Why this domain matters
Weather questions test how weather affects a light aircraft and how to read a coded METAR or TAF. Learn the physical effects, then practice each report group.
How it works
Heat, high elevation, and humidity can make the air less dense. This raises density altitude and reduces available lift and thrust. Stable air resists vertical motion and often brings smooth flow, layered clouds, and poor visibility. Unstable air favors turbulence and cumulus clouds. The view can be clear between showers and poor inside them. Terrain and ground friction also change winds near the surface.
A METAR reports conditions observed at a station, usually hourly and sometimes more often. Check the observation time. Its groups include wind, visibility, weather, sky condition, temperature/dewpoint, and altimeter setting. A TAF forecasts wind, visibility, significant weather, and sky condition around an airport. Its valid-time and change groups show when conditions are expected. It does not use the METAR's observed temperature/dewpoint and altimeter groups. A small observed temperature/dewpoint spread signals possible fog or low visibility.
METAR and TAF practice
Decode the report before memorizing more weather terms.
Compare several reports, follow a forecast timeline, build a coded report, and make a drone-specific go, caution, or no-go decision.
Open the METAR and TAF labCalculate density altitudeUse this module for
- Weather theory, fronts, fog, stability, and thunderstorms
- Flashcards for report abbreviations and performance effects
- A short knowledge check before focused question practice
Key facts to memorize
| Concept | What to know |
|---|---|
| METAR | A METAR reports weather observed at a station, usually once an hour. Check the time it was observed. Its groups give wind, visibility, weather, sky, temperature/dewpoint, and altimeter setting. |
| TAF | A TAF predicts weather within 5 statute miles of the airport runway complex. Most span 24 hours; some span 30. Read its stated times. Its wind, visibility, weather, and sky groups can change through the period. It has no METAR temperature/dewpoint or altimeter groups. |
| Wind in a METAR | Reported as direction in degrees TRUE and speed in knots, e.g. 24015G25KT = from 240° at 15 kt gusting 25 kt. |
| Sky cover codes | FEW covers up to 2 eighths of the sky, SCT 3-4, BKN 5-7, and OVC all 8. The lowest BKN/OVC layer is a ceiling; VV reports one in a complete obscuration. SKC means clear. Automated CLR means no clouds detected below 12,000 ft. |
| Density altitude | Heat, high elevation, and humidity can make the air less dense. That raises density altitude and reduces available lift and thrust. Check how the aircraft performs in those conditions. |
| Temp/dewpoint spread | A small spread (close numbers) means high humidity and a higher chance of fog or low visibility. |
| Stable vs. unstable air | Stable air tends toward smooth flow, layered clouds, and poor visibility. Unstable air favors turbulence and clouds with vertical growth. Visibility may be good between showers and poor inside them. |
| Altimeter setting | Given in inches of mercury, e.g. A2992 = 29.92 inHg, the standard sea-level pressure. |
| ASOS/AWOS | Automated weather stations provide wind, visibility, sky condition, temperature/dewpoint, altimeter, and other local observations. |
| Weather charts | Surface analysis and prog charts help spot fronts, pressure systems, precipitation, and changing flight conditions. |
| Fronts and air masses | Cold fronts can bring gusty winds and thunderstorms; warm fronts often bring widespread clouds, precipitation, and reduced visibility. |
| Convective hazards | Thunderstorms, microbursts, tornadoes, hail, icing, and lightning are no-go hazards for small UAS. |
| Ceiling and visibility | Ceiling is the lowest BKN/OVC layer, or vertical visibility when an obscuration hides the sky. VV002 reports an indefinite ceiling of 200 ft. Separately check the Part 107 minimum of 3 SM flight visibility and the required distance from clouds. |
| Fog | A small temperature-dewpoint spread means moist air. Further cooling can produce fog, but the spread alone does not prove fog will form. Check wind, moisture, terrain, and the trend. |
Flashcards
Active recall beats re-reading. Flip each card, say the answer out loud, then check yourself. Prefer paper? See all five flashcard decks.
UAG III / Weather
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Quick self-check
A short drill on this module. You get the explanation the moment you answer.
0 / 6 answered
A METAR reports temperature 18°C and dewpoint 17°C. What does that spread suggest?
You plan to fly from a high-elevation site on a hot, humid afternoon. How does this affect performance?
Which product reports observed conditions at a station rather than a forecast?
A forecast calls for thunderstorms with possible microbursts. What is the safest Part 107 decision?
Which automated source can provide local wind, visibility, temperature/dewpoint, and altimeter information?
Which source should you use for a recorded or automated local airport weather broadcast before monitoring tower or CTAF?
Original practice material, not the actual FAA exam questions.
Review this module podcast
Listen to the Weather episode or read the full transcript.
Practice this topic
Work explained Weather questions before the full simulator.
Study material reviewed October 13, 2026 and sourced from the FAA (14 CFR Part 107, FAA UAS guidance, AC 90-48E, and current PSI test guidance). Flashcards and quiz items are original practice material, not the actual FAA exam questions. Educational, not legal advice. Verify current rules at faa.gov/uas before you fly.