How to Read a METAR for the Part 107 Exam (With Examples)

How to Read a METAR for the Part 107 Exam (With Examples)

METAR (Meteorological Aerodrome Report) is the standard format for reporting weather at airports worldwide. The Part 107 exam includes 15-20% weather questions, and most require METAR interpretation. Many pilots avoid METAR because it looks like alphabet soup. But once you understand the structure, it's logical and learnable.

This guide teaches you METAR decoding step-by-step using real examples. By the end, you'll confidently decode any METAR and make safe Part 107 operational decisions.

METAR Structure: The Overall Format

Every METAR follows the same structure. Here's a real example:

KORD 121856Z 09014G25KT 10SM FEW250 23/14 A2990 RMK AO2 SLP114 T02330139

Breaking it down left to right, we have eight sections:

1. Station ID (KORD): Chicago O'Hare International Airport
2. Time (121856Z): Day 12, 1856 UTC (Zulu time)
3. Wind (09014G25KT): From 090°, 14 knots, gusts to 25 knots
4. Visibility (10SM): 10 statute miles
5. Weather Phenomena (none in this report): No rain, snow, etc.
6. Cloud Coverage (FEW250): Few clouds at 25,000 feet
7. Temperature/Dewpoint (23/14): 23°C / 14°C
8. Altimeter (A2990): 29.90 inches of mercury

Let's examine each section in detail.

Section 1: Station ID

The first element is always the airport identifier. U.S. airports start with 'K'. Examples:

• KJFK = New York JFK
• KLAX = Los Angeles International
• KDEN = Denver International
• KSEA = Seattle-Tacoma

For Part 107, you're typically checking weather for your operation location or nearby airports. The station identifier tells you which airport reported the weather.

Section 2: Report Time

Format: DDHHMMZ

Example: 121856Z

• 12 = Day 12 of the month
• 18 = Hour 18 (6:00 PM)
• 56 = Minute 56
• Z = Zulu time (UTC/military time)

This report was issued on the 12th at 1856 UTC (6:56 PM UTC). This matters because conditions change, and you want the most recent weather.

Section 3: Wind

Format: DDDSPGGGKT

Example: 09014G25KT

• 090 = Wind from 090° (due east)
• 14 = 14 knots sustained speed
• G25 = Gusts to 25 knots
• KT = Knots (nautical miles per hour)

For Part 107: Wind from 090° blowing at 14 knots with gusts to 25 knots. This is important—if your drone's maximum wind rating is 20 knots, gusts to 25 knots exceed that. You should not fly.

Wind Abbreviations:

• VRB = Variable (light wind changing direction)
• KT = Knots (typical in US)
• MPS = Meters per second (used internationally)

If wind is calm, you'll see "00000KT".

Section 4: Visibility

Format: Visibility in statute miles

Examples:

• 10SM = 10 statute miles
• 5SM = 5 statute miles
• 1/2SM = 0.5 statute miles (or written "1/2SM")
• 1SM = 1 statute mile

Critical for Part 107: Your minimum ground visibility is 3 statute miles. If a METAR shows less than 3SM, you cannot legally operate. Examples:

• 2SM visibility = CANNOT FLY (below minimums)
• 3SM visibility = CAN FLY (meets minimums, barely)
• 5SM visibility = CAN FLY (safely above minimums)

Sometimes visibility is reported as a fraction of a mile: "1/4SM" = 0.25 statute miles. This indicates very poor visibility (fog, heavy rain), and you definitely cannot fly.

Section 5: Weather Phenomena

This section describes what's happening in the sky. It's only included if there's something to report. If this section is absent, conditions are clear.

Format: Intensity + Descriptor + Phenomenon

Examples:

• -RA = Light rain
• RA = Moderate rain
• +RA = Heavy rain
• SN = Snow
• TSRA = Thunderstorm with rain
• BLSN = Blowing snow

For Part 107: Rain, snow, and thunderstorms make drone operations unsafe. If you see precipitation in the weather phenomena section, you should not fly. Drones are not waterproof, and thunderstorms create dangerous electrical hazards.

