Carmarthen Temperature by Month
The average annual maximum temperature in Carmarthen, Dyfed, United Kingdom is 14°C (57°F), with daytime highs ranging from 9°C (48°F) in February to 20°C (68°F) in July. This page covers monthly averages, day-night differences, and how Carmarthen compares to cities worldwide.
Carmarthen Monthly Temperatures
In Carmarthen, seasonal changes bring about a moderate variation in temperatures. Nighttime lows range from 13°C (55°F) in July to 4°C (39°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Carmarthen by month:
The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest.
The chart below shows the average temperature throughout the year:
Temperature: Carmarthen vs the United Kingdom
The map below shows the annual temperature across the United Kingdom. You can also select individual months if you want to compare a specific time of year.
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Carmarthen vs World: Temperature Compared
Carmarthen's average annual maximum temperature is 14°C (57°F). To put that in context, here's how it compares to a few well-known destinations:
Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.
On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.
Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round — large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.
For more on Carmarthen's weather — including monthly rainfall, sunshine hours, and humidity — visit our Carmarthen climate page.
