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Climate in Cemaes · Met Office 1991–2020 averages

Few UK towns get fewer frosts than Cemaes

Peak summer warmth arrives in July, with afternoons near 18.2°C (65°F). Seasons differ by 15°C, from the coldest nights to the warmest afternoons. Summers stay cool: July afternoons here are cooler than in 98% of UK towns. If you like long walks, July and August offer highs of 18°C.

July afternoons: cooler than 98% of UK towns
January nights: milder than almost every UK town
Rain a year: wetter than 77% of UK towns

Met Office 1991–2020 averages for the town itself.

A year in Cemaes at a glance

Each month’s typical high and low, in °C.

Jan8°C4°C
Feb8°C4°CColdest nights
Mar10°C4°C
Apr12°C6°C
May14°C8°C
Jun17°C11°C
Jul18°C13°C
Aug18°C13°CWarmest
Sep17°C11°C
Oct14°C9°C
Nov now11°C7°CWettest
Dec9°C5°C
A normal year

What a year in Cemaes feels like

Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.

Winter
9°C / 4°C
48°F / 39°F · 11 air frosts a year
Spring
12°C / 6°C
53°F / 43°F · 193 mm of rain
Summer
18°C / 12°C
64°F / 54°F · 1 days of 25°C+ a year
Autumn
14°C / 9°C
57°F / 48°F · 315 mm of rain, the wettest season
Best months to be outsideJulAugHighs of 17–27°C (63–81°F) and nights of 8°C (46°F) or more
Rain

About 981 mm of rain a year

November is the wettest month and May the driest. About 26 days a year bring 10 mm (0.4 in) or more.

981 mm
Rain a year (39 in)
Wetter than 77% of UK towns
26
Days a year with 10 mm of rain or more
1,575 hrs
Sunshine a year at Valley (Anglesey)
12 miles away

Rain by month

Millimetres

132 mm
JFMAMJJASOND

Sunshine by month

Hours of bright sunshine at Valley (Anglesey)

219 h
JFMAMJJASOND
Frost & warm days

11 air frosts and 1 days of 25°C a year

On about 11 nights a year the air drops below freezing; days that stay below freezing are rare. About 1 days a year reach 25°C (77°F).

11
Air frosts a year (below 0°C)
Fewer frosts than almost every UK town
0
Days that stay below 0°C
1
Days of 25°C (77°F) or more
Fewer warm days than 97% of UK towns

Day counts are 1991–2020 averages from the Met Office’s 2 km grid. The Met Office calls a day of 25°C or more a summer day and a night below 0°C an air frost; ground frosts, on grass, come more often.

Weather station

The Met Office station at Valley (Anglesey)

Valley (Anglesey) is 12 miles south of Cemaes, 10 m (33 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full.

MonthHighLowRainAir frostsSun (hours)
January8.4°C3.8°C75 mm5.258
February8.4°C3.6°C62 mm4.881
March9.8°C4.5°C57 mm2.4126
April12.1°C6.1°C54 mm0.5173
May15.0°C8.6°C52 mm0.0219
June17.2°C11.0°C57 mm0.0203
July18.8°C12.9°C58 mm0.0190
August18.8°C13.1°C69 mm0.0176
September17.3°C11.6°C74 mm0.0143
October14.3°C9.2°C102 mm0.1101
November11.3°C6.6°C104 mm0.759
December9.1°C4.4°C94 mm4.246
Year13.4°C8.0°C857 mm181,575

Met Office historic station data, Valley, 1991–2020 months averaged (a month needs 20 of the 30 years; estimated values counted, missing months left out). Sunshine: Kipp & Zonen recorder.

Compared with other towns

How Cemaes compares

Against the 2,537 towns and cities of 2,500 or more across the UK, each with its own Met Office averages, and its place among Gwynedd towns that size.

July afternoons18.2°C (65°F)
Cooler than 98% of UK towns
January nights3.9°C (39°F)
Milder than almost every UK town
Rain a year981 mm (39 in)
Wetter than 77% of UK towns
Air frosts a year11 nights
Fewer frosts than almost every UK town
Days of 25°C or more1 days
Fewer warm days than 97% of UK towns
Next door

Nearby towns’ climate

The nearest towns of 1,000+ within 12 miles: a hill, a valley or the sea can make a real difference over a few miles.

