Kos is warmest in July, averaging 33° by day and 24° at night. The wettest month is December with 183 mm, and the year brings about 618 mm in total.
Month by month
| Month | High | Low | Rain | Sea | Daylight | Good for |
|---|---|---|---|---|---|---|
| January | 15° | 10° | 130 mm | 18° | 9.7 h | Mild |
| February | 16° | 11° | 73 mm | 17° | 10.6 h | Mild |
| March | 17° | 12° | 65 mm | 17° | 11.7 h | Sightseeing |
| April | 20° | 14° | 18 mm | 18° | 13.0 h | Sightseeing |
| May | 24° | 18° | 16 mm | 20° | 14.0 h | Sightseeing |
| June | 29° | 22° | 6 mm | 23° | 14.5 h | Beach weather |
| July | 33° | 24° | 0 mm | 25° | 14.3 h | Beach weather |
| August | 32° | 25° | 6 mm | 26° | 13.4 h | Beach weather |
| September | 30° | 22° | 18 mm | 25° | 12.2 h | Beach weather |
| October | 26° | 19° | 22 mm | 23° | 11.0 h | Beach weather |
| November | 21° | 16° | 81 mm | 21° | 10.0 h | Sightseeing |
| December | 17° | 12° | 183 mm | 20° | 9.5 h | Mild |
High and low are average daily maximum and minimum, rain is typical monthly total, sea is the average surface temperature, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER and NOAA MUR — averages, not promises.
When to go
Beach weather: June, July, August, September and October — highs around 30°, nights no colder than 19°, and at most 22 mm of rain in a month. The sea sits at 23–26° then.
Walking the city: March, April, May and November — highs of 17–24° and no more than 81 mm of rain a month.