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Cardiff · September · warmth

Warmest places to go from Cardiff in September

The warmest place you can reach from Cardiff in September within 15 hours is Sharm el-Sheikh at 33.7 °C, costing 953 kg CO₂e return. The lowest-carbon option is Portsmouth at 13.2 kg — 72× less carbon for 17.1 °C less.

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

PortsmouthSharm el-Sheikh
Where they are. Solid lines are rail or ferry, dashed are flights, from Cardiff. Pick one to compare.
Carbon against warmth, September, departing Cardiff. Journeys of up to 15 hours each way.17 destinations. Lowest carbon Portsmouth at 13.2 kilograms and 16.6 °C; best for warmth Sharm el-Sheikh at 953 kilograms and 33.7 °C. Portsmouth · 13.2 kgTozeur · 542 kgAl Fayyum · 874 kgSharm el-Sheikh · 953 kg

By rail or ferry By air

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

What the 15-hour limit costs: at this budget Cannes can only be reached by air — 293 kg CO₂e, in 5h 6m. Allow up to 24 hours and the train does the same journey for 47.5 kg in 19h — 6× less carbon for 13h 54m more travelling.

September from Cardiff — 17 destinations on the frontier, 4 without flying.
DestinationHowCO₂e returnTempSun/dayRain/dayJourney
Portsmouth, United KingdomRail13.2 kg16.6 °C8.6 h3.5 mm4h 12m
Dunkirk, FranceRail22.4 kg17.3 °C8.8 h3.0 mm7h 24m
Angers, FranceRail30.3 kg17.8 °C9.0 h2.3 mm11h
La Rochelle, FranceRail34.7 kg18.7 °C10.0 h3.5 mm13h 6m
Nîmes, FranceAir256 kg20.3 °C10.4 h2.3 mm4h 54m
Perpignan, FranceAir271 kg21.3 °C10.1 h1.1 mm4h 54m
Cannes, FranceAir293 kg21.7 °C10.3 h3.3 mm5h 6m
Valencia, SpainAir340 kg22.9 °C10.6 h3.5 mm5h 18m
Alzira, SpainAir349 kg23.3 °C10.1 h2.4 mm5h 18m
Ibiza Town, SpainAir363 kg24.2 °C10.8 h1.6 mm5h 24m
Bizerte, TunisiaAir474 kg25.4 °C10.8 h0.4 mm6h
Kairouan, TunisiaAir516 kg27.0 °C10.7 h0.7 mm6h 12m
Tozeur, TunisiaAir542 kg29.4 °C10.3 h0.3 mm6h 24m
Al Fayyum, EgyptAir874 kg30.3 °C11.7 h0.0 mm8h 30m
Assiut, EgyptAir923 kg31.6 °C11.7 h0.0 mm8h 48m
Sohag, EgyptAir943 kg32.3 °C11.7 h0.0 mm8h 54m
Sharm el-Sheikh, EgyptAir953 kg33.7 °C11.5 h0.0 mm8h 54m

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 Tozeur (542 kg, 29.4 °C) to Al Fayyum (874 kg, 30.3 °C) buys 0.9 °C more warmth for an extra 332 kg — 369 kg of CO₂e per degree. That single step is the most expensive warmth on the whole curve.

The pick of them

If you'd rather have sunshine than heat

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

Where to stay in Sharm el-Sheikh

Places to stay in Sharm el-Sheikh, 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

September from elsewhere

Questions

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

Sharm el-Sheikh, Egypt, at 33.7 °C. Reaching it emits 953 kg CO₂e return, travelling 8h 54m each way by air.

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

Yes. La Rochelle reaches 18.7 °C and is reachable by rail or ferry in 13h 6m, emitting 34.7 kg CO₂e return — though Sharm el-Sheikh is warmer still, if you fly.

How much carbon does a return trip from Cardiff to Sharm el-Sheikh produce?

953 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.