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Koh Samui in October: weather, sea & travel advice

This month's data profile

Rain shapes the decision

Koh Samui in October is climatically well suited to beach holidays. The average daily high is around 28 °C, and the sea is about 29 °C. With about 28 rainy days it is very wet.

Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.

Rank among 12 monthly averages

56/100 · #7

Warmth

Dryness

#12

Sun

#10

Sea warmth

Published best categories: none

Koh Samui · OctoberPhoto: Sonia Selivonchik · CC BY-SA 4.0

Average high: 28 °C
Average low: 27 °C
Sea: 29 °C
Rainy days (est.): 28 rainy days (est.)
Sun (est.): 6 h/day
Humidity: 82 %

Climate evidence with direct month comparison

The highlighted row is the selected month. Precipitation total and rainy days are separate monthly averages.

Climate averages for Koh Samui: selected and adjacent months
Month	Avg high °C	Avg low °C	Rainy days (est.)	Precipitation mm	Sun h/day (est.)	Humidity %	Wind m/s	Sea °C	Score
September	29	27	27	181	6.3	81	4.0	29	56
October (selected)	28	27	28	265	5.6	82	3.4	29	56
November	28	27	25	396	5.2	81	4.3	29	57

How do the previous and next months compare?

Baseline: October (56/100)

Positive and negative values show the change from the selected month.

	Score Δ	Average high Δ	Average low Δ	Rainy days Δ	Rain Δ	Sun Δ	Humidity Δ	Wind Δ	Sea Δ
September	±0	+0.4 °C	±0 °C	-1.3	-84.3 mm	+0.7 h	-0.5 %	+0.6 m/s	+0.2 °C
November	+1	-0.2 °C	±0 °C	-3.4	+130.6 mm	-0.4 h	-0.3 %	+0.8 m/s	-0.4 °C

All twelve months in context

JanGood73 FebExcellent83 MarGood75 AprLimited62 MayLimited50 JunLimited52 JulLimited54 AugLimited55 SepLimited56 OctLimited56 NovLimited57 DecLimited64

Rainy days (estimated)

Sunshine hours (estimated)h/day

Average daily high°C

Sea temperature°C

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Where to stay in Koh Samui

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Useful next decisions

Koh Samui · Month by month

Palawan · October Boracay · October Ko Phi Phi · October Ambergris Caye · October

Frequently asked questions

How warm is Koh Samui in October?

The average daily high is around 28 °C, with an average daily low of about 27 °C.

Can you swim in Koh Samui in October?

The sea is about 29 °C (very warm).

Does it rain a lot in Koh Samui in October?

The curated estimate is about 28 rainy days per month, not a directly measured long-term average. Total precipitation averages around 265 mm for the month. A rainy day does not mean all-day rain.

When is the best time to visit Koh Samui?

By the climate score, January, February, March and December are the strongest months for Koh Samui. For a beach trip: January, February, March and December. October is not among them.