Aviation weather is written in a code that was designed to survive a teleprinter, and it still looks like one: five-figure groups, no punctuation, and a meaning that changes with the country the report came from. The same field is metres in Warsaw and statute miles in Denver; the same pressure is Q1013 on one side of the Atlantic and A2992 on the other. A forecast reuses the observation's grammar almost unchanged and then hangs a validity period and a set of change groups off it. All of it is written down — the Federal Meteorological Handbook No. 1 and NWS Instruction 10-813 cover the American forms, the Met Office publishes the international ones, and the FAA sets out how a runway number and a wind direction relate — so nothing here has any business guessing. The tools read what the handbooks define and list what they do not, rather than quietly dropping the parts they cannot place.
Tools in this category
METAR Decoder
Paste a raw METAR and read it in plain English: wind, visibility, weather, cloud, temperature and pressure, with anything it cannot place listed, not dropped.
TAF Decoder
Paste a raw TAF and read the forecast in plain English: the period it covers, and every FM, BECMG, TEMPO and PROB group broken out on its own.
Crosswind calculator
Split a wind into the part down the runway and the part across it, from the runway number, the wind direction and the speed.
Suggest a tool
Tell us what is missing and where its numbers should come from.
What should it convert, calculate or generate, and where would the authoritative numbers come from? A link to the standard or publication that defines them is the most useful thing you can send.
Opens your mail app with this page already filled in.
How these tools are built
Every tool in this category runs entirely in your browser: there is no upload, no account and no request to a server once the page has loaded. The numbers behind them are transcribed from the organisation that defines them — NIST for units, the W3C for web formats, the WHO for health measures — and each page names its source next to the formula. A tool whose reference values stop reproducing fails the build and does not ship, which is the whole reason the catalogue grows slowly.