TownJuly highJanuary lowRain a year
Cemaes18.2°C3.9°C981 mm
Amlwch 4.5 mi18.1°C about the same3.6°C about the same1,051 mm
Llanerchymedd 6.5 mi18.4°C about the same3.1°C 0.8°C colder1,087 mm
Bodedern 8.5 mi19.1°C 0.9°C warmer3.4°C about the same980 mm
Valley 9.8 mi19.0°C 0.8°C warmer3.8°C about the same893 mm
Holyhead 10.4 mi19.0°C 0.8°C warmer4.1°C about the same872 mm
Benllech 11.2 mi19.1°C 0.9°C warmer3.2°C 0.7°C colder1,133 mm
Month by month

Cemaes weather by month

Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (the Met Office’s HadUK-Grid).

MonthHighLowMeanRain
January8.4°C 47°F3.9°C 39°F6.3°C98 mm 3.8 in
February8.4°C 47°F3.7°C 39°F6.1°C76 mm 3.0 in
March9.6°C 49°F4.4°C 40°F7.0°C81 mm 3.2 in
April11.7°C 53°F5.9°C 43°F8.9°C64 mm 2.5 in
May14.4°C 58°F8.4°C 47°F11.4°C48 mm 1.9 in
June16.7°C 62°F10.7°C 51°F13.7°C65 mm 2.6 in
July18.2°C 65°F12.6°C 55°F15.4°C65 mm 2.5 in
August18.3°C 65°F12.8°C 55°F15.6°C62 mm 2.5 in
September16.9°C 62°F11.4°C 52°F14.1°C78 mm 3.1 in
October14.0°C 57°F9.2°C 49°F11.7°C105 mm 4.1 in
November11.3°C 52°F6.6°C 44°F8.9°C132 mm 5.2 in
December9.1°C 48°F4.5°C 40°F6.9°C108 mm 4.3 in
Year13.1°C7.8°C10.5°C981 mm
Sources

Where Cemaes’s numbers come from

Averages over 30 years, not a forecast.

  • Mean temperature, rain and day counts: HadUK-Grid 1991–2020 averages for the Met Office 2 km grid square nearest Cemaes’s centre (the town is smaller than one square).
  • Highs and lows: the Met Office publishes average daily maxima and minima on its 12 km grid; each is moved by the difference between the town’s 2 km mean temperature and the 12 km square’s, which carries the town’s own height and setting over.
  • Weather station and sunshine: Met Office historic station data for Valley, 12 miles away, months of 1991–2020 averaged.
  • Comparisons: every town and city of 2,500 or more across the UK, all four nations, read the same way.

Met Office HadUK-Grid · Met Office Climate Data Portal · Historic station data. Open Government Licence v3.0.

Questions about Cemaes’s climate

How warm does Cemaes get in summer?

August is the warmest month, with average highs of 18.3°C (65°F). About 1 days a year reach 25°C (77°F), fewer than 97% of UK towns.

How cold does Cemaes get in winter?

February nights average 3.7°C (39°F). The air drops below freezing on about 11 nights a year, and about 0 days a year stay below freezing all day.

How much rain does Cemaes get?

About 981 mm (39 in) a year, more than 77% of UK towns. November is the wettest month (132 mm) and May the driest (48 mm).

How sunny is it?

The nearest Met Office station with a sunshine record, Valley (Anglesey) (12 miles away), averages 1,575 hours of bright sunshine a year. Sunshine isn’t on the town grid, so this is the station’s figure.

Where do these figures come from?

The Met Office’s HadUK-Grid 1991–2020 averages, which turn thousands of weather stations into a map of the UK in 2 km squares; the page reads the squares inside Cemaes. They are 30-year averages, not a forecast.

Contains Met Office data © Crown copyright 2026, Open Government Licence v3.0. HadUK-Grid 1991–2020 averages via the Met Office Climate Data Portal; station averages from Met Office historic station data. Today’s forecast for Cemaes →

Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.