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Live forecasts update automatically; written guidance last reviewed 13 June 2026 by the Insight Britain weather desk. Data from national met services via Open-Meteo.
Live data from Open-Meteo · updates automatically ·
The live forecast above shows Carmarthen’s weather hour by hour and day by day. Use the tabs to switch between a detailed hourly view and the longer outlook, and check the rain radar for incoming showers.
How should I read the live forecast for Carmarthen?
The widget displays temperature, wind speed and direction, humidity, and precipitation probability. The coloured bar indicates rain intensity: light blue for drizzle, darker shades for heavier rain. Wind arrows show direction and strength, with longer arrows meaning stronger gusts.
What is Carmarthen’s typical climate through the seasons?
Carmarthen has a mild maritime climate, heavily influenced by the nearby Bristol Channel and Atlantic weather systems. Winters (December to February) are cool and damp, with daytime highs rarely far above single figures and frequent rain. Frost is occasional but not severe. Spring (March to May) brings slowly rising temperatures and longer dry spells, though April showers are common. Summers (June to August) are pleasantly warm but not hot, with average highs in the upper teens to low twenties Celsius. Rain remains possible throughout. Autumn (September to November) sees increasing wind and rain as Atlantic lows return, with mild temperatures gradually falling.
How do local geography and the coast affect Carmarthen’s weather?
Carmarthen sits in the Tywi valley, sheltered by hills to the north and east. This valley can trap cloud and mist, especially on autumn and winter mornings. The nearby coast at Carmarthen Bay moderates temperatures, keeping winters slightly milder and summers cooler than inland areas. South-westerly winds bring the most rain, while the Preseli Hills to the north can block some weather systems, creating a slight rain shadow effect.
When is the best time to visit Carmarthen, and what should I pack?
Late spring (May) and early autumn (September) offer the best balance of mild weather and lower rainfall. For any visit, pack a waterproof jacket and layers, as conditions can change quickly. In summer, light clothing and sun cream are useful for brighter spells. In winter, a warm coat and sturdy shoes are essential for damp, chilly days.
Key facts about Carmarthen weather
What other local weather guides should I check?
Readers often compare Carmarthen with nearby towns. See the Llanelli weather guide for coastal conditions, the Tenby weather guide for the Pembrokeshire coast, and the Swansea weather guide for the wider Swansea Bay area. For a broader view, visit the UK weather hub or the full list of UK towns.
Frequently asked questions about Carmarthen weather
What will the weather be in Carmarthen tomorrow?
Check the live forecast above for the most accurate hourly breakdown. Generally, tomorrow’s weather in Carmarthen follows the same maritime pattern: a mix of cloud, some rain at times, and moderate south-westerly winds. Temperatures will be typical for the season.
What is the 10 to 14 day outlook for Carmarthen?
The 10 to 14 day outlook, shown in the live forecast above, gives a general trend rather than precise details. Expect alternating bands of rain and drier, brighter spells as Atlantic weather systems move through. Confidence decreases beyond day 7, so check the 10-day forecast regularly for updates.
Does it rain a lot in Carmarthen?
Yes, Carmarthen receives above-average rainfall for the UK, around 1,200 mm per year. Rain is fairly evenly distributed, though autumn and winter tend to be wetter. The town’s valley location can also lead to persistent drizzle and mist, especially in the cooler months.
Are there any weather warnings for Carmarthen?
Weather warnings for Carmarthen are issued by the Met Office and displayed in the live forecast above. For the latest alerts, including wind and rain warnings, visit the UK weather warnings page. Warnings are most common in autumn and winter during Atlantic storms.