height corrected) mean wind speed of 47 mph force 9 was recorded, likely responsible for blowing over a long length of brick wall. The highest gusts in Llansadwrn were 58 mph at 0220 GMT and 57 mph at 0740 GMT. Between 0220 and 1000 GMT 20 gusts of 50 mph, or more, were recorded. The wind resulted in the removal of several roof slates. This was the windiest spell recorded at the stations since before 2010.

February 2025

Quite a dry and sunny month with temperatures above the 30-y climatological averages

Area gales at the beginning and end of the month, little wintriness occurred and it was sunny at the end

A dry month the 55.8 mm of rainfall just (51%) of that received in the last 10 years, but was [62%] of the 1991-2020 average. Least since 2023 and ranking 37th lowest since 1928. The wettest day was on the 23rd when 14.6 mm fell. There were 8 (+1.5) days with no precipitation and 10 (+1.1) dry days. Rain days were 18 (-1.4); wet days 11 (-2.45); and only 4 days (-3.1) had 5 mm, or more. Gorwel Heights in Llanfairfechan was a little drier with 48.6 mm (52%) & [65%] of averages least since 2022, here the wettest day was on the 23rd with 13.8 mm while Gorddinog had a total of 59.8 mm with the most 14.8 mm. Rainfall duration (wet hours) was 58h at Gorwel Heights and 72h in Llansadwrn.

The mean temperature 6.5C (+0.2) & [+0.9] of averages was lowest since 2021, but was ranked 13th highest in records back to 1979. The mean maximum was 8.8C the highest 13.4 on the 20th and lowest 4.5C on the 13th. The mean minimum was 4.1C with the lowest 0.2C on the 14th that also had the lowest grass minimum of -4.2C. There was no air frost, but there were 10 days of ground frost. Gorwel Heights in Llanfairfechan had a mean temperature of 7.1C (+0.1) & [+1.2] of averages, lowest since 2021.. The mean maximum was 9.2|C with the highest 16.2C on the 20th and lowest 4.4C on the 10th. The mean minimum was 5.0C with the highest 11.8C on the 21st and lowest 1.6C on the 14th.

A high gust of 65 mph was recorded at Gorwel heights on the 23rd.

A sunny month at RAF Valley with 95.0h (provisional) highest since 2019 and ranking 19th on the Anglesey record since 1931. The sunniest day was the last day the 28th having 9.9h and there were 7 sunless days.

Winter 2024/25

Temperature close to decadal averages and above 30-y averages

Rainfall below decadal averages and above 30-y average

Winter seasonal averages		Anomalies
		10-y	30-y
Temperature (C)
Mean maximum	8.6	-0.1	+0.6
Mean minimum	3.9	0.0	+0.8
Mean	6.3	0.0	+0.7
Rainfall (mm)	358.9	88%	108%

