Cardiff · August · warmth

Warmest places to go from Cardiff in August

The warmest place you can reach from Cardiff in August within 15 hours is Kom Ombo at 36.8 °C, costing 1,004 kg CO₂e return. The lowest-carbon option is Portsmouth at 13.2 kg — 76× less carbon for 19.2 °C less.

Every destination here is on the efficiency frontier: nowhere else in Europe is both warmer in August and lower in carbon. Anything a better option beats outright has been left out.

Where they are. Solid lines are rail or ferry, dashed are flights, from Cardiff. Pick one to compare.

By rail or ferry By air

Carbon against warmth, August, departing Cardiff. Journeys of up to 15 hours each way.

What the 15-hour limit costs: at this budget Aix-les-Bains can only be reached by air — 233 kg CO₂e, in 4h 42m. Allow up to 24 hours and the train does the same journey for 40.1 kg in 15h 36m — 6× less carbon for 10h 54m more travelling.

August from Cardiff — 19 destinations on the frontier, 7 without flying.
Destination	How	CO₂e return	Temp	Sun/day	Rain/day	Journey
Portsmouth, United Kingdom	Rail	13.2 kg	17.6 °C	10.4 h	2.3 mm	4h 12m
Dunkirk, France	Rail	22.4 kg	18.5 °C	11.3 h	2.5 mm	7h 24m
Valenciennes, France	Rail	25.4 kg	19.2 °C	10.6 h	2.9 mm	8h 48m
Paris, France	Rail	27.1 kg	19.9 °C	10.3 h	4.1 mm	9h 36m
Mainz, Germany	Rail	35.1 kg	20.9 °C	10.6 h	2.2 mm	13h 18m
Chalon-sur-Saône, France	Rail	35.8 kg	21.9 °C	11.8 h	1.5 mm	13h 36m
Lyon, France	Rail	38.7 kg	23.3 °C	12.0 h	1.3 mm	15h
Aix-les-Bains, France	Air	233 kg	23.6 °C	11.5 h	1.7 mm	4h 42m
Montélimar, France	Air	244 kg	25.2 °C	12.6 h	1.2 mm	4h 48m
Perpignan, France	Air	271 kg	25.9 °C	12.2 h	0.6 mm	4h 54m
Zaragoza, Spain	Air	278 kg	27.2 °C	12.7 h	0.7 mm	5h
Madrid, Spain	Air	310 kg	28.2 °C	12.7 h	0.3 mm	5h 6m
Aranjuez, Spain	Air	320 kg	28.9 °C	12.8 h	0.4 mm	5h 12m
Andujar, Spain	Air	376 kg	31.1 °C	12.7 h	0.1 mm	5h 30m
Zawyat ech Cheikh, Morocco	Air	530 kg	31.8 °C	12.2 h	0.0 mm	6h 18m
Tozeur, Tunisia	Air	542 kg	33.1 °C	12.4 h	0.0 mm	6h 24m
Arfoud, Morocco	Air	561 kg	34.3 °C	12.1 h	0.0 mm	6h 30m
Zagora, Morocco	Air	594 kg	35.9 °C	12.1 h	0.0 mm	6h 36m
Kom Ombo, Egypt	Air	1,004 kg	36.8 °C	11.9 h	0.0 mm	9h 12m

Warm is not the same as pleasant, which is why sunshine and rainfall are shown alongside temperature. All three are ERA5 monthly means for 2023–2024.

Where the curve breaks

The frontier is gentle until it isn't. Going from Lyon (38.7 kg, 23.3 °C) to Aix-les-Bains (233 kg, 23.6 °C) buys 0.3 °C more warmth for an extra 194 kg — 648 kg of CO₂e per degree. That single step is the most expensive warmth on the whole curve.

The pick of them

PortsmouthUnited Kingdom13.2 kg CO₂e return17.6 °C · 10.4 h sun · 4h 12m by railwarm overall LyonFrance38.7 kg CO₂e return23.3 °C · 12.0 h sun · 15h by railwarm overall Kom OmboEgypt1,004 kg CO₂e return36.8 °C · 11.9 h sun · 9h 12m by airwarm, bright and dry

If you'd rather have sunshine than heat

August answers differently depending on what you're after. The sunniest destinations from Cardiff in August are a different list — the brightest places are not always the hottest, and in winter the difference is large.

Where to stay in Kom Ombo

Places to stay in Kom Ombo, Egypt, on a live map. Prices and availability come from Stay22 and its booking partners.

Affiliate disclosure. A booking made through this map may earn 0xCarbon a commission, at no extra cost to you. It changes nothing above it: the emissions figures come from UK Government conversion factors and are computed before anyone is paid anything.See the method.

Other months from Cardiff

August from elsewhere

Questions

Where is the warmest place to go from Cardiff in August?

Kom Ombo, Egypt, at 36.8 °C. Reaching it emits 1,004 kg CO₂e return, travelling 9h 12m each way by air.

Can I get somewhere warm from Cardiff in August without flying?

Yes. Lyon reaches 23.3 °C and is reachable by rail or ferry in 15h, emitting 38.7 kg CO₂e return — though Kom Ombo is warmer still, if you fly.

How much carbon does a return trip from Cardiff to Kom Ombo produce?

1,004 kg CO₂e for one person, return, by air. That uses the UK Government's 2026 conversion factors, including radiative forcing for flights.

Carbon uses UK Government (DESNZ/DEFRA) 2026 conversion factors applied to great-circle distance, with radiative forcing included for flights. Rail journey times are modelled estimates, not timetabled services. Full method · download the data.