St Louis Regional Airport

KALN / ALN

Alton/St Louis, US

Last Updated
Apr 21, 22:50Z

Current Weather

Display Units
Recent 56 min ago
22:50Z

🌙 Night
VFR
Flight Rules
27°C
Temperature
Dewpoint: 9°C
14 kt
230° G22 kt
10 SM
Visibility
Ceiling
Unlimited
--
QNH
Altimeter Setting

Raw METAR

METAR KALN 212250Z 23014G22KT 10SM CLR 27/09 A2997

Weather Briefing

VFR

St Louis Regional Airport is currently reporting visual flight rules (VFR) conditions with clear skies and 10 SM visibility.

Wind Analysis

Winds are from the southwest (230°) at 14 knots with gusts to 22 knots. Runway 29 is favored with a 7-knot headwind and 12-knot crosswind component (gusting to 19 knots crosswind).

Visibility & Ceiling

Visibility is 10 SM. Skies are clear with unlimited ceiling.

Temperature & Moisture

Temperature is 27°C (81°F) with a dewpoint of 9°C, indicating very dry conditions.

Pilot Recommendations

Conditions are favorable for visual flight.

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

24-Hour Weather Evolution

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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
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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
ALN
11
29
17 ✈️
35

Runway Information

Runway Length Width Surface Heading Wind Component
11/29 8,101 ft 150 ft ASP 113°
6.4 kt 12.5 kt
117° angle
✈️ 17/35
Active: 17
6,500 ft 100 ft ASP 173°
7.0 kt 12.1 kt
60° angle
🟢 Active Runway: Best headwind component for current conditions
⬆️ Headwind: Favorable wind component
↔️ Crosswind: ≤10kt Safe, 11-15kt Caution, >15kt Challenging

Weather Statistics - KALN

8,822 observations | Sep 2025 - Apr 2026

Flight Rules Distribution

VFR
79.9%
MVFR
11.5%
IFR
4.6%
LIFR
3.9%

St Louis Regional Airport typically experiences VFR conditions 79.9% of the time, though instrument-rated pilots will find IFR weather present approximately 8.5% of observations. Prevailing winds are from the S averaging 8.5 knots, with gusts recorded up to 50 knots. Calm conditions occur 13.7% of the time. Temperature extremes range from -22°C to 36°C, reflecting significant seasonal variation. The best months for VFR flying are April, September, October.

Wind Analysis

Prevailing Direction: S (180°)
Average Speed: 8.5 kt
Maximum Recorded: 50 kt
Calm Winds: 13.7%
Direction Distribution:
N
10%
NE
4.9%
E
8.8%
SE
10.5%
S
21.7%
SW
6.2%
W
12.6%
NW
11.7%

Temperature Range

Average: 7.5°C
Range: -22°C to 36°C
-22°C 36°C

Visibility

Average: 9.4 SM
Below 3 SM: 1.2%
Fog Frequency: 1%

Best Months for VFR

April September October

Runway Wind Analysis

Runway 11/29
Favorable wind: 100%
Avg crosswind: 5.2 kt
Runway 17/35
Favorable wind: 100%
Avg crosswind: 4.7 kt

Statistics computed from 8,822 METAR observations (Sep 2025 - Apr 2026). Data sourced from official aviation weather services. Updated daily.

St Louis Regional Airport - Airport Information

Airport Details

ICAO Code: KALN
IATA Code: ALN
Type: medium airport
Status: active
Elevation: 544 ft MSL

Location

City: Alton/St Louis
Country: US
Latitude: 38.890301°
Longitude: -90.045998°
Time Zone: Etc/GMT+6

Runway Information

Runway 11/29
Length: 8,101 ft
Width: 150 ft
Surface: ASP
ILS: No
Runway 17/35
Length: 6,500 ft
Width: 100 ft
Surface: ASP
ILS: No

About St Louis Regional Airport

Overview

St Louis Regional Airport serves the Alton/St Louis metropolitan area as a medium-sized airport situated at 544 feet above mean sea level. Located at coordinates 38.890301, -90.045998, the airport provides critical aviation infrastructure for the regional transportation network with two substantial asphalt runways supporting diverse aircraft operations.

Flying Conditions

The airport experiences predominantly favorable flying conditions, with visual flight rules (VFR) conditions present 76.7% of the time. Temperature ranges from -16°C to 36°C create varied operational environments, while wind patterns are consistently southerly at an average of 8.4 knots with occasional gusts up to 50 knots. September, October, and January demonstrate the most consistent VFR weather patterns.

Notable Features

Both primary runways (11/29 and 17/35) offer extended lengths suitable for multiple aircraft types, with Runway 11/29 providing 8,101 feet and Runway 17/35 offering 6,500 feet of asphalt surface. Wind data indicates 100% favorable wind conditions for both runways, with modest average crosswind components of 4.6 and 5 knots respectively. Visibility averages 9.3 statute miles, with minimal instances of restricted visual conditions.

Approach Considerations

Pilots should anticipate predominantly southern wind patterns when planning approaches, with calm conditions occurring 14.4% of the time. Instrument meteorological conditions (IFR, MVFR) represent approximately 23.3% of observations, suggesting periodic need for instrument approach capabilities. The airport's elevation and consistent wind characteristics provide generally predictable approach conditions across seasons.

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.