Lemhi County Airport

KSMN / SMN

Salmon, US

Last Updated
Apr 23, 08:56Z

Current Weather

Display Units
Fresh 27 min ago
08:56Z

☀️ Day
MVFR
Flight Rules
3°C
Temperature
Dewpoint: 2°C
0 kt
10 SM
Visibility
1,600 ft
Ceiling
Above Ground Level
1012 hPa
QNH
Altimeter Setting

Raw METAR

METAR KSMN 230856Z AUTO 00000KT 10SM -RA BKN016 OVC050 03/02 A2989 RMK AO2 SLP126 P0000 60003 T00330022 51009

Clouds - Visual Profile

12,000ft
9,000ft
6,000ft
3,000ft
Ground
Field Elev: 4,043 ft
BKN 1,600 ft AGL
OVC 5,000 ft AGL
☁️
BKN
Broken (5/8-7/8 sky coverage)
1,600 ft
AGL (Above Ground)
5,643 ft AMSL
☁️
OVC
Overcast (8/8 sky coverage)
5,000 ft
AGL (Above Ground)
9,043 ft AMSL

Weather Briefing

MVFR

Lemhi County Airport is currently reporting marginal VFR (MVFR) conditions with overcast skies at 5,000 feet and 10 SM visibility.

Wind Analysis

Winds are calm, presenting no crosswind concerns for any runway.

Visibility & Ceiling

Visibility is 10 SM. The ceiling is 1600 feet AGL (broken), placing conditions in the MVFR category.

Temperature & Moisture

Temperature is 3°C (37°F) with a dewpoint of 2°C. The temperature-dewpoint spread is very narrow, indicating saturated or near-saturated air. Fog formation or low cloud development is likely.

Forecast Outlook

The TAF forecast covers the next 24 hours. The forecast shows a transition between VFR and IFR conditions. Pilots should monitor the forecast closely and have an alternate airport plan. Expected weather includes: Light Rain, Light RASN, Mist. There is a 30% probability of IFR conditions with Light RASN, Mist between 17:00Z and 20:00Z.

Pilot Recommendations

VFR pilots should exercise caution. Consider filing IFR if instrument rated, or postponing the flight if conditions are expected to deteriorate further. The narrow temperature-dewpoint spread creates risk of fog formation, particularly during evening and early morning hours. The forecast indicates conditions may deteriorate. Ensure you have fuel reserves and a viable alternate airport.

This briefing is generated from real-time METAR and TAF data. Always verify with official sources before flight.

QNH
1012 hPa
Sea Level Pressure
For altitude above MSL
QFE
877 hPa
Field Pressure
Height above aerodrome (4,043 ft)
Pressure Alt
4,081 ft
QNE Reference
Standard: 1013 hPa
Density Altitude: 3,611 ft
ISA Deviation: -3.9°C

Forecast (TAF)

View Full TAF
Raw TAF
TAF KSMN 230520Z 2306/2406 VRB05KT 6SM -RA BKN035 OVC050 FM230900 19006KT P6SM VCSH BKN027 PROB30 2317/2320 2SM -RASN BR BKN035 FM232000 35012G20KT P6SM VCSH BKN060
Upcoming Changes (Next 12 Hours)
09:23Z BASE
+0h
VFR VRB 5 kt
Visibility: 6SM
Ceiling: 3,500 ft
Light Rain
17:00Z PROB30
+8h
IFR
Visibility: 2SM
Ceiling: 3,500 ft
Light RASN, Mist
20:00Z FM232000
+11h
VFR 350° 12 kt
Visibility: >6SM
Ceiling: 6,000 ft

24-Hour Weather Evolution

Loading weather data...
Data Sources
  • • Current conditions from METAR observations
  • • Historical data from past 24 hours
  • • No forecast or predicted data included
  • • Data updated with each new METAR report
Chart Features
  • • Hover for exact values and timestamps
  • • Click legend items to toggle data series
  • • Zoom and pan for detailed analysis
  • • Units automatically converted to preferences
Note: Future values beyond current TAF validity are estimates based on climatological data and trends. Always verify with current forecasts before flight operations.

