Great Circle Distance between Heathrow and Samui Airport is 6,148 miles, with a flight time of approx 12.5 hrs. Koh Samui's IATA airport code is USM.
Show Samui Airport on map.
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Climate:
In Ko Samui, the climate is tropical, hot all year round, with a long rainy season due to the monsoon of Southeast Asia, which runs from May to mid-January, and a drier season from mid-January to April. The driest months are February and March, when, however, some showers can sometimes occur. The temperature is high throughout the year, around 30°C during the day and 25°C at night. The coolest months are December and January, while from February to May, an increase in temperature is observed, though less marked than in the mainland of Thailand; April and May are, albeit slightly, the hottest months. In the summer months, the heat continues to be intense and sultry, though tempered by sea breezes. The amount of sunshine is good in the driest period, from mid-January to April, while in the rest of the year, the sun often shines, but it alternates with some cloudiness, more or less widespread, and associated with rain showers.
BA Tier Points Earned
| Route 1 | LGW‑BKK
(BA)  | BKK‑USM
(PG)  |
|
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 20 | | | | 20 | 40 |
| WTP | 90 | | | | 90 | 180 |
| Business | 140 | | | | 140 | 280 |
| First | 210 | | | | 210 | 420 |
| |
| Route 2 | LHR‑BKK
(TG)  | BKK‑USM
(PG) |
|
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 0 | | | | 0 | 0 |
| WTP | | | | | | |
| Business | 0 | | | | 0 | 0 |
| First | | | | | | |
| |
| Route 3 | LHR‑HKG
(BA) | HKG‑USM
(CX)  |
|
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 20 | 5 | | | 25 | 50 |
| WTP | 90 | 25 | | | 115 | 230 |
| Business | 140 | 40 | | | 180 | 360 |
| First | 210 | 60 | | | 270 | 540 |
| |
| Route 4 | LHR‑SIN
(BA) | SIN‑USM
(PG) |
|
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 80 | | | | 80 | 160 |
| WTP | 100 | | | | 100 | 200 |
| Business | 160 | | | | 160 | 320 |
| First | 240 | | | | 240 | 480 |
| |
| Route 5 | LGW‑BKK
(BA) | BKK‑HKG
(CX) | HKG‑USM
(CX) |
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 20 | 5 | 5 | | 30 | 60 |
| WTP | 90 | 25 | 25 | | 140 | 280 |
| Business | 140 | 40 | 40 | | 220 | 440 |
| First | 210 | 60 | 60 | | 330 | 660 |
| |
| Route 6 | LHR‑BKK
(TG) | BKK‑HKG
(CX) | HKG‑USM
(CX) |
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 0 | 5 | 5 | | 10 | 20 |
| WTP | | 25 | 25 | | 50 | 100 |
| Business | 0 | 40 | 40 | | 80 | 160 |
| First | | 60 | 60 | | 120 | 240 |
| |
| Route 7 | LHR‑DOH
(QR)  | DOH‑BKK
(QR) | BKK‑USM
(PG) |
| TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 20 | 20 | | | 40 | 80 |
| WTP | | | | | | |
| Business | 140 | 140 | | | 280 | 560 |
| First | 210 | 210 | | | 420 | 840 |
| |
| Route 8 | LHR‑DOH
(QR) | DOH‑BKK
(QR) | BKK‑HKG
(CX) | HKG‑USM
(CX) | TOTAL
(SGL) | TOTAL
(RTN) |
|---|
| Economy | 20 | 20 | 5 | 5 | 50 | 100 |
| WTP | 20 | 20 | 25 | 25 | 65 | 130 |
| Business | 140 | 140 | 40 | 40 | 360 | 720 |
| First | 210 | 210 | 60 | 60 | 540 | 1080 |
| |
Economy Tier Points shown are based on fully flexible fares. 'Low' Economy earns 50% of the shown amount. 'Lowest' Economy fares earn 25% of shown amount.
When journey is booked in World Traveler Plus or First and those cabins don't exist on particular legs, the next cabin down will be used on those legs for points collection.
When booking with BA, tier points can be earned on the following 
Oneworld Alliance ® airlines:
Alaska Airlines, 
American Airlines, British Airways, Cathay Pacific, 
Fiji Airways, 
Finnair, 
Iberia, 
Japan Airlines, 
Malaysia Airlines, 
Qantas, Qatar Airways, 
Royal Air Maroc, 
Royal Jordanian, 
SriLankan Airlines
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