How to read a TAF for the Part 107 test

To read a TAF for Part 107, treat it as a timeline, not one long weather sentence. Decode the issue time and valid period, split the forecast at every FM, TEMPO, or probability group, and then determine which wind, visibility, weather, and sky conditions apply during the planned flight.

The current Remote Pilot Airman Certification Standards specifically includes terminal aerodrome forecasts under UA.III.A.K3. The test is checking whether you can use the forecast, not merely say what the letters TAF stand for.

This guide follows the current FAA format described in AIM paragraph 7-1-28 and 7-1-29. Review how to read a METAR first if wind, visibility, weather, or cloud codes are unfamiliar; TAFs reuse many of them.

What a TAF tells you

A Terminal Aerodrome Forecast is a concise forecast of expected meteorological conditions for the area around an airport. At most locations the forecast period is 24 hours; selected locations use 30-hour periods. Routine TAFs are scheduled four times daily for periods beginning at 0000Z, 0600Z, 1200Z, and 1800Z, with amendments when needed.

That definition gives you four limits to remember:

• A TAF is a forecast, so compare it with current observations.
• It applies to a terminal area, not every point in a wide drone route.
• All times are UTC, shown with Z for Zulu.
• An amended TAF can replace an earlier forecast when conditions or expectations change.

For an actual operation, use the current official forecast and assess the launch site directly. PilotWrittenPrep is independent practice material, not an FAA weather provider.

The basic TAF structure

The FAA summarizes a TAF in this order:

1. report type;
2. station identifier;
3. date and time of origin;
4. valid-period date and time; and
5. forecast meteorological conditions.

The forecast conditions are normally organized as wind, visibility, weather, sky condition, and optional wind-shear data. Unlike a METAR, a TAF can then add groups that change some or all of those conditions later.

Use this instructional example:

TAF KDEN 211720Z 2118/2218 17012KT P6SM SCT060

FM220200 21015G25KT 5SM -TSRA BKN030CB

TEMPO 2202/2206 2SM TSRA BKN015CB

FM220800 32010KT P6SM SCT040

We will decode the header, build the timeline, and then apply it to a Part 107 mission.

Decode the header first

TAF: report type

TAF identifies a routine forecast. TAF AMD identifies an amended forecast. A corrected or delayed product may be identified in its communications header; focus on the issue time and validity so you know which product you are using.

KDEN: station identifier

The four-letter ICAO identifier tells you which terminal the forecast covers. A nearby TAF can add useful context, but distance, terrain, elevation, shoreline effects, and convective weather can make your launch-site conditions different.

211720Z: issue time

The forecast was issued on the 21st at 1720 UTC. The pattern is two digits for the day, four for the time, then Z.

Do not confuse issue time with the time conditions begin. The next group gives the forecast's valid period.

2118/2218: valid period

This forecast is valid from the 21st at 1800Z until the 22nd at 1800Z. Each side contains a two-digit day and two-digit hour.

The end can fall on another UTC day. Draw a short line on scratch paper when a test scenario crosses midnight; it prevents the most common date error.

Decode the initial prevailing conditions

The initial line after the valid period is:

17012KT P6SM SCT060

It means:

• wind from 170° true at 12 knots;
• visibility greater than 6 statute miles; and
• scattered clouds at 6,000 feet AGL.

P6SM means “more than six statute miles,” not precisely six. SCT060 is not a ceiling because scattered is not broken, overcast, or vertical visibility. The cloud still matters to the Part 107 cloud-distance rule if the aircraft approaches it.

No significant weather group appears in this initial set. That does not mean every possible hazard is absent. It means significant weather is not included in that part of the coded forecast.

These conditions prevail from the start of the valid period until a later group changes them.

FM starts a new set of prevailing conditions

The next line is:

FM220200 21015G25KT 5SM -TSRA BKN030CB

FM220200 means from the 22nd at 0200Z. An FM group starts a new forecast period and presents a new set of prevailing conditions:

• wind from 210° at 15 knots, gusting to 25;
• visibility 5 statute miles;
• light thunderstorm rain; and
• broken cumulonimbus at 3,000 feet AGL.

An FM time uses day, hour, and minute: DDHHmm. That differs from the four-digit day/hour pairs used for a valid interval.

For Part 107, the critical clue is not only that visibility remains above 3 SM. The forecast now includes thunderstorms, stronger sustained wind, gusts, precipitation, and a lower broken layer. Those hazards can make an operation unacceptable even if one regulatory number remains technically above its minimum.

TEMPO adds temporary conditions

The next group is:

TEMPO 2202/2206 2SM TSRA BKN015CB

Between 0200Z and 0600Z on the 22nd, temporary conditions may include:

• visibility 2 statute miles;
• thunderstorm with rain; and
• broken cumulonimbus at 1,500 feet AGL.

