Weather in Athens in September

How September compares

September is the 4th warmest month of the year in Athens and ranks 47th of 134 destinations we compare for September - see where else is hot in September. Within Greece it is 9th of 44 (Greece in September). Against London's average high of 18.6°C in September, Athens is 9.6°C warmer by day and 7.7°C warmer at night.

Daytime and night-time in September

The typical September day in Athens peaks at 28.2°C, but that is an average: the warmest 10% of days reach 32.3°C or more. About 83% of days top 25°C and 1 in 3 pass 30°C. Nights average 18.9°C; one night in ten drops to 16.0°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 38.6°C (2015-09-06) and the coldest night 11.9°C (2000-09-30).

Rain in September

Dry (3 rainy days or fewer): about 3 days with 1 mm or more, 17 mm in total. Year to year it varies a lot - the wettest September was 2018 with 116 mm, the driest 1994 with 0 mm. Humidity averages 60%.

Sea temperature in September

The sea averages 25.2°C - warm enough to swim (22°c+). Depending on the year it ranges from 24.5°C to 26.1°C. For the warmest sea here, come in August (26.3°C).

Sunshine and daylight

Around 9.7 hours of sunshine a day (estimated from cloud cover), 12.2 hours of daylight: the sun rises about 07:07 and sets about 19:34 local time in mid-September. Average cloud cover is 20%.

Is September a good time to visit Athens?

Yes - it is one of the better months: hot days, little rain and long sunny days. The best months for Athens on our scoring are June, September, May; months averaging 25°C or more: May, Jun, Jul, Aug, Sep.

Expect heat, not an autumn cool-down

September suits travellers who enjoy warmth, but it can still feel demanding if you spend much of the day walking. Temperatures reach 25°C on 83% of days, and 30°C on 31%, so cooler weather is not something to rely on. The hottest days can push beyond the usual daytime average, making shade and breaks important. Put longer walks in the morning, leave room for a slower midday spell, and carry water. Lightweight, breathable clothes are the sensible starting point, with comfortable footwear and a hat. If you dislike heat, the month is less straightforward: warm evenings are a benefit, but afternoons may still limit how active you want to be.

Mostly dry, with plenty of usable daylight

Rain is unlikely to dominate a September trip, with about 3 rainy days during the month. That favours flexible outdoor plans, though it does not guarantee a dry stay; keep an indoor alternative available rather than packing the schedule too tightly. Around 9.7 hours of sunshine within 12.2 hours of daylight gives you plenty of scope to spend time outside without doing everything at midday. Sun cream and sunglasses deserve space in your bag, while a compact waterproof is a sensible precaution rather than the main packing priority. Overall, the balance works well for a city break with outdoor meals and time to pause, provided you are comfortable with hot afternoons.