March scores 76/100 for outdoor ceremonies: very low rain risk (2 wet days, 21mm), 30°C afternoons cooling to about 26°C for the reception, and 12 hours of daylight for the photography schedule. October is the month to avoid at 23/100.
March outdoor ceremony score: 76/100
Climate normals for Koh Samui rescored on wedding-specific weighting. Once your date falls inside the 14-day window the live forecast on this page takes over.
Conditions on this page are recalculated from the latest forecast every time it is opened, for the current date in the location's own time zone. Showing .
| Best wedding month | March — 76/100 |
| Second choice | April — 76/100 |
| Month to avoid | October — 23/100 |
| Rain risk in the best month | Very low — rain on about 2 days |
| Guest comfort | 66/100 at 30°C |
| Reception temperature | ≈ 26°C after sunset in March |
| Photo light | 12h of sun across a 12h day |
| Months scoring 65+ | 4 of 12 |
March keeps seated guests at 30°C in the afternoon and around 26°C after sunset — the closest Koh Samui gets to a ceremony that needs neither shade structures nor patio heaters.
Rain falls on roughly 2 days in March (very low risk, 21mm). A simple marquee-on-standby is usually enough.
March gives 12 hours of daylight and about 12 hours of direct sun per day, so a late-afternoon ceremony puts portraits inside golden hour rather than after it.
October scores 23/100 for weddings in Koh Samui: 33°C highs, 129mm of rain and 30°C evenings make a fully outdoor plan fragile.
Scored on rain risk, guest comfort, evening temperature and photographic light — deliberately different weighting from the travel score.
| Month | Wedding score | Rain risk | Afternoon | Evening | Guest comfort | Photo light |
|---|---|---|---|---|---|---|
| January | 49/100 | Moderate (8 days) | 31°C | 27°C | 62/100 | 59/100 |
| February | 68/100 | Low (4 days) | 30°C | 26°C | 66/100 | 87/100 |
| March | 76/100 | Very low (2 days) | 30°C | 26°C | 66/100 | 100/100 |
| April | 76/100 | Very low (2 days) | 30°C | 26°C | 66/100 | 100/100 |
| May | 66/100 | Low (4 days) | 31°C | 27°C | 62/100 | 89/100 |
| June | 56/100 | Low (6 days) | 32°C | 28°C | 58/100 | 75/100 |
| July | 46/100 | Moderate (8 days) | 32°C | 29°C | 58/100 | 61/100 |
| August | 36/100 | Moderate (10 days) | 33°C | 30°C | 54/100 | 48/100 |
| September | 28/100 | Moderate (12 days) | 33°C | 30°C | 53/100 | 33/100 |
| October | 23/100 | High (14 days) | 33°C | 30°C | 51/100 | 19/100 |
| November | 25/100 | High (14 days) | 32°C | 29°C | 55/100 | 18/100 |
| December | 31/100 | Moderate (12 days) | 32°C | 28°C | 58/100 | 32/100 |
Wedding weather is scored differently from travel weather: seated guests in formalwear tolerate a narrower band than sightseers, and the ceremony hour matters more than the daily average. Each month in Koh Samui is scored 0–100 on the weighting below.
| Factor | Weight | What it measures |
|---|---|---|
| Dry conditions | 38% | Share of days with measurable rain — the single factor most likely to force a backup plan. |
| Guest comfort | 27% | Distance from a 22°C daytime ideal, with an extra penalty for humid heat above 24°C. |
| Evening temperature | 20% | Modelled reception-hour temperature against an 18°C ideal for an outdoor evening. |
| Photo light | 15% | Sunshine hours and daylight length, which set the length and quality of the golden hour window. |
Based on long-run climate averages rather than a forecast. Plan the ceremony around the golden hour — see golden hour times for Koh Samui linked below.
March, at 76/100. It combines very low rain risk with 30°C afternoons and roughly 26°C evenings, which is the most forgiving combination Koh Samui offers for seated guests.
October scores 23/100: 33°C highs, 129mm of rain over about 14 days and 30°C evenings make a fully outdoor plan fragile.
In March rain falls on roughly 2 of 30 days, so the single-day probability is about 7%. In October that rises to about 47%.
A marquee on standby is usually enough in March, where rain risk is very low. Outside the 4 months scoring 65 or higher, book real covered space.
March gives 12 hours of daylight and about 12 hours of direct sun. Put portraits in the final 60–90 minutes of daylight so they land inside golden hour rather than after it.