Rayong vs Ko Samui: which is sunnier?
🇹🇭 Thailand vs 🇹🇭 Thailand · 363 km apart · long-term climate normals (NASA POWER, 2001–2020)
Rayong and Ko Samui are virtually tied for annual sunshine — about 2,377 vs 2,342 hours a year. Rayong 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
| Rayong | Ko Samui | |
|---|---|---|
| Sunshine hours / year | 2,377 | 2,342 |
| Sunniest month | February (88/100) | February (86/100) |
| Nov–Feb average score | 85/100 | 71/100 |
| Jun–Aug average score | 65/100 | 65/100 |
| Rain / year | 2,065 mm | 2,088 mm |
| Warmest sea | 32°C / 90°F | 33°C / 91°F |
| Peak midday UV | 10 (very high) | 11 (extreme) |
Rayong vs Ko Samui month by month
| Month | Sunshine Score | Day high °C | Rain mm | Sea °C | ||||
|---|---|---|---|---|---|---|---|---|
| Rayong | Ko Samui | Rayong | Ko Samui | Rayong | Ko Samui | Rayong | Ko Samui | |
| January | 86 | 68 | 28° | 28° | 35 | 135 | 28° | 29° |
| February | 88 | 86 | 29° | 28° | 25 | 38 | 29° | 30° |
| March | 81 | 72 | 29° | 29° | 64 | 114 | 30° | 30° |
| April | 76 | 76 | 30° | 30° | 91 | 90 | 31° | 32° |
| May | 65 | 65 | 30° | 30° | 224 | 170 | 32° | 33° |
| June | 65 | 65 | 29° | 30° | 290 | 167 | 31° | 31° |
| July | 65 | 65 | 29° | 29° | 324 | 166 | 30° | 31° |
| August | 65 | 66 | 29° | 29° | 293 | 144 | 30° | 31° |
| September | 65 | 65 | 29° | 29° | 360 | 181 | 30° | 30° |
| October | 65 | 65 | 29° | 28° | 252 | 246 | 31° | 31° |
| November | 78 | 65 | 29° | 28° | 80 | 375 | 30° | 30° |
| December | 88 | 65 | 29° | 28° | 27 | 262 | 29° | 29° |
The sunnier month by month: Jan Rayong · Feb even · Mar Rayong · Apr even · May even · Jun even · Jul even · Aug even · Sep even · Oct even · Nov Rayong · Dec Rayong.
When to pick which
- November–February: Rayong (average score 85/100 vs 71). Daytime highs are similar (29°C vs 28°C). See the winter sun ranking.
- March–May: Rayong (average score 74/100 vs 71). Daytime highs are similar (30°C vs 30°C).
- June–August: too close to call — Rayong averages 65/100, Ko Samui 65/100. Daytime highs are similar (29°C vs 29°C).
- September–October: too close to call — Rayong averages 65/100, Ko Samui 65/100. Daytime highs are similar (29°C vs 29°C).
Sea temperature
Ko Samui's sea gets warmer: 33°C / 91°F at its peak vs 32°C. Swimmable water (21°C+): Rayong all year, Ko Samui all year. Month-by-month sea temperatures are in the table above.
Full month-by-month guides: Rayong weather by month · Ko Samui weather by month · Best time to visit Thailand.
More comparisons: Rayong vs Bangkok · Rayong vs Phu Quoc · Ko Samui vs Nakhon Si Thammarat · Ko Samui vs Surat Thani · Ko Samui vs Krabi · all head-to-heads