January in Kos Island — off-season conditions
Hardest · 1.5/10January averages 13°C (56°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
At 145 mm this is a genuinely wet month: about 2 days with 6+ hours of sunshine in total, and outdoor plans need an indoor fallback.
It scores 1.5/10 here, 11th of 12 months, against 10/10 in the destination's best month.
Figure on low-season pricing, with crowds are light for this destination.
Pack layers you can shed by midday plus one warm layer for the evening, a proper rain shell rather than an umbrella.
Flexible dates? June scores 8.5 points higher here — enough to change the trip.
February in Kos Island — the hardest end of the year
Hardest · 3.7/10February averages 13°C (55°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
Rainfall runs 70 mm, so plan one flexible day in three; you still get about 9 days with 6+ hours of sunshine and 10.6 hours of daylight.
It scores 3.7/10 here, 10th of 12 months, against 10/10 in the destination's best month.
Figure on low-season pricing, with crowds are light for this destination.
Pack layers you can shed by midday plus one warm layer for the evening, a packable rain layer.
Flexible dates? June scores 6.3 points higher here — enough to change the trip.
March in Kos Island: mixed conditions, plan around the weather
Trade-offs · 5.2/10Temperatures hover around 14°C (57°F) — the kind of month where neither heat nor cold forces the schedule.
Budget for roughly 66 mm of rain this month — a flexible day or two helps — with about 19 days with 6+ hours of sunshine and 11.7 hours of daylight to work around it.
That is 5.2/10 on the same scale — 8th of 12 months, versus 10/10 for the best month here.
Expect mid-season pricing, and crowds are moderate.
Pack layers you can shed by midday plus one warm layer for the evening, a packable rain layer.
If your dates are flexible, June is materially better in Kos Island — 4.8 points higher on the same scale.
April in Kos Island: strong conditions, 7th of 12
Good · 7.5/10April averages 18°C (64°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
Expect 19 mm of rain — occasional showers rather than washed-out days — alongside about 28 days with 6+ hours of sunshine and 13 daylight hours.
It scores 7.5/10 here, 7th of 12 months, against 10/10 in the destination's best month.
Plan for mid-season pricing, with crowds are moderate.
Pack layers you can shed by midday plus one warm layer for the evening.
Flexible dates? June scores 2.5 points higher here — enough to change the trip.
May in Kos Island — one of the year's strongest windows (5th)
Best window · 8.9/10With 21°C (69°F) on average, May delivers classic beach weather: plenty of time in the water, with beach and boat plans rarely disrupted by cold.
With around 24 mm of rain, any showers tend to pass through rather than settle in; about 31 days with 6+ hours of sunshine and 14 hours of daylight fill the rest.
On our climate-comfort scale this is one of the strongest months of the year for Kos Island at 8.9/10 (5th of 12), just behind June at 10/10.
Budget for mid-season pricing, and crowds are moderate.
Pack light clothing, swimwear and real sun protection.
June in Kos Island tops the year's climate scores
Best window · 10/10June averages 26°C (79°F) — warm enough for beach and boat plans, still short of the heat that pushes sightseeing into early morning.
Rain is a non-issue at 9 mm for the month, with about 30 days with 6+ hours of sunshine and 14.5 hours of daylight to work with.
On our climate-comfort scale this is the top-ranked month of the year for Kos Island at 10/10 — the reference point every other month on this page is measured against.
Plan for peak pricing, with crowds are moderate. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack light clothing, swimwear and real sun protection.
July is one of the strongest months in Kos Island (2nd)
Best window · 10/10July averages 29°C (85°F), so the practical pattern is early mornings, a long midday break, and evenings back outside.
Rain is a non-issue at 2 mm for the month, with about 31 days with 6+ hours of sunshine and 14.3 hours of daylight to work with.
A 10/10 puts this among the year's best months in Kos Island (2nd of 12); only June scores higher, at 10/10.
Figure on peak pricing, with this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary.
August is one of the strongest months in Kos Island (3rd)
Best window · 10/10Days in August average 28°C (83°F) — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
At just 6 mm for the month, rain will not shape your plans; you get about 31 days with 6+ hours of sunshine and 13.4 hours of daylight.
On our climate-comfort scale this is one of the strongest months of the year for Kos Island at 10/10 (3rd of 12), just behind June at 10/10.
Budget for peak pricing, and this is one of the busiest months here. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary.
September ranks 4th of 12 for Kos Island — one of the best windows
Best window · 10/10Days in September average 26°C (79°F) — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
With around 27 mm of rain, any showers tend to pass through rather than settle in; about 26 days with 6+ hours of sunshine and 12.2 hours of daylight fill the rest.
On our climate-comfort scale this is one of the strongest months of the year for Kos Island at 10/10 (4th of 12), just behind June at 10/10.
Expect peak pricing, and crowds are moderate.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary.
October in Kos Island — one of the year's strongest windows (6th)
Best window · 8.8/10October averages 22°C (72°F) — warm enough for beach and boat plans, still short of the heat that pushes sightseeing into early morning.
Rain is a non-issue at 4 mm for the month, with about 17 days with 6+ hours of sunshine and 11 hours of daylight to work with.
A 8.8/10 puts this among the year's best months in Kos Island (6th of 12); only June scores higher, at 10/10.
Plan for mid-season pricing, with crowds are moderate.
Pack light clothing, swimwear and real sun protection.
November in Kos Island — off-season conditions
Hardest · 4/10November averages 19°C (65°F), the range most people find easiest for walking a city all day without either overheating or losing daylight to weather.
At 114 mm this is a genuinely wet month: about 5 days with 6+ hours of sunshine in total, and outdoor plans need an indoor fallback.
It scores 4/10 here, 9th of 12 months, against 10/10 in the destination's best month.
Figure on low-season pricing, with crowds are light for this destination.
Pack layers you can shed by midday plus one warm layer for the evening, a proper rain shell rather than an umbrella.
Flexible dates? June scores 6 points higher here — enough to change the trip.
December in Kos Island: expect compromises
Hardest · 1.4/10Temperatures hover around 16°C (61°F) — the kind of month where neither heat nor cold forces the schedule.
166 mm of rain signals a properly wet month, with only almost no days with 6+ hours of sunshine to count on — build indoor options into the schedule.
That is 1.4/10 on the same scale — 12th of 12 months, versus 10/10 for the best month here.
Expect low-season pricing, and crowds are light for this destination.
Pack layers you can shed by midday plus one warm layer for the evening, a proper rain shell rather than an umbrella.
If your dates are flexible, June is materially better in Kos Island — 8.6 points higher on the same scale.
