How to read a TAF
A TAF (Terminal Aerodrome Forecast) is the airport's own forecast — what a METAR observes, a TAF predicts. It covers roughly five statute miles around the field for the next 24–30 hours, and it's written in the same compact code. Read it as a timeline, not a sentence: a base forecast, then a series of change groups that amend it.
TAF KMCO 251730ZStation & issue timeThe airport the forecast is FOR and when it was issued: day-of-month + HHMM Zulu. TAFs are normally issued four times a day.
2518/2624Validity periodFrom day 25 at 18Z through day 26 at 24Z. Everything that follows applies inside this window — most US TAFs cover 24 or 30 hours.
14008KT P6SM SCT035Base forecastThe starting conditions: wind 140° at 8 kt, visibility better than 6 statute miles (P6SM), scattered clouds at 3,500 ft. This holds until a change group says otherwise.
FM252100FM — a clean breakFrom day 25 at 2100Z, the forecast is REPLACED by what follows. FM lines are the TAF's backbone: read each one as a new weather chapter.
BECMG 2600/2602BECMG — a gradual shiftConditions transition to the new values over the window (here 00Z–02Z on the 26th). After the window ends, the new conditions apply.
TEMPO 2519/2522 3SM TSRATEMPO — on and offTemporary fluctuations lasting under an hour at a time within the window — here, periods of 3 SM in thunderstorms and rain. The base forecast still applies between them.
PROB30 2606/2609 1SM BRPROB — a percentage betA 30% (or 40%) chance of the stated conditions in that window. PROB30 fog at your ETA is exactly the kind of line worth planning an alternate around.
TAF vs METAR — which do you trust?
Both. The METAR tells you what the airport is doing right now; the TAF tells you what the forecaster expects it to do at your ETA. When they disagree, the METAR wins for the present — and a string of METARs trending away from the TAF is your cue that the forecast is busting. Only ~700 US airports get their own TAF, so at smaller fields you'll plan off the nearest TAF airport and watch the local METAR (each airport page names the station it uses).
Reading it for a go / no-go
- Find the change group covering your departure and arrival times first — not the base line.
- TEMPO conditions are real conditions: brief, but you can arrive during one.
- PROB30/PROB40 groups near your ETA deserve an alternate, fuel, or a later launch.
- Compare the forecast ceiling, visibility, wind and gusts against your personal minimums — not just the legal ones.
Want the decoding done for you? Paste any TAF into the free METAR & TAF decoder or open any airport page — the current TAF is decoded under the live conditions.
Get the forecast pushed to you
The Telegram bot watches your airport's reports and — with Premium — warns you when the TAF is expected to exceed one of your own limits. Free to start.
⚠️ Educational reference — not for operational use. Always get an official briefing and current reports from FAA-approved sources before flight.