Monthly data 2025

Llansadwrn (Anglesey): Monthly weather data summary for 2025
Anomaly ~ is based on the 2015-24average.
Anomaly 30-y is based on the 1991-2020 average.
													.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Air temperatures (C)
													.
Mean max	7.3	8.8											8.1
Mean min	2.6	4.1											3.4
Mean	5.0	6.5											5.7
Anomaly~	-0.7	0.2											0.2
Anomaly 30-y	-0.4	0.9											0.4
High max	11.9	13.4											13.4
Date	16	20											.
Low max	2.0	4.5											2.0
Date	8	13											.
High min	7.9	10.4											10.4
Date	8	21											.
Low min	-2.2	0.2											-2.2
Date	9	14											.
Grass min	-6.2	-4.2											-6.2
Date	9	14											.
													.
MSL Pressure at 09 GMT (mb)	1011	1019											1015
Highest	1037	1045											1045
Date	12	6											.
Lowest	969.5	993.9											969.5
Date	27	21											.
													.
Means at 0900 GMT													.
Air temperature (C)	4.3	5.7											5.0
Dew point (C)	3.3	4.5											3.9
RH%	94	92											93
Soil temperatures (C)													.
													.
5 cm	3.7	5.4											4.6
10 cm	4.1	5.3											4.7
20 cm	4.5	5.5											5.0
30 cm	5.5	6.2											5.9
Anomaly~	-0.5	-0.1											-5.8
50 cm	6.3	6.7											6.5
100 cm	7.5	7.3											7.4
Anomaly~	-0.3	-0.2											-4.5
													.
Rainfall (mm)													.
													.
Rain tot	129.5	55.8											185.3
Rain % ave~	105	51											14
Rain % 30-y	125	62											16
Days 0.0	6	6											12
Days <0.2	10	10											20
Days >=0.2	21	18											39
Days >=1.0	15	11											26
Days >=5.0	9	4											13
Max fall	19.2	14.6											19.2
Date	5	23											.
Highest rate (mm/h)	25	33											33
Date	30	19											.
Average rain per hour (mm)	1.0	0.8											0.9
													.
Evaporation													.
													.
Piche (mls/ mm)	23.2	23.7											46.9
Lysimeter PE (mm)	13.5	18.7											32.2
AWS ET calculated	30.0	19.2											49.2
													.
Weather (days)													.
													.
Air frost	2	0											2
Ground fr	19	10											29
Sl/snow	4	0											4
Sn lying	1	0											1
Thunder	0	0											0
Hail <5 mm	8	1											9
Hail >=5 mm	0	0											0
Fog at 09h	0	0											0
Gales in SE Anglesey	2	4											6
													.
Wind direction at 09h (days)													.
													.
N	2	1											3
NE	2	4											6
E	2	6											8
SE	6	1											7
S	2	7											9
SW	10	4											14
W	2	4											6
NW	3	0											3
Calm	2	1											3
													.
Wind speed mph													.
													.
Daily mean	5.3	6.4											5.9
Highest daily mean	21.5	17.7											21.5
Date	24	23											.
Mean gust	20.7	20.9											20.8
Highest gust	58	52											58
Date	24	21											.
													.
AWS records of rainfall and frost													.
													.
Wet hours (with 0.2 mm,or more)	128	72											200
Frost duration (h)	23.2	0											23.2
													.
Cloud cover at 09h. Mean %	81	75											78
													.
Global solar radiation (MJ m-2)													.
													.
Llansadwrn
Sol rad mean	2.25	5.87											4.06
Maximum	4.47	13.96											13.96
Date	25	28											.
Minimum	0.84	1.29											0.84
Date	21	11											.
Brightest hour W/sq m	291	477											477
during hour beginning GMT	12	12											12
on day	29	28											.
Sunless days	11	8											19
													.
Sunshine (h)													.
[ ~ missing days are derived]													.
Valley	55.4	95.0											150.4
Average %~	103	116											10
Average 30-y	98	121											10
Sunniest	7.3	9.9											9.9
Date	21	28											.
Sunless days	11	7											18
													.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year

Llanfairfechan, Gorwel Heights observations

Gorwel Heights (73 m), Llanfairfechan (Conwy): Monthly weather data summary 2025
Anomalies based on 30-y [1991-2020] # & 10-y averages (2015-2023) *
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Air temperatures (C)
													.
Mean max	8.0	9.2											8.6
Mean min	3.5	5.0											4.3
Mean	5.8	7.1											6.4
Anomaly (2015-2024) *	-0.8	0.1											-5.1
Anomaly [1991-2020] #	-0.4	1.0											-4.2
High max	13.2	16.2											16.2
Date	14	20											.
Low max	3.3	4.4											3.3
Date	8	10											.
High min	10.5	11.8											11.8
Date	14	21											.
Low min	-0.9	1.6											-0.9
Date	9	14											.
													.
MSL Pressure at 09 GMT (mb)	1011	1020											1016
													.
Highest	1038	1046											1046
Date	12	6											.
Lowest	969	993											969
Date	27	21											.
													.
Means at 0900 GMT
Air temperature (C)	5.2	6.9											6.1
Dew point (C)	2.3	3.9											3.1
RH%	82	81											82
													.
Rainfall (mm)
													.
Total	136.0	48.6											184.6
% (2015-2024) *	119	52											14
% [1991-2020] #	153	65											17
Max fall	30.6	13.8											30.6
Date	23	23											.
Highest rate (mm/h)	43	27											43
Date	23	4											.
													.
Wet hours (with 0.2 mm, or more)	131	58											189
Average rain per hour (mm)	1.0	0.8											1.0
													.
Days <0.2	8	12											20
Rain >=0.2	23	16											39
Wet >=1.0	17	9											26
Days >=5.0	7	5											12
													.
Weather (days)													.
													.
Air frost	1	0											1
Frost duration (h)	6.5	0											6.5
Wind direction at 09h (days)													.
													.
N	1	1											2
NE	1	5											6
E	1	3											4
SE	7	5											12
S	3	4											7
SW	5	7											12
W	2	0											2
NW	3	0											3
Calm	8	3											11
													.
Mean mph	3.9	6.3											5.1
Highest daily mean mph	13.2	20.6											20.6
Date	24	23											.
Mean gust	22.0	25.4											23.7
Highest gust	76	65											76
Date	24	23											.
													.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year

Acknowledgements

The Met Office at RAF Valley kindly supplied observational data from 1942 to 2011. Current data (provisional) are gathered from SYNOP reports and METAR, final data from the Met Office website. I am grateful to David Lee for use of his data from Gorddinog.

Page first dated 5 February 2025
llansadwrn-wx.info

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