Best time to visit Kos
Re-score for me — drag the dial — every chart recolours live for your heat & sea limits 27°C · sea 29°C
Default 27 °C is the upper edge of the Holiday Climate Index "ideal comfort" band (Scott, Rutty, Amelung & Tang, 2016). Above this, most warm-tourism travellers report measurable discomfort.
Default 29 °C is the Beach Climate Index "bathtub" line (Morgan et al.) — where the sea stops being refreshing and starts feeling like a warm bath.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
Greyed factors are scored normally — extreme heat overrides them, so a clear sky or low rain can't lift the period.
How is this scored? HCI / Steadman / CCI gate — full methodology and citations below.
Compare with another destination
Add as many as you like — stacked below the main strips above. Each row is just the recent-window score strip and (for beach destinations) sea-temperature strip.
Tours in Kos
7 top-rated tours via Viator. Booking links earn this site a commission at no cost to you. Map locations are approximate (centred on Kos).
- 1
Full-Day Tour to Nisyros The Volcano Island - 2
Kos: Small Group Full-Day Sailing with Meal, Drinks, & Swim - 3
Private Transfer from Kos Airport to Kos Hotels - 4
3 Island Luxury Cruise with 4 Swimming Stops with Captain Morgan - 5
Kos Old Town Walking Tour with Local Guide - 6
Roundtrip Minivan Transfer to Therma Natural Spa Beach - 7
Kos Local Tasting - Wine, Oil & Honey
Last refreshed 2026-06-09.
Similar climatesNaxos97% · Rhodes96% · Paros95%
Other destinations with the most-alike year-round climate to Kos (apparent temperature, rain hours, sunshine — matched within the same trip-profile). The ±N chip compares each match's typical score for the current month against Kos's. Based on the 2020-2024 climatology, not this year's actual weather.
Month-by-month
| Month | Temp °C | Feels °C | Rain days | Rain h | Rain h/day | Humidity | Wind km/h | Sun h | UV | Interest | Score |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jan | 11–15 | 11 | 13 | 145 | 11.2 | 64% | 27 | 183 | 2 | Quiet | 6 |
| Feb | 11–15 | 12 | 7 | 85 | 12.1 | 63% | 26 | 197 | 3 | Quiet | 8 |
| Mar | 11–16 | 13 | 9 | 90 | 10.0 | 61% | 26 | 236 | 4 | Quiet | 8 |
| Apr | 14–20 | 17 | 5 | 47 | 9.4 | 61% | 24 | 255 | 6 | Quiet | 9 |
| May | 17–24 | 23 | 3 | 27 | 9.0 | 57% | 21 | 301 | 7 | Moderate | 10 |
| Jun | 22–28 | 28 | 1 | 19 | 19.0 | 54% | 23 | 310 | 9 | Moderate | 10 |
| Jul | 25–31 | 31 | 0 | 0 | — | 47% | 27 | 321 | 10 | Busy | 7 |
| Aug | 25–31 | 32 | 1 | 5 | 5.0 | 51% | 23 | 299 | 9 | Peak | 7 |
| Sep | 23–28 | 28 | 1 | 11 | 11.0 | 52% | 23 | 267 | 7 | Moderate | 10 |
| Oct | 19–24 | 24 | 2 | 32 | 16.0 | 54% | 20 | 236 | 5 | Quiet | 10 |
| Nov | 16–20 | 19 | 9 | 99 | 11.0 | 60% | 22 | 200 | 3 | Quiet | 8 |
| Dec | 14–17 | 15 | 14 | 177 | 12.6 | 67% | 24 | 185 | 2 | Quiet | 6 |
UV Index in Kos by Month
UV index in Kos peaks at 10 (very high) in July, dropping to 2 (low) in December. June, July, August reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.
