A weather station project has a clean arc: turn a few sensors into readings, readings into a stored record, and that record into a dashboard the class can read at a glance. The work splits into five stages, pick your sensors, site them well, log the data, graph it, and add a handful of forecast rules, and each stage teaches something on its own. This guide walks the full path so a teacher or a keen student can plan a build that survives real weather.

Start with what you want to measure

The temptation is to buy a big sensor kit first and work out the point later. Do it the other way round. Decide what questions the station should answer, and the hardware follows. Temperature and humidity are the natural first pair: cheap to read, easy to graph, and immediately relatable. Air pressure is the quiet hero, it does little on its own but unlocks basic forecasting once you track how it changes. Rainfall and wind are rewarding but mechanical, so treat them as stage two once the electronics side is stable.

For a first classroom build, aim for three measurements you can trust rather than seven you half-understand. A station that logs temperature, humidity and pressure reliably for a full month is a better project than one that reads everything for a day and then drifts.

Choosing your sensors

Most school stations lean on a small, well-documented set of parts. You do not need laboratory gear; you need sensors your controller can read and your students can wire without tears.

• Temperature and humidity — a combined digital sensor (the common DHT-style modules) gives both from one part and one data pin.
• Air pressure — a barometric sensor (BMP-style) adds pressure and often a second temperature reading for cross-checking.
• Light — a light-dependent resistor is a cheap way to log day length and cloud cover, and a gentle intro to analogue readings.
• Rainfall — a tipping-bucket gauge counts pulses; each tip is a fixed volume, so the software does the maths.
• Wind — an anemometer for speed and a vane for direction are the most mechanical parts and the most failure-prone outdoors.

The controller in the middle matters as much as the sensors. A board with clearly labelled pins, analogue and digital inputs, and a forgiving programming environment saves hours. The sheenbot∞ board we use in class covers the common sensor types and lets students move from a single reading to a timed logging loop without changing tools. Whatever you choose, buy one or two spare sensors from the start; the store order you place today is cheaper than the lesson you lose to a dead part next month.

Siting: the part students skip

A good sensor in a bad spot gives confident, wrong numbers. Placement is where a weather project becomes real science. The classic mistake is a temperature sensor bolted to a sunlit brick wall, which measures the wall, not the air.

• Put the temperature and humidity sensors in shade, with air moving freely around them. A slatted box, a home-made Stevenson screen, is the traditional fix.
• Mount them at roughly chest height, away from tar, concrete and air-conditioner exhausts that radiate stored heat.
• Keep the rain gauge in the open, clear of overhanging roofs and trees, with its rim level.
• Place wind sensors as high and clear as you safely can; buildings create swirls that make readings meaningless.
• Plan the power. With load shedding a fact of school life, a station that runs off a small battery or logs to local storage will outlast one that dies with every outage.

Logging and building the dashboard

Logging is simply reading the sensors on a timer and writing each reading down with a timestamp. Every fifteen or thirty minutes is plenty for weather, which changes slowly. Two honest options exist for storage: write to an SD card or onboard memory and collect it later, or send each reading over WiFi to a spreadsheet or a small web page. Local storage is more robust and teaches file handling; a networked feed is more exciting and teaches how data moves. Many classes do the first, then graduate to the second.

The dashboard is where numbers become insight. A column of figures tells you nothing; the same data as a line graph over time tells you the day cooled before the rain and warmed after. Start in a spreadsheet, students paste the log, chart temperature against time, and immediately see the pattern. A more ambitious group can build a simple web page that reads the live feed and draws the same graphs automatically. Keep the first dashboard boring and readable: clear axis labels, sensible units, one line per measurement.

Simple forecast rules

Forecasting sounds like the hard part; the schoolroom version is a few rules of thumb tied to your pressure log. The most useful signal is the trend, not the value: pressure falling steadily over a few hours often means unsettled or wet weather on the way, while a steady rise points to clearing and calm. Pair that with humidity climbing towards the evening and you can make a genuine call for the next morning.

Write the rules as plain if-then statements the students design themselves. If pressure has dropped by more than a set amount since this morning, flag rain as likely. They will be wrong sometimes, which is the point: comparing yesterday's prediction with today's sky is the whole lesson. As the Cape moves out of its wet winter into spring, a pressure log gives a class something concrete to argue about.

Extensions and takeaway

Once the core loop is solid, the fun extensions are cheap. Add an alert: a buzzer or LED that trips when a frost threshold is crossed, or a signal when rain is first detected. Compare your station against the official record from the South African Weather Service for the same day, and discuss why a school rooftop and an airport runway disagree. Enter the numbers in a class competition, or hand the finished station to next year's group as a running dataset.

Build small, site carefully, log honestly, and let the graph do the teaching. A weather station is one of the few projects that keeps giving data long after the marks are in. If you would like students to build one with guidance, our holiday workshops and weekly classes run projects in exactly this shape, and you can browse more build write-ups on the newsroom.

FAQ

What is the minimum kit for a first weather station?

A microcontroller board, a combined temperature-and-humidity sensor, a way to store or send the readings, and a means to graph them. Everything else, pressure, rain and wind, is an upgrade you add once that core loop runs unattended for a week.

How often should the station take a reading?

Every fifteen to thirty minutes suits weather, which changes slowly, and keeps the log small enough to graph easily. If you are chasing a fast event like a passing storm, drop to a reading every minute for that window, then return to the slower rhythm.