The FAA describes TEMPO conditions as expected to last generally less than an hour at a time and occur during less than half of the stated period. Only changing elements need to appear. Elements not changed carry over from the prevailing group.

Here, no wind appears in the TEMPO group, so the prevailing 21015G25KT continues to apply. When a temporary episode ends, the prior FM conditions again prevail unless another change group begins.

For a mission anywhere in that interval, do not dismiss TEMPO as “not the main forecast.” It identifies a foreseeable period of substantially worse weather. In this example, 2 SM visibility is below the standard Part 107 minimum, and thunderstorms present independent reasons not to proceed.

A later FM resets the forecast again

The final line is:

FM220800 32010KT P6SM SCT040

From 0800Z on the 22nd, the new prevailing conditions are:

• wind from 320° at 10 knots;
• visibility greater than 6 statute miles; and
• scattered clouds at 4,000 feet AGL.

The thunderstorm and broken-ceiling groups are no longer part of the prevailing forecast after this FM change. A real go decision would still require current observations and a check for amendments or other hazards.

How PROB30 fits into the timeline

A TAF can use PROB30 to indicate a 30 percent probability of specified conditions during a stated period. For example:

PROB30 2204/2208 2SM TSRA BKN012CB

This indicates a 30 percent probability of 2 SM visibility, thunderstorm rain, and broken cumulonimbus at 1,200 feet during the interval.

Do not translate 30 percent into “safe.” Probability and severity are different questions. A lower-probability event can still demand a postponement when its consequence is severe and the mission has no strong mitigation.

The current AIM notes details of U.S. National Weather Service TAF practice, including limitations on when probability groups are used. For the test, read the exact group supplied and place it on the stated UTC interval.

Build the complete timeline

The example becomes:

• 21/1800Z to 22/0200Z: 170° at 12 knots, more than 6 SM, scattered 6,000.
• 22/0200Z to 22/0800Z: 210° at 15 gusting 25, 5 SM, light thunderstorm rain, broken cumulonimbus 3,000.
• Temporarily 22/0200Z to 22/0600Z: 2 SM, thunderstorm rain, broken cumulonimbus 1,500; the prevailing wind carries over.
• From 22/0800Z: 320° at 10 knots, more than 6 SM, scattered 4,000.

Writing four lines is faster than repeatedly scanning the code. It also reveals whether a planned operation overlaps a change.

Apply the TAF to a Part 107 mission

Suppose the launch is planned for 0130Z, with recovery at 0230Z. The initial conditions look favorable, but FM220200 begins during the mission. By planned recovery, the forecast includes gusts to 25 knots and thunderstorm rain, while TEMPO permits 2 SM visibility.

The correct analysis uses the whole mission window. A takeoff before 0200Z does not lock in the earlier forecast. Postpone or redesign the operation, then obtain updated official weather before flight.

Now suppose the launch is planned for 1000Z. The final FM group forecasts better visibility and no significant weather group, but you still need a recent METAR, site observations, aircraft limits, and a check for a TAF amendment. The TAF is evidence, not an automatic clearance.

Common Part 107 TAF mistakes

Reading issue time as the valid period

211720Z says when the product was issued. 2118/2218 says when it is valid. Keep the two jobs separate.

Ignoring the UTC date change

FM220200 means 0200Z on the 22nd. It does not mean 2202 local time or 0200 on the 21st.

Reading only the first line

The first prevailing conditions may end before your mission does. Scan every FM, TEMPO, and probability group before answering.

Forgetting carried conditions

A TEMPO group can list only the items that change. Unlisted prevailing elements continue. FM groups, by contrast, establish a new set of prevailing conditions.

Treating a TAF as an observation

Use a METAR for observed station conditions and a TAF for forecast change. Neither replaces an on-site assessment.

Looking only for the 3 SM visibility number

Legal minimums are necessary but not sufficient. Gusts, thunderstorms, precipitation, clouds, and aircraft limitations can make a flight unsafe before visibility reaches the regulatory floor. Review the exact Part 107 weather minimums.

A fast method for the test

Use this sequence under time pressure:

1. Circle the TAF valid period.
2. Write each FM, TEMPO, and PROB interval in UTC order.
3. Put the proposed flight time on that line.
4. Carry forward any unchanged TEMPO elements.
5. Check wind and gusts, visibility, weather, and ceiling/clouds.
6. Apply Part 107 rules and operational risk.

Then choose the answer that accounts for the relevant interval and the most consequential condition. Do not let one comfortable value distract you from a later thunderstorm or below-minimum visibility.

Practice this alongside the full Part 107 weather guide, try a few questions in the free demo, and use the Part 107 course for mixed, exam-style practice.

Official references used

• Remote Pilot — Small UAS Airman Certification Standards, FAA-S-ACS-10B
• Aeronautical Information Manual, Chapter 7
• Aviation Weather Handbook, FAA-H-8083-28B
• 14 CFR § 107.51

References checked July 21, 2026. Use current official weather products for every operation.