Month by month
| Month | Afternoon | Sea | Rain | Verdict |
|---|---|---|---|---|
| January | 12.9 °C | 16 °C | 8 days | Possible, with trade-offs |
| February | 14.5 °C | 15.1 °C | 6 days | Possible, with trade-offs |
| March | 16.5 °C | 15.3 °C | 7 days | Possible, with trade-offs |
| April | 21.1 °C | 16.5 °C | 4 days | Pleasant — a good time to go |
| May | 25.6 °C | 19.1 °C | 5 days | Ideal — one of the best times of year |
| June | 30.8 °C | 22.9 °C | 4 days | Ideal — one of the best times of year |
| July | 34.2 °C | 26 °C | 1 day | Ideal — one of the best times of year |
| August | 33.7 °C | 26.6 °C | 2 days | Ideal — one of the best times of year |
| September | 29.3 °C | 25.6 °C | 3 days | Ideal — one of the best times of year |
| October | 24 °C | 23.5 °C | 3 days | Pleasant — a good time to go |
| November | 19.3 °C | 21.1 °C | 6 days | Pleasant — a good time to go |
| December | 14.8 °C | 18.2 °C | 7 days | Possible, with trade-offs |
Before you go
Three things to check once you have picked your dates.
Entry
Greece is in the European Union. Entry rules depend on your nationality — check before booking.
Safety
No specific restrictions
Usual precautions apply.
Official advice updated 11 August 2026
Health
Recommended vaccinations, water quality, mosquitoes: advice depends on the country and the season. Some vaccines need time before departure.
Beau Fixe is not a safety or health authority. These notes summarise public advisories and link to their source; only the competent authorities are authoritative. Alert levels: Foreign, Commonwealth & Development Office (gov.uk), Open Government Licence v3.0.
FAQ
Can you swim in Piraeus in September?
The sea averages 25.6°C in September — yes, pleasant swimming.
How hot is Piraeus in September?
Expect 29.3°C in the afternoon and 20.1°C at night, averaged over the last 10 years.
Does it rain a lot in Piraeus in September?
Around 3 days with rain (≥ 1 mm) in the month — 12% of days.