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Vienna · September · relief from the heat

Coolest places to go from Vienna in September

In September, the coolest well-known place within 15 hours of Vienna is Reykjavik, Iceland, 10.8 °C cooler than Vienna and 6.3 h sun a day, about 7h 18m each way by air. Without flying, it is La Chaux-de-Fonds, Switzerland, 4.2 °C cooler than Vienna, about 11h 54m each way by train, for about 34× less carbon (21.4 kg CO₂e return against 726 kg).

The 10 coolest places within 15 hours of Vienna

Ranked on relief from the heat in September alone, among well-known places (a Wikivoyage travel guide and at least 40,000 Wikipedia readers a year), one per area and at most three per country. The carbon is shown, not used to choose: the list further down is the other question, how much relief from the heat each extra kilogram buys.

  1. Reykjavik, Iceland10.8 °C cooler · 6.3 h sun a day · 3.5 mm rain a day · sea 10.8 °Cair ≈ 7h 18m · 726 kg CO₂e return
  2. Tromsø, Norway8.6 °C cooler · 4.9 h sun a day · 5.2 mm rain a dayair ≈ 6h 42m · 601 kg CO₂e return
  3. Östersund, Sweden7.6 °C cooler · 7.7 h sun a day · 2.6 mm rain a dayair ≈ 5h 42m · 420 kg CO₂e return
  4. Bodø, Norway7.4 °C cooler · 5.2 h sun a day · 6.6 mm rain a day · sea 13.0 °Cair ≈ 6h 18m · 534 kg CO₂e return
  5. Rovaniemi, Finland7.1 °C cooler · 6.0 h sun a day · 3.5 mm rain a dayair ≈ 6h 18m · 529 kg CO₂e return
  6. Trondheim, Norway6.5 °C cooler · 7.0 h sun a day · 5.8 mm rain a dayair ≈ 5h 48m · 436 kg CO₂e return
  7. Sundsvall, Sweden6.0 °C cooler · 8.4 h sun a day · 2.3 mm rain a day · sea 14.2 °Cair ≈ 5h 36m · 397 kg CO₂e return
  8. Luleå, Sweden6.0 °C cooler · 7.7 h sun a day · 2.4 mm rain a day · sea 14.3 °Cair ≈ 6h 6m · 493 kg CO₂e return
  9. Dundee, United Kingdom5.9 °C cooler · 7.7 h sun a day · 2.0 mm rain a day · sea 13.9 °Cair ≈ 5h 36m · 401 kg CO₂e return
  10. Glasgow, United Kingdom5.3 °C cooler · 7.2 h sun a day · 3.4 mm rain a dayair ≈ 5h 42m · 412 kg CO₂e return

Without flying

The coolest places the train reaches within 15 hours. La Chaux-de-Fonds is 4.2 °C cooler for 21.4 kg — about 34× less carbon than flying to Reykjavik.

  1. La Chaux-de-Fonds, Switzerland4.2 °C cooler · 9.2 h sun a day · 3.5 mm rain a dayrail ≈ 11h 54m · 21.4 kg CO₂e return
  2. Zakopane, Poland3.8 °C cooler · 8.8 h sun a day · 3.9 mm rain a dayrail ≈ 6h 12m · 8.5 kg CO₂e return
  3. Memmingen, Germany3.3 °C cooler · 9.6 h sun a day · 3.5 mm rain a dayrail ≈ 7h 36m · 13.6 kg CO₂e return
  4. Bern, Switzerland2.9 °C cooler · 9.6 h sun a day · 3.6 mm rain a dayrail ≈ 11h 18m · 20.2 kg CO₂e return
  5. Munich, Germany2.6 °C cooler · 9.1 h sun a day · 4.1 mm rain a dayrail ≈ 5h 30m · 10.5 kg CO₂e return
  6. Augsburg, Germany2.3 °C cooler · 9.5 h sun a day · 3.2 mm rain a dayrail ≈ 6h 54m · 12.0 kg CO₂e return

≈ is the model's estimate (air times include getting to and through the airport); ✓ is a rail journey checked against a real timetable, with the date it was checked. Temperatures are historical daily means for 2023–2024, averaged across day and night, so afternoons run warmer.