Section 6: Cloud Coverage

Format: Coverage + Altitude (in hundreds of feet)

Cloud Coverage Codes:

• SKC = Sky clear (no clouds)
• CLR = Clear (no clouds visible below 10,000 feet)
• FEW = 1-2/8 coverage
• SCT = 3-4/8 coverage (scattered)
• BKN = 5-7/8 coverage (broken)
• OVC = 8/8 coverage (overcast)

Examples:

• FEW250 = Few clouds at 25,000 feet AGL
• BKN050 = Broken clouds at 5,000 feet AGL
• OVC010 = Overcast at 1,000 feet AGL (clouds covering the sky at 1,000 feet)

Critical Part 107 Rule: Cloud Clearance Requirements

• You must maintain 500 feet vertical clearance below clouds
• You must maintain 2,000 feet horizontal clearance from clouds

Example Decision-Making:

METAR shows: "BKN050 OVC075"

• Broken clouds at 5,000 feet, overcast at 7,500 feet
• You can fly at 400 feet AGL (500 feet below 5,000-foot clouds = minimum safe altitude is 4,500 feet, but you're only at 400 feet... wait, that doesn't make sense)

Actually, let me clarify: "500 feet vertical clearance" means you stay 500 feet BELOW the clouds. So if clouds are at 5,000 feet AGL, you must stay at or below 4,500 feet. Since Part 107 limits you to 400 feet, you're fine. You're well below the cloud base.

But if clouds are at 800 feet AGL (very low ceiling):

• You need 500 feet clearance below clouds
• 500 feet below 800-foot clouds = 300 feet AGL minimum altitude
• Since you can operate up to 400 feet AGL, and the minimum safe altitude is only 300 feet, you can operate

However, if clouds are at 300 feet AGL (very rare but possible in fog):

• 500 feet clearance below 300-foot clouds = negative number (impossible)
• You cannot legally operate because there's no safe altitude that gives you 500-foot clearance below the clouds AND stays at 400 feet or below

This is why cloud clearance is critical.

Section 7: Temperature and Dewpoint

Format: TT/DD (in Celsius)

Example: 23/14

• 23 = Temperature 23°C (73°F)
• 14 = Dewpoint 14°C (57°F)

What's Dewpoint? The temperature at which air becomes saturated and moisture condenses into clouds or fog. If temperature and dewpoint are close (within 5°C), fog or low clouds are likely.

Example: Temperature 10°C, Dewpoint 9°C = Very close, fog likely

For Part 107: Fog lowers visibility drastically. If you see temperature and dewpoint close together, expect low visibility and possibly fog. Check the visibility number—if it's below 3 statute miles, you cannot fly.

Section 8: Altimeter Setting

Format: AXXXX (in hundredths of an inch of mercury)

Example: A2990

• A2990 = Altimeter reading 29.90 inches of mercury
• Normal atmospheric pressure at sea level = 29.92 inches

For Part 107: This affects how aircraft altimeters read. If you're flying near an airport where manned aircraft operate, this setting is important for understanding actual flight levels. For drone operations, it's less critical, but it's part of the full METAR format.

Decoding Real METAR Examples

Let's practice decoding three realistic METARs and make Part 107 flight decisions.

Example 1: Clear Day

KJFK 121851Z 31008KT 10SM FEW250 22/14 A3012 RMK AO2

Decoding:

• Station: JFK (New York)
• Time: Day 12, 1851 UTC
• Wind: From 310° at 8 knots (light wind)
• Visibility: 10 statute miles (excellent)
• Weather: None (clear skies)
• Clouds: Few at 25,000 feet (essentially clear)
• Temperature: 22°C (72°F), Dewpoint: 14°C (57°F)
• Altimeter: 30.12 (normal)

Flight Decision: YES, CAN FLY

• Visibility 10SM ✓ (meets 3SM minimum)
• Wind 8 knots ✓ (manageable for most drones)
• Clouds 25,000 feet ✓ (plenty of clearance)
• No precipitation ✓
• All conditions favorable for Part 107 operations

Example 2: Marginal Conditions

KSFO 121856Z 27018G28KT 4SM BR OVC040 18/17 A3001 RMK AO2

Decoding:

• Station: SFO (San Francisco)
• Time: Day 12, 1856 UTC
• Wind: From 270° (west) at 18 knots, gusts to 28 knots (STRONG)
• Visibility: 4 statute miles (marginal)
• Weather: BR (mist/fog)
• Clouds: Overcast at 4,000 feet
• Temperature: 18°C (64°F), Dewpoint: 17°C (63°F) (very close—fog likely)
• Altimeter: 30.01

Flight Decision: NO, CANNOT FLY

• Wind gusts to 28 knots: Exceeds most drone ratings
• Visibility 4SM: Above the 3SM minimum, BUT...
• Mist/fog (BR): Dangerous for visual line of sight
• Temperature/Dewpoint nearly equal: Fog conditions
• Multiple factors make this unsafe

