Weather in Kos in September 2025
Average weather
Average temperature in Kos in September
Going from a maximum of +29°C during the day to a minimum of +22°C during the night, the temperature in September averages around +27°C.
The average maximum temperature goes down 57% by the end of the month, compared with the beginning of the month, from +28°C to +24°C.
Is Kos warm or cold in September?
Kos is typically warm in September.
Maximum temperatures go down compared to the previous month from +28°C to +25°C. The minimum temperature also goes down from +25°C to +23°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
September is one of the warmest months in Kos, here is the comparison with other months:
Water temperature in Kos in September
Water in Kos in September is Warm. It varies from +24°C to +27°C, with an average of +26°C. Note that the air temperature is lower than the water temperature, averaging around +25°C.
The water temperature in September is one of the warmest of the entire year:
Can you swim in Kos in September?
Climate in Kos in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +28°C | +25°C | +22°C | ||||
| Min. temperature | ||||||
| +22°C | +17°C | +11°C | ||||
| Max. temperature | ||||||
| +38°C | +36°C | +36°C | ||||
| Rainfall | ||||||
| 0 mm | 9 mm | 42 mm | ||||
| Wind | ||||||
| 6 m/s | 6 m/s | 5 m/s | ||||
| Avg. water temperature | ||||||
| +26°C | +26°C | +23°C | ||||
| Humidity | ||||||
| 79% | 76% | 75% | ||||
| Air pressure | ||||||
| 1007 HPa | 1011 HPa | 1014 HPa | ||||
| Sunny days | ||||||
| 31 | 26 | 18 | ||||
| Cloudy days | ||||||
| 0 | 2 | 7 | ||||
| Rainy days | ||||||
| 0 | 2 | 7 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as great as in August. It’s getting colder in September. From +28°C in the day, the average maximum temperature lowers to +25°C. Prepare for more rain. Average rainfall goes from 0 mm to 9 mm. It feels drier, as humidity decreases from 79% to 76%. The average wind speed doesn’t change much during September, staying around 6 m/s. The days becoming less sunny, going from 31 sunny days in August to 26 in September.
Next month (October) brings a further decline in the weather.
Wind
The average wind speed is 6 m/s getting up to 9 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Kos is gradually increasing during September, going from 7 m/s to 7 m/s over the course of the month.
Rain
How was the weather last September in Kos?
Climate Change over Years
The climate in Kos in September has not changed much over the last 43 years.
The average temperature was the lowest in 1992 (+19°C) and the highest in 2018 (+24°C). The driest year was 1992 with only 335 mm of rainfall, and the wettest year was 2019 with 1062 mm.
FAQ
Is September a good time to visit Kos?
Can you sunbathe in Kos in September?
Can you swim in Kos in September?
Is Kos rainy in September?
Is it sunny in Kos in September?
Other cities in Greece
Monthly weather in Kos
Source of the data
For this page, we’ve looked at the typical weather in Kos, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.