United Airlines DEN SDF UA421
United Airlines · Live forecast
DEN → SDF
UA421 · Mar 16, 2026 · 17:25 MD
74
Calm Score
"Mostly smooth — one short bumpy section you'll handle."
4h 34m
Duration
887 nm
Distance
35,000 ft
Cruise Altitude
HIGH
Confidence
Turbulence comfort along route
Comfort score combines turbulence probability with intensity — higher means rougher
Smooth Light Moderate Severe
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We know turbulence can feel scary — especially on long flights. This report is built for you: what bumps feel like, when they happen, and why you'll be completely safe. 1 in 3 passengers feel exactly like you.
Right now on your route
Live pilot reports from aircraft flying DEN → SDF
15 pilot reports along this route
10 / 15
Reporting smooth
2 / 15
Light turbulence
3
Moderate or worse
Latest pilot reports
Smooth
DEN UA /OV DEN/TM 0026/FLDURGD/TP E75L/IC NEG
8m ago
Smooth
COS UA /OV BRK265051/TM 0023/FL240/TP B738/TB NEG/RM ZDVWC-26
11m ago
Smooth
MCK UA /OV HCT/TM 0022/FL300/TP B38M/TB NEG/RM ZDVWC-08
12m ago
Smooth
SNY UA /OV SNY170020/TM 0018/FL370/TP A320/TB NEG/RM ZDVWC-16
16m ago
Moderate
BAK UA /OV KBAK/TM 0012/FL010/TP C750/SK SCT065/WX 10/TA 20/WV 18015G24/TB MODERATE/IC NEG/RM DURD AIRCRAFT REPORTED MODERATE TURBULENCE BELOW 5000FT LOSS AND GAIN -/+ 15 KNOTS ON FINAL BELOW 1000FT
22m ago
AI-powered flight briefing
3,500 data points analyzed · HIGH confidence
Your Flight

We analysed more than 3,500 data points along your route from Denver International Airport, Denver to Louisville Muhammad Ali International Airport, Louisville.

Your Journey Beta

Some bumpy patches are scattered throughout the flight. Keep your seatbelt fastened when seated.

Your route takes you over the Rocky Mountains and over the Appalachian Mountains – these areas can sometimes cause light turbulence.

Mostly Smooth

Overall conditions look mostly smooth with occasional light bumps. Nothing to worry about.

Takeoff

Takeoff should feel smooth with possible light bumps, with calm conditions around the airport.

Winds Aloft

Winds at cruising altitude are about 87 knots. These winds are favorable and may get you there a few minutes early.

Landing

Landing should feel a bit bumpy on descent with typical approach conditions.

You're in Safe Hands

If you feel nervous at any point, remember that turbulence is expected, safe, and part of normal flying. The crew is monitoring everything, and the aircraft is built to handle far more than anything you will feel. Have a safe and calm flight.

Relaxation Exercises
ZeroTurb Index (ZTI): Powered by our turbulence prediction algorithm combining atmospheric Richardson Number, wind shear analysis, temperature gradients, and geomagnetic activity. Learn more
Live data from ECMWF global forecast models · 12 atmospheric pressure levels · Updated every 6 hours
Flight Timeline 4h 34min
Maximum turbulence expected per segment
Takeoff
Light
0:30-0:57
Light
0:57-1:24
Light
1:24-1:51
Light
1:51-2:18
Light
2:18-2:45
Light
2:45-3:12
Light
3:12-3:38
Light
3:38-4:04
Moderate
Landing
Moderate
Smooth
Light
Moderate
Severe
Longer bars indicate higher turbulence intensity. Values shown are the maximum for each time segment.
Airport conditions
Live weather at departure and arrival
DEN Denver International Airport — Departure
Visibility
0 mi
Wind
6 kt (30°)
Sky
Few
Temperature
-6°C
Conditions
LIFR — Very poor visibility, significant delays expected
SDF Louisville Muhammad Ali International Airport — Arrival
Wind
24 kt G38 (190°)
Sky
Broken
Temperature
23°C
Conditions
VFR — Clear conditions, no delays expected
Your flight details
Departure timing and aircraft information
Evening Flight Departure
Time of day
Evening Flight
Tip
Evening and night flights typically offer smoother conditions as thermal activity subsides and the atmosphere stabilizes after sunset.
When
Today
Data sources & our approach
ZeroTurb's Custom Algorithm: Our proprietary ZeroTurb Index (ZTI) combines three meteorological indices weighted by their predictive accuracy — giving you transparent, passenger-focused turbulence probability instead of vague categories.

This forecast integrates data from:

Disclaimer: This forecast is for informational purposes only. Always consult official aviation weather sources and follow ATC guidance.