Is Nakhon Si Thammarat sunnier than Ko Samui?

Ko Samui is the sunnier: about 2,342 hours of sunshine a year versus 2,056 — a difference of 286 hours.

Which is warmer, Nakhon Si Thammarat or Ko Samui?

Year-round daytime highs are similar: Nakhon Si Thammarat averages 30°C (86°F), Ko Samui 29°C (84°F).

Which is better in winter (November–February), Nakhon Si Thammarat or Ko Samui?

Ko Samui scores better across November–February: 71/100 average versus 68, with daytime highs around 28°C.

Which has the warmer sea, Nakhon Si Thammarat or Ko Samui?

Both peak at about 33°C (91°F); month-by-month sea temperatures for both are on this page.

Nakhon Si Thammarat vs Ko Samui: which is sunnier?

🇹🇭 Thailand vs 🇹🇭 Thailand · 113 km apart · long-term climate normals (NASA POWER, 2001–2020)

Ko Samui is the sunnier overall: about 2,342 hours of sunshine a year to Nakhon Si Thammarat's 2,056. Ko Samui has the higher Sunshine Score in 4 of 12 months; the other 8 are within 2 points.

Scores are the 0–100 Sunshine Score — sunshine, daytime warmth and dryness in one number, per month.

At a glance

	Nakhon Si Thammarat	Ko Samui
Sunshine hours / year	2,056	2,342
Sunniest month	February (83/100)	February (86/100)
Nov–Feb average score	68/100	71/100
Jun–Aug average score	63/100	65/100
Rain / year	2,361 mm	2,088 mm
Warmest sea	33°C / 91°F	33°C / 91°F
Peak midday UV	11 (extreme)	11 (extreme)

Nakhon Si Thammarat vs Ko Samui month by month

Month	Sunshine Score		Day high °C		Rain mm		Sea °C
Month	Nakhon Si Thammarat	Ko Samui	Nakhon Si Thammarat	Ko Samui	Nakhon Si Thammarat	Ko Samui	Nakhon Si Thammarat	Ko Samui
January	63	68	28°	28°	197	135	30°	29°
February	83	86	29°	28°	40	38	30°	30°
March	68	72	30°	29°	122	114	31°	30°
April	72	76	31°	30°	101	90	33°	32°
May	63	65	31°	30°	164	170	33°	33°
June	63	65	30°	30°	155	167	33°	31°
July	63	65	30°	29°	153	166	32°	31°
August	64	66	30°	29°	147	144	32°	31°
September	63	65	30°	29°	187	181	32°	30°
October	63	65	29°	28°	262	246	32°	31°
November	63	65	29°	28°	474	375	31°	30°
December	63	65	28°	28°	359	262	29°	29°

The sunnier month by month: Jan Ko Samui · Feb Ko Samui · Mar Ko Samui · Apr Ko Samui · May even · Jun even · Jul even · Aug even · Sep even · Oct even · Nov even · Dec even.

When to pick which

November–February: Ko Samui (average score 71/100 vs 68). Daytime highs are similar (29°C vs 28°C). See the winter sun ranking.
March–May: Ko Samui (average score 71/100 vs 68). Daytime highs are similar (31°C vs 30°C).
June–August: too close to call — Nakhon Si Thammarat averages 63/100, Ko Samui 65/100. Daytime highs are similar (30°C vs 29°C).
September–October: too close to call — Nakhon Si Thammarat averages 63/100, Ko Samui 65/100. Daytime highs are similar (30°C vs 29°C).

Sea temperature

Both seas peak at 33°C / 91°F. Swimmable water (21°C+): Nakhon Si Thammarat all year, Ko Samui all year. Month-by-month sea temperatures are in the table above.

Full month-by-month guides: Nakhon Si Thammarat weather by month · Ko Samui weather by month · Best time to visit Thailand.

More comparisons: Nakhon Si Thammarat vs Surat Thani · Nakhon Si Thammarat vs Trang · Nakhon Si Thammarat vs Krabi · Ko Samui vs Surat Thani · Ko Samui vs Rayong · Ko Samui vs Krabi · all head-to-heads