Airport Runway Layout

N
SMN
17
35

Runway Information

Runway Length Width Surface Heading Wind Component
17/35 5,150 ft 60 ft ASP 188°
0.0 kt 0.0 kt
172° angle
🟢 Active Runway: Best headwind component for current conditions
⬆️ Headwind: Favorable wind component
↔️ Crosswind: ≤10kt Safe, 11-15kt Caution, >15kt Challenging

Weather Statistics - KSMN

5,784 observations | Sep 2025 - Apr 2026

Flight Rules Distribution

VFR
83.4%
MVFR
6.2%
IFR
3.1%
LIFR
7.3%

Lemhi County Airport enjoys predominantly VFR conditions, with visual flight rules prevailing 83.4% of the time. Prevailing winds are from the N averaging 6.2 knots. Calm conditions occur 51.5% of the time. Temperature extremes range from -17°C to 28°C, reflecting significant seasonal variation. The best months for VFR flying are October, March, April.

Wind Analysis

Prevailing Direction: N (0°)
Average Speed: 6.2 kt
Maximum Recorded: 28 kt
Calm Winds: 51.5%
Direction Distribution:
N
10.4%
NE
2.8%
E
4.3%
SE
7.8%
S
9.2%
SW
5.5%
W
3.6%
NW
4.9%

Temperature Range

Average: 3.6°C
Range: -17°C to 28°C
-17°C 28°C

Visibility

Average: 9.5 SM
Below 3 SM: 2.4%
Fog Frequency: 4%

Best Months for VFR

October March April

Runway Wind Analysis

Runway 17/35
Favorable wind: 100%
Avg crosswind: 3.3 kt

Statistics computed from 5,784 METAR observations (Sep 2025 - Apr 2026). Data sourced from official aviation weather services. Updated daily.

Lemhi County Airport - Airport Information

Airport Details

ICAO Code: KSMN
IATA Code: SMN
Type: medium airport
Status: active
Elevation: 4,043 ft MSL

Location

City: Salmon
Country: US
Latitude: 45.122233°
Longitude: -113.881960°
Time Zone: Etc/GMT+8

Runway Information

Runway 17/35
Length: 5,150 ft
Width: 60 ft
Surface: ASP
ILS: No

Nearby Airports

VFR MVFR IFR LIFR No Data

About Lemhi County Airport

Overview

Lemhi County Airport serves the Salmon, Idaho region as a medium-sized airport situated at an elevation of 4,043 feet MSL. Located at coordinates 45.122233, -113.881960, the airport provides critical aviation infrastructure in a mountainous region of the northwestern United States. Its single runway 17/35 offers 5,150 feet of asphalt surface for regional and general aviation operations.

Flying Conditions

Weather conditions at Lemhi County Airport demonstrate significant variability, with visual flight rules (VFR) prevailing 77.8% of the time. Temperature ranges from -15°C to 28°C, creating diverse flying environments throughout the year. October, September, and November present the most consistently favorable VFR conditions, while visibility averages 9.2 statute miles with occasional reduced visibility periods.

Notable Features

The airport's high elevation and mountainous terrain demand careful navigation and performance planning. Wind patterns are predominantly from the north (0°), with an average speed of 5.7 knots and potential gusts up to 28 knots. Calm wind conditions occur 53.8% of the time, which provides relatively stable approach and departure environments.

Approach Considerations

Runway 17/35 demonstrates excellent wind alignment, with favorable wind conditions 100% of the time and an average crosswind of only 2.9 knots. Pilots should anticipate potential instrument meteorological conditions (IMC), as IFR and LIFR conditions combine for approximately 14.5% of observations. Careful preflight planning and awareness of seasonal weather variations are recommended for safe operations.

Data Sources & Accuracy: Airport information sourced from OurAirports.com, a collaborative database of worldwide airport data. Weather data from official aviation weather services including NOAA Aviation Weather Center and international METAR/TAF providers. Information is updated regularly but pilots should always verify current conditions and NOTAMs through official channels before flight operations.

Official Data Sources

Weather NOAA Aviation Weather Center • International METAR/TAF Network
Airports OurAirports.com • Public domain airport database
NOTAMs FAA NOTAM System • ICAO NOTAM Distribution
Last updated: Jan 1, 1970 12:00 AM UTC

Disclaimer: Data is provided for informational purposes only. Pilots must verify all information through official sources before flight operations. Weather conditions change rapidly; always obtain a current briefing from approved weather services.