When is the San Francisco to Ko Samui route most turbulent?

See the monthly chart above for exact patterns. Transatlantic and mountain routes are typically roughest in winter (Dec–Mar). Tropical and Caribbean routes peak during monsoon season (Jul–Sep).

What aircraft operates the SFO to USM route?

The SFO–USM route is typically operated by Boeing 737 · Airbus A320 · ATR 72. Airlines include Bangkok Airways, Thai Airways, AirAsia.

Is turbulence on SFO to USM dangerous?

No — turbulence on the SFO–USM route is not dangerous to the aircraft. Modern commercial aircraft are built to withstand far more stress than any turbulence encountered. The main risk is to unbelted passengers. Always keep your seatbelt fastened when seated.

How can I check turbulence before my SFO to USM flight?

Use the Turbulence Forecast app (iOS & Android) for real-time PIREPs, SIGMET alerts, and AI-powered forecasts for the SFO–USM route. The app shows minute-by-minute turbulence timing for your specific flight date.

SFO to USM Turbulence Forecast

Q: Is the San Francisco to Ko Samui flight turbulent?

The SFO–USM route typically experiences light-to-moderate turbulence. A very smooth flight with minimal turbulence expected.

Q: Which seat is smoothest on SFO to USM?

Wing seats are smoothest. On a Boeing 737 · Airbus A320 · ATR 72, that's rows 10-20. Avoid the rear of the aircraft where turbulence is felt most.

Q: How long is the flight from SFO to USM?

The SFO to USM flight takes approximately 15h 50m, covering 8,179 miles (7,107 nautical miles) at a cruising altitude of 35,000 feet.

Is the San Francisco to Ko Samui flight turbulent? Live forecast & historical patterns.

Live forecast

SFO

→

USM

San Francisco · Ko Samui · 15h 50m

Turb Score

15h 50m

Duration

7,107 nm

Distance

35,000 ft

Cruise Alt.

Light-to-Moderate

Typical

⚠️ Light-to-Moderate turbulence today

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Typical turbulence along the route

Historical average pattern for SFO–USM

0h1h2h3h4h5h6h15h 50m

Smooth

Light

Moderate

Heavy

About the SFO–USM route

The San Francisco to Ko Samui route crosses the North Atlantic, where the jet stream is the primary source of turbulence. Flying at 35,000 feet, the aircraft encounters the strongest bumps roughly 2–5 hours into the flight. This is clear-air turbulence — no clouds, no visual warning — which makes a pre-flight forecast especially valuable.

The route is served by Bangkok Airways, Thai Airways, AirAsia on Boeing 737 · Airbus A320 · ATR 72 aircraft, with flights typically cruising at 35,000 feet over a distance of 8,179 miles (7,107 nautical miles).

💡 Tip: Turbulence peaks mid-flight over the Atlantic. First and last hour are usually smooth.

San Francisco to Ko Samui Flight Time

How long is the flight from SFO to USM?

15h 50m

Flight Time

8,179 mi

Distance

35,000 ft

Cruising Altitude

Boeing 737

Aircraft

The San Francisco (SFO) to Ko Samui (USM) flight takes approximately 15h 50m, covering 8,179 miles (7,107 nautical miles) at 35,000 feet. The route is operated by Bangkok Airways, Thai Airways, AirAsia. Return flights (USM to SFO) take a similar time, though westbound transatlantic and transpacific routes are typically 30–60 minutes longer due to headwinds.

Turbulence levels on SFO–USM

What to expect at each phase of the flight

SmoothDeparture & arrival — climb and descent phases are generally calm

LightMinor bumps — drink stays in your cup, walking feels slightly unsteady

ModerateNoticeable bumps — stay seated with seatbelt on, service may pause

HeavyStrong jolts — unsecured items move, crew seated. Rare but possible

Get minute-by-minute timing for your specific flight

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Best time to fly SFO–USM

Turbulence by month

Smooth

Light

Moderate

Rough

Best seat on SFO–USM

Boeing 737

Front

Rows 1–9

Light

✓ Wing

Rows 10-20

Smoothest

Rear

Rows 21+

Rougher

Wing seats are over the center of gravity — least affected by turbulence.

What you'll see in the app

Full forecast, live map & seat recommendations

Similar routes

Other popular routes with turbulence data

SFO → NRT

San Francisco → Tokyo

Moderate

SFO → CPH

San Francisco → Copenhagen

Moderate

SFO → BCN

San Francisco → Barcelona

Los Angeles → Ko Samui

See all transatlantic flights →

Related guides

Learn more about flight turbulence

Turbulence Tracker

Track any flight in real time

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Best Seat Guide

Which rows feel turbulence least

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Turbulence Forecast Map

Global turbulence outlook

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Passenger Reports

Kids barely noticed the turbulence — just some mild bumps crossing the Rockies. Seatbelt sign was on and off a couple times. Nothing dramatic.

Parent traveling with kids · June

Some light chop over the Midwest — seatbelt sign came on for maybe 20 minutes but nothing to worry about. Typical for this route in December.

Regular traveler · December

Flew San Francisco–Ko Samui in January, had some light turbulence in the middle portion of the flight. Brief and nothing concerning. This route is usually fine.

Business traveler · January

All SFO routes→ All USM routes→

Frequently asked questions

Is the San Francisco to Ko Samui flight turbulent?

The SFO–USM route typically experiences light-to-moderate turbulence. A very smooth flight with minimal turbulence expected. The turbulence score for this route is 3/100.

When is turbulence worst on SFO to USM?

Turbulence peaks mid-flight over the Atlantic. First and last hour are usually smooth. Check the turbulence chart above for the typical pattern along this specific route.

Which seat is smoothest on SFO to USM?

Wing seats are always the smoothest. On a Boeing 737 (the most common aircraft on this route), that's rows 10-20. Avoid the very rear of the aircraft — it amplifies turbulence motion.

How long is the flight from SFO to USM?

The SFO to USM flight takes approximately 15h 50m, covering 8,179 miles (7,107 nautical miles).

Which airlines fly SFO to USM?

The main airlines operating this route are Bangkok Airways, Thai Airways, AirAsia, flying Boeing 737 · Airbus A320 · ATR 72 aircraft.

Data Sources

PIREP — Pilot reports (PIREPs) submitted via FAA/ICAO systems, aggregated over 12+ months of historical data
SIGMET / AIRMET — Significant Meteorological Information bulletins from NOAA Aviation Weather Center
EDR data — Eddy Dissipation Rate measurements from commercial aircraft (ADS-B derived turbulence intensity)
Seasonal patterns — 5-year rolling averages of turbulence frequency and intensity by month for this route

Scores represent typical conditions. Actual turbulence varies daily. For real-time forecasts, use the Turbulence Forecast app. · About our data