Rome · September · sunshine

Sunniest places to go from Rome in September

The sunniest place you can reach from Rome in September within 15 hours is Heraklion at 11.6 h, costing 331 kg CO₂e return. The lowest-carbon option is Grosseto at 4.4 kg — 75× less carbon for 1.2 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.

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

By rail or ferry By air

Carbon against sunshine, September, departing Rome. Journeys of up to 15 hours each way.

September from Rome — 3 destinations on the frontier, 2 without flying.
Destination	How	CO₂e return	Temp	Sun/day	Rain/day	Journey
Grosseto, Italy	Rail	4.4 kg	21.7 °C	10.4 h	3.1 mm	4h 6m
Bari, Italy	Rail	11.0 kg	23.5 °C	10.9 h	1.2 mm	7h 6m
Heraklion, Greece	Air	331 kg	24.0 °C	11.6 h	1.0 mm	5h 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 Bari (11.0 kg, 10.9 h) to Heraklion (331 kg, 11.6 h) buys 0.7 hours more sunshine for an extra 320 kg — 457 kg of CO₂e per hour. That single step is the most expensive sunshine on the whole curve.

The pick of them

GrossetoItaly4.4 kg CO₂e return21.7 °C · 10.4 h sun · 4h 6m by railwarm but wet BariItaly11.0 kg CO₂e return23.5 °C · 10.9 h sun · 7h 6m by railwarm overall HeraklionGreece331 kg CO₂e return24.0 °C · 11.6 h sun · 5h 18m by airwarm, bright and dry

If you'd rather have heat than sunshine

September answers differently depending on what you're after. The warmest destinations from Rome 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 Heraklion

Places to stay in Heraklion, Greece, 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 Rome

September from elsewhere

Questions

Where is the sunniest place to go from Rome in September?

Heraklion, Greece, at 11.6 h. Reaching it emits 331 kg CO₂e return, travelling 5h 18m each way by air.

Can I get somewhere sunny from Rome in September without flying?

Yes. Bari reaches 10.9 h and is reachable by rail or ferry in 7h 6m, emitting 11.0 kg CO₂e return — though Heraklion is sunnier still, if you fly.

How much carbon does a return trip from Rome to Heraklion produce?

331 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.