Best months in detail
October
10/1019–24°C · 2 rain days (32h) · 236 sun hours · 54% humidity · Quiet crowd · UV 5 (moderate)
May
10/1017–24°C (feels 23°C) · 3 rain days (27h) · 301 sun hours · 57% humidity · Moderate crowd · UV 7 (high) · sunniest 1 in 10 days reach 9 (very high)
June
10/1022–28°C · 1 rain days (19h) · 310 sun hours · 54% humidity · Moderate crowd · UV 9 (very high)
Every month
Show the other 9 months in detail
January
6/1011–15°C (feels 11°C) · 13 rain days (145h) · 183 sun hours · 64% humidity · Quiet crowd · UV 2 (low)
February
8/1011–15°C (feels 12°C) · 7 rain days (85h) · 197 sun hours · 63% humidity · Quiet crowd · UV 3 (moderate)
March
8/1011–16°C (feels 13°C) · 9 rain days (90h) · 236 sun hours · 61% humidity · Quiet crowd · UV 4 (moderate)
April
9/1014–20°C (feels 17°C) · 5 rain days (47h) · 255 sun hours · 61% humidity · Quiet crowd · UV 6 (high)
July
7/1025–31°C · 0 rain days (0h) · 321 sun hours · 47% humidity · Busy crowd · UV 10 (very high)
August
7/1025–31°C · 1 rain days (5h) · 299 sun hours · 51% humidity · Peak crowd · UV 9 (very high)
September
10/1023–28°C · 1 rain days (11h) · 267 sun hours · 52% humidity · Moderate crowd · UV 7 (high)
November
8/1016–20°C (feels 19°C) · 9 rain days (99h) · 200 sun hours · 60% humidity · Quiet crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)
December
6/1014–17°C (feels 15°C) · 14 rain days (177h) · 185 sun hours · 67% humidity · Quiet crowd · UV 2 (low)
Frequently asked questions about visiting Kos
When is the best time to visit Kos?
October is the highest-scoring month (10/10 on the Holiday Climate Index). Typical conditions: 19–24°C (2 rainy days). The top three months by score are October, May, June.
What is the worst time to visit Kos?
December is the lowest-scoring month (6/10). Typical conditions: 14–17°C (14 rainy days).
Is Kos too hot in summer?
2 months (July, August) trip the heat deal-breaker in our scoring: apparent temperature crosses the comfort cap, so even with clear skies and low rain the score is held down. Plan around it if heat tolerance is low.
When are crowds lowest in Kos?
Search-interest seasonality (Google Trends 2021-2025) is lowest in February and peaks in August. Interest tracks both in-trip visitors and lead-time planners, so treat it as a "destination is on people's minds" signal rather than literal arrivals.
Which months in Kos have good weather but fewer tourists?
May (climate 10/10, crowd index 42) and October (climate 10/10, crowd index 12) — shoulder months with above-average climate and below-median search-interest. Often the best value-for-weather trade.
What is the UV index in Kos by month?
UV peaks at 10 (very high) in July and is lowest in December at 2 (low). Monthly peak values: Jan 2, Feb 3, Mar 4, Apr 6, May 7, Jun 9, Jul 10, Aug 9, Sep 7, Oct 5, Nov 3, Dec 2. June, July, August reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.
What is the UV index in Kos in July?
July is the peak UV month in Kos, with a daily-peak UV index of 10 (very high). At this level, sunburn can occur in under 20 minutes on unprotected fair skin. Apply SPF 50+, wear protective clothing and a hat, and avoid direct midday sun (11:00–17:00).
How high can UV get in Kos on the sunniest days?
Most days look like the monthly average, but on the sunniest ~1 in 10 days UV climbs higher than the mean suggests. May is the worst case: typical days average UV 7 (high), but the top 10% of days reach UV 9 (very high) — and even higher. Months where the sunniest days routinely exceed the typical reading: May, November. Plan sun protection for the worst case, not the average.
Is air quality in Kos bad for travelers?
PM2.5 (fine-particle pollution) exceeds the WHO sensitive-group guideline (15 µg/m³) in 4 months: March, June, July, August. The worst month is August with a typical-day mean of 11 µg/m³ (moderate); on the worst 10% of days PM2.5 reaches 15 µg/m³ (unhealthy for sensitive) and higher. People with asthma, heart conditions, or sensitive children may want to avoid these months or limit outdoor activity. Source: CAMS via Open-Meteo.