When a personal weather site shows 68.4 °F next to the word Temperature, that figure is usually not a caption the operator typed this morning. It is a field: a slot in a page template that station software filled the last time it processed or uploaded the file. The historical TNET URL /aboutus.wxtags is the visitor’s explanation of that fact.
Operators looking up how a tag maps to a logger field want the web-tag vocabulary. Template authors who need a short list of common names want the mini glossary. This page stays with the person who simply sees a number and needs to know what kind of number it is.
Historical context
Cumulus sites were HTML (later PHP) files with markers where a human otherwise would have typed a reading. The program replaced each marker with a value and uploaded the result. Visitors never saw the marker. They saw a page that looked hand-written and was not. About sections explained the trick because the same site also showed graphs, banners, and “forecast” lines that were easy to mistake for a meteorologist’s product.
The dotted path /aboutus.wxtags sat with software and website-info credits: identity for humans, not a tag encyclopedia. No login form is offered here. The old CMS is not restored.
What you are looking at
A live field on a hobby weather page is a snapshot of an observation (or of a software-derived index) at processing time.
Three clocks are easy to confuse:
The weather’s clock. The thermometer had a temperature at a real moment. That is the observed event, subject to siting and calibration.
The software’s clock. Cumulus (or Weather Display, or another package) read the logger, formatted a number, and wrote it into the page or into a small data file the page reads. That write has its own time. If uploads stopped two hours ago, the page can still look “current.”
Your clock. The browser fetched the HTML just now. Fetch time is not observation time. A cached copy at an ISP or a forum hot-link can be older still.
A visitor who treats “the number I see at 3 p.m.” as “the air temperature at 3 p.m. at this garden” has collapsed those clocks. The honest reading is: this is the last published value this site knows how to show, in the units this site chose to show, produced by the program the software declaration names.
Why the page is not a typed caption
If the operator had typed 68.4 into the HTML, yesterday’s heat wave would still be on the page after a cold front. Template fields exist so the chrome (headings, colors, station name) stays still while the values move. That is the whole design.
Consequences that matter to a visitor:
- The number can be stale while the layout looks fresh. A new photograph in the header does not prove the temperature was uploaded in the last minute.
- A blank, a zero, or a nonsense string is a failed field, not necessarily a failed thermometer. Station software that does not recognize a marker may leave an error string. A script that treats a missing file as
0.0will draw a tropical night in a Minnesota January. - Units can be a second field. Some sites print the number from one slot and
°Cor°Ffrom another. A preference cookie may relabel the same packet. The cookie is not a new measurement. - Some “temperatures” are not thermometers. Wind chill, heat index, humidex, apparent temperature, and “feels like” are derived indices. They can be useful if labeled. They are not extra sensors.
Software forecast text or a Zambretti-style index on the same page is a scenario from the station program. It is not a National Weather Service forecast. For warnings, use NWS or the national service with authority at the site.
How to read a live field without being an operator
You do not need the tag language to use a PWS page carefully.
Find a time. A trustworthy station page prints when the values were last written—packet time, “updated at,” or a file stamp a status line exposes. If there is no time, treat the numbers as unlabeled.
Find a unit. 68.4 without Celsius or Fahrenheit is incomplete. Do not assume your country’s usual unit.
Find the software name. About, footer, or generator metadata should say Cumulus, Weather Display, or another package. That name tells you which public file family the site likely uses. It does not make the siting good.
Separate today from this minute. “Rain today” is a total since the station’s rollover, often not midnight in your time zone. “Rain rate” is a different quantity. Highs and lows are extremes with their own event times; they did not all happen “now.”
Do not promote a banner to a climate record. A 60-pixel PNG hot-linked on a forum is a derived picture of a packet. The climate memory, if it exists, is in the station’s logs.
Do not treat a pretty gauge as an official observation. A personal weather station is not an official aerodrome or NWS site unless the operator is part of a documented network and says so. The field is still an observation of that instrument.
What “live” does not mean
Hobby sites used “live” as a slogan. Scientifically it means “updated often relative to the hardware interval,” not “streaming from the thermistor into your browser.”
Cumulus’s optional realtime.txt is meant to be rebuilt frequently and uploaded for near-current readings; it is off by default and is not a historic archive (Cumulus Wiki: realtime.txt, last checked 13 August 2026). A processed HTML page that is uploaded every five minutes is live at a five-minute cadence. A daily climate table processed at rollover is live once per meteorological day. Both can use the same kind of field. The cadence is a publishing choice.
If the PC is off, the logger may still be recording locally while the website freezes. A visitor has no way to see the logger. The website field is only as live as the last successful publish.
Distinct from the operator pages
/tnetwebtags.php is the data-binding vocabulary: families of tags, clocks, extra sensors, and what to do when names change. /projects/tnetwebtags is an extra-file pattern for operators who needed more than the default site. /aboutus/wxtags is a glossary for people who write templates.
This About URL answers a smaller question: why the number moved, why it might have stopped, and how not to over-read it. You can use a station page well without ever typing a tag.
Modern relevance
JSON widgets and local APIs still fill slots. The visitor’s problem is unchanged: a number in a layout is a published field with a source, a unit, and a time, or it is decoration. TNET’s public vocabulary for observed, modelled, and derived information is how the service works. Freshness and source identity for records used in connection research are on data sources, quality controls, and methodology. The Cumulus hub lists the historical publishing pages around this one.
Sources
- Cumulus Wiki: Webtags (last checked 13 August 2026)
- Cumulus Wiki: realtime.txt (last checked 13 August 2026)
- NWS
- TNET, How the service works
- TNET, Data sources, quality controls and methodology