Sunniest places to go from London in September
The sunniest place you can reach from London in September within 15 hours is Izmir at 11.6 h, costing 646 kg CO₂e return. The lowest-carbon option is Calais at 4.5 kg — 144× less carbon for 2.8 h less.
Every destination here is on the efficiency frontier: nowhere else in Europe is both sunnier in September and lower in carbon. Anything a better option beats outright has been left out.
By rail or ferry By air
What the 15-hour limit costs: at this budget Tomelloso can only be reached by air — 350 kg CO₂e, in 5h 24m. Allow up to 24 hours and the train does the same journey for 41.1 kg in 21h — 9× less carbon for 15h 36m more travelling.
| Destination | How | CO₂e return | Temp | Sun/day | Rain/day | Journey |
|---|---|---|---|---|---|---|
| Calais, France | Rail | 4.5 kg | 17.2 °C | 8.8 h | 3.3 mm | 4h 6m |
| Goes, The Netherlands | Rail | 8.2 kg | 17.5 °C | 9.3 h | 3.1 mm | 5h 48m |
| Düsseldorf, Germany | Rail | 14.2 kg | 17.5 °C | 9.9 h | 2.7 mm | 8h 36m |
| Avignon, France | Rail | 27.1 kg | 20.1 °C | 10.3 h | 3.1 mm | 14h 36m |
| Tomelloso, Spain | Air | 350 kg | 21.3 °C | 11.1 h | 1.4 mm | 5h 24m |
| Izmir, Turkey | Air | 646 kg | 24.9 °C | 11.6 h | 1.0 mm | 6h 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 Tomelloso (350 kg, 11.1 h) to Izmir (646 kg, 11.6 h) buys 0.5 hours more sunshine for an extra 296 kg — 592 kg of CO₂e per hour. That single step is the most expensive sunshine on the whole curve.
The pick of them
If you'd rather have heat than sunshine
September answers differently depending on what you're after. The warmest destinations from London in September are a different list — hours of sunshine and degrees of warmth come apart, especially early and late in the year.
Where to stay in Izmir
Places to stay in Izmir, Turkey, 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
- Amsterdam
- Barcelona
- Berlin
- Birmingham
- Bristol
- Brussels
- Cardiff
- Copenhagen
- Dublin
- Edinburgh
- Frankfurt
- Glasgow
- Leeds
- Lisbon
- Liverpool
- London
- Madrid
- Manchester
- Milan
- Munich
- Newcastle
- Nottingham
- Oslo
- Paris
- Prague
- Rome
- Sheffield
- Southampton
- Stockholm
- Vienna
- Warsaw
- Zurich
Questions
Where is the sunniest place to go from London in September?
Izmir, Turkey, at 11.6 h. Reaching it emits 646 kg CO₂e return, travelling 6h 54m each way by air.
Can I get somewhere sunny from London in September without flying?
Yes. Avignon reaches 10.3 h and is reachable by rail or ferry in 14h 36m, emitting 27.1 kg CO₂e return — though Izmir is sunnier still, if you fly.
How much carbon does a return trip from London to Izmir produce?
646 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.