Keflavik International Airport turbulence forecast
Keflavik, Iceland
KEF (Keflavik, Iceland) sits at 63.99°N, 22.61°W, 171 ft elevation — coastal with the Greenland ice cap nearby.
About KEF
Major airport serving Keflavik, Iceland.
- Climate
- Subpolar — long winters, short cool summers
- Nearby terrain
- Greenland ice cap
- Geography
- Coastal — marine-influenced airmass
What to expect on departures
Computed from KEF's geography and climate
The jet stream meanders across this latitude seasonally — KEF sees its strongest CAT exposure in December–February, when the polar jet pushes equatorward and routes intersect it more often. June-onwards departures climb into cleaner upper-level flow. The Greenland ice cap sit upwind of KEF on prevailing flow days, generating mountain-wave turbulence that can extend several hundred kilometres downwind at cruise level. The lee-wave risk is highest when December–February winds at FL300 cross the Greenland ice cap at near-perpendicular angles. KEF's coastal position means departures often transit from the cool marine boundary layer into warmer continental air within minutes of takeoff — a brief but reliable bumpy transition on warm-season afternoons when the sea breeze is set up.
Climbout notes
Standard Instrument Departures (SIDs) often route around terrain; on strong-wind days, low-level turbulence in the lee of the hills is common in the first few thousand feet.
Seasonal pattern
Winter (December–February) brings the strongest jet-stream activity — that's when long-haul departures most often log clear-air turbulence at cruise. Mountain-wave activity near the Greenland ice cap peaks in the cold season when upper-level winds blow hardest across the range.
- Peak turbulence
- November–February (strong jet)
- Typically calmest
- May–September
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KEF turbulence FAQ
Is turbulence common on flights from KEF?
Keflavik International Airport is best described as a mountain-wave sensitive airport. The jet stream meanders across this latitude seasonally — KEF sees its strongest CAT exposure in December–February, when the polar jet pushes equatorward and routes intersect it more often.
When is turbulence worst for Keflavik flights?
Winter (December–February) brings the strongest jet-stream activity — that's when long-haul departures most often log clear-air turbulence at cruise. Peak turbulence window: November–February (strong jet). Typically calmest: May–September.
Does the terrain around Keflavik affect turbulence?
Yes — the Greenland ice cap lie close enough to generate mountain-wave turbulence on days with strong upper-level winds. These waves can propagate hundreds of kilometres downwind, so they sometimes affect cruise even after you've left the immediate area.
How accurate are Turbcast forecasts?
We combine live NOAA Aviation Weather Center data (PIREPs, SIGMETs, AIRMETs) with physics-based Ellrod and Richardson-number calculations derived from Open-Meteo pressure-level wind and temperature data. If a source is unavailable for a waypoint we show an em dash rather than invent a number.
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