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London · September · warmth

Warmest places to go from London in September

The warmest place you can reach from London in September within 15 hours is Sharm el-Sheikh at 33.7 °C, costing 909 kg CO₂e return. The lowest-carbon option is Calais at 4.5 kg — 202× less carbon for 16.5 °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.

CalaisSharm el-Sheikh
Where they are. Solid lines are rail or ferry, dashed are flights, from London. Pick one to compare.
Carbon against warmth, September, departing London. Journeys of up to 15 hours each way.15 destinations. Lowest carbon Calais at 4.5 kilograms and 17.2 °C; best for warmth Sharm el-Sheikh at 909 kilograms and 33.7 °C. Calais · 4.5 kgArles · 27.8 kgCannes · 260 kgSharm el-Sheikh · 909 kg

By rail or ferry By air

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

What the 15-hour limit costs: at this budget Cannes can only be reached by air — 260 kg CO₂e, in 4h 54m. Allow up to 24 hours and the train does the same journey for 30.5 kg in 16h 6m — 9× less carbon for 11h 12m more travelling.

September from London — 15 destinations on the frontier, 5 without flying.
DestinationHowCO₂e returnTempSun/dayRain/dayJourney
Calais, FranceRail4.5 kg17.2 °C8.8 h3.3 mm4h 6m
Bourges, FranceRail15.5 kg18.0 °C9.0 h2.8 mm9h 12m
Bordeaux, FranceRail21.9 kg18.9 °C9.8 h3.2 mm12h 12m
Avignon, FranceRail27.1 kg20.1 °C10.3 h3.1 mm14h 36m
Arles, FranceRail27.8 kg20.8 °C10.4 h2.6 mm14h 54m
Cannes, FranceAir260 kg21.7 °C10.3 h3.3 mm4h 54m
Bastia, FranceAir306 kg22.5 °C10.6 h1.9 mm5h 6m
Alzira, SpainAir346 kg23.3 °C10.1 h2.4 mm5h 18m
Ibiza Town, SpainAir354 kg24.2 °C10.8 h1.6 mm5h 24m
Bizerte, TunisiaAir445 kg25.4 °C10.8 h0.4 mm5h 54m
Kairouan, TunisiaAir488 kg27.0 °C10.7 h0.7 mm6h 6m
Tozeur, TunisiaAir520 kg29.4 °C10.3 h0.3 mm6h 18m
Assiut, EgyptAir881 kg31.6 °C11.7 h0.0 mm8h 30m
Sohag, EgyptAir901 kg32.3 °C11.7 h0.0 mm8h 36m
Sharm el-Sheikh, EgyptAir909 kg33.7 °C11.5 h0.0 mm8h 42m

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 Arles (27.8 kg, 20.8 °C) to Cannes (260 kg, 21.7 °C) buys 0.9 °C more warmth for an extra 232 kg — 258 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 London 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 London

September from elsewhere

Questions

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

Sharm el-Sheikh, Egypt, at 33.7 °C. Reaching it emits 909 kg CO₂e return, travelling 8h 42m each way by air.

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

Yes. Arles reaches 20.8 °C and is reachable by rail or ferry in 14h 54m, emitting 27.8 kg CO₂e return — though Sharm el-Sheikh is warmer still, if you fly.

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

909 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.