The low-carbon trade-off

The coolest place you can reach from Vienna in September within 15 hours is Reykjavik, 10.8 °C cooler, costing 726 kg CO₂e return. The lowest-carbon option is Zdar at 4.5 kg — 161× less carbon, for 8.1 degrees less relief from the heat.

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

ZdarReykjavik
Where they are. Solid lines are rail or ferry, dashed are flights, from Vienna. Pick one to compare.
Carbon against relief from the heat, September, departing Vienna. Journeys of up to 15 hours each way.8 destinations. Lowest carbon Zdar at 4.5 kilograms and 2.7 °C cooler; best for relief from the heat Reykjavik at 726 kilograms and 10.8 °C cooler. Zdar · 4.5 kgZakopane · 8.5 kgOslo · 340 kgReykjavik · 726 kg

By rail or ferry By air

Carbon against relief from the heat, September, departing Vienna. Journeys of up to 15 hours each way.

What the 15-hour limit costs: at this budget Oslo can only be reached by air — 340 kg CO₂e, in 5h 18m. Allow up to 24 hours and the train does the same journey for 39.9 kg in 21h 36m — 9× less carbon for 16h 18m more travelling.

September from Vienna — 8 destinations on the frontier, 2 without flying.
DestinationHowCO₂e returnTempSun/dayRain/dayJourney
Zdar, CzechiaRail4.5 kg15.6 °C9.3 h3.7 mm4h 18m
Zakopane, PolandRail8.5 kg14.5 °C8.8 h3.9 mm6h 12m
Oslo, NorwayAir340 kg13.3 °C7.3 h3.4 mm5h 18m
Hamar, NorwayAir362 kg12.6 °C7.3 h3.4 mm5h 24m
Lillehammer, NorwayAir373 kg12.0 °C7.0 h4.6 mm5h 30m
Östersund, SwedenAir420 kg10.7 °C7.7 h2.6 mm5h 42m
Tromsø, NorwayAir601 kg9.7 °C4.9 h5.2 mm6h 42m
Reykjavik, IcelandAir726 kg7.5 °C6.3 h3.5 mm7h 18m

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 Zakopane (8.5 kg, 3.8 °C cooler) to Oslo (340 kg, 5.0 °C cooler) buys 1.2 °C more relief from the heat for an extra 331 kg — 276 kg of CO₂e per degree. That single step is the most expensive relief from the heat on the whole curve.

The pick of them

Zdar, CzechiaZdarCzechia4.5 kg CO₂e return15.6 °C · 9.3 h sun · 4h 18m by railwarm but wetZakopane, PolandZakopanePoland8.5 kg CO₂e return14.5 °C · 8.8 h sun · 6h 12m by railmild and brightReykjavik, IcelandReykjavikIceland726 kg CO₂e return7.5 °C · 6.3 h sun · 7h 18m by aircool

The same month, asked differently

September answers differently depending on what you are after, and the lists genuinely diverge: the brightest places are not the hottest, and in summer the useful question stops being where is warm at all.

Where to stay in Reykjavik

Places to stay in Reykjavik, Iceland, on a live map. Prices and availability come from Stay22 and its booking partners.

Search places to stay in Reykjavik →Opens the booking search in a new tab. Same partners as the map below.

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 Vienna

September from elsewhere

Photo credits

Questions

Where is the coolest place to go from Vienna in September?

Reykjavik, Iceland, at 10.8 °C cooler. Reaching it emits 726 kg CO₂e return, travelling 7h 18m each way by air (modelled).

Can I get somewhere cool from Vienna in September without flying?

Yes. Zakopane reaches 3.8 °C cooler and is reachable by rail or ferry in 6h 12m (modelled), emitting 8.5 kg CO₂e return — though Reykjavik is cooler still, if you fly.

How much carbon does a return trip from Vienna to Reykjavik produce?

726 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.