Example 3: Poor Conditions

KDFW 121853Z 18022G35KT 2SM +TSRA BKN025 CB 20/18 A2985 RMK AO2 PK WND 18035/1828

Decoding:

• Station: DFW (Dallas-Fort Worth)
• Time: Day 12, 1853 UTC
• Wind: From 180° (south) at 22 knots, gusts to 35 knots (VERY STRONG)
• Visibility: 2 statute miles (BELOW minimum)
• Weather: +TSRA (heavy thunderstorm with rain) and CB (cumulonimbus cloud)
• Clouds: Broken at 2,500 feet
• Temperature: 20°C (68°F), Dewpoint: 18°C (64°F)
• Altimeter: 29.85

Flight Decision: ABSOLUTELY NO—DO NOT FLY

• Visibility 2SM ✗ (below 3SM minimum—ILLEGAL)
• Wind gusts 35 knots ✗ (dangerous for any small drone)
• Thunderstorm ✗ (electrical hazard, severe weather)
• Heavy rain ✗ (drones not waterproof, will be damaged)
• Multiple factors make flight illegal and extremely unsafe

The Part 107 Flight Decision Flowchart

Use this logic to evaluate METARs for Part 107 compliance:

Step 1: Check Visibility
Is visibility ≥ 3 statute miles?
NO → Cannot fly
YES → Continue

Step 2: Check Wind
Are sustained winds and gusts within your drone's rating?
NO → Cannot fly
YES → Continue

Step 3: Check Precipitation
Any RA (rain), SN (snow), TSRA (thunderstorm)?
YES → Cannot fly (drones not weatherproof)
NO → Continue

Step 4: Check Cloud Clearance
Can you operate at 400 feet AGL and maintain 500 feet below clouds?
NO → Cannot fly
YES → Continue

Step 5: Check Temperature/Dewpoint
Within 5°C of each other (fog likely)?
YES → Check visibility again (may need to go back to Step 1)
NO → Continue

All checks passed?
YES → Safe to fly (weather-wise)

METAR Practice Tips for the Exam

The exam won't ask you to decode an entire METAR word-for-word. Instead, questions will ask: "Given this METAR, can you fly?" or "What is the cloud ceiling?" Your job is to extract relevant information and make a judgment.

Practice Strategy:

• Visit aviation weather sites (AVWX, Aviation Weather Center) and decode 5 random METARs daily
• Focus on the elements you'll actually use: visibility, wind, precipitation, cloud coverage
• For each METAR, decide: Can I fly under Part 107?
• Practice with real METARs from various regions (coastal fog, mountain winds, desert clear skies, tropical thunderstorms)

Common METAR Exam Questions

Type 1: Visibility Decision
"A METAR shows 2SM visibility. Can you conduct Part 107 operations?"
Answer: No, minimum required is 3SM.

Type 2: Wind Decision
"Wind is from 180° at 15 knots, gusting to 22 knots. Your drone's maximum wind rating is 20 knots. Can you fly?"
Answer: No, gusts exceed the maximum.

Type 3: Cloud Clearance
"METAR shows OVC060. Can you maintain required cloud clearance at your planned altitude of 400 feet AGL?"
Answer: Yes, 6000-foot ceiling provides plenty of clearance (you need 500 feet below, so minimum safe altitude is 5,500 feet, but you're at 400 feet).

Type 4: Integrated Decision
"Given this METAR [full report], should you conduct your scheduled flight?"
You must evaluate all factors: visibility, wind, precipitation, clouds, temperature. The answer requires synthesizing all elements.

Mastering METAR for Part 107 Success

METAR is the language of aviation weather. Mastering it takes practice, not intelligence. Most pilots find that after decoding 10-20 real METARs, the format becomes intuitive. You start recognizing patterns: "BR and high temperature-dewpoint spread = fog," "TSRA = definitely no fly," "10SM and FEW clouds = great conditions."

The Part 107 exam will include 3-4 METAR interpretation questions. If you practice with real METARs from aviation weather sites and use the decision flowchart above, you'll answer these correctly and understand why each answer is right.

For comprehensive METAR practice with interactive decoding tools, quizzes, and scenario-based training, Flycensed includes an interactive METAR tool with 100+ challenges. This hands-on practice is proven to build expertise faster than reading alone.

Next time you see a METAR, you'll know exactly what it means and whether it's safe to fly. That knowledge keeps you and others safe in the National Airspace System.