A weather journal is the cheapest instrument you will ever own. No batteries, no calibration, no app to update. Just a notebook, a pen, and the same few minutes each day spent looking properly at the sky instead of glancing at it on the way past.

Keep it up for a month and something shifts. You begin to notice that the wind backs round before rain arrives, that frost forms on clear still nights but rarely under cloud, that the first swifts turn up within a day or two of a particular warm southerly. None of that comes from a forecast. It comes from your own records, in your own handwriting.

Choose a notebook you will actually use

An A5 hardback with an elastic band is ideal, but a cheap exercise book does the job just as well. Lined pages suit lists; plain ones let you sketch cloud shapes, which is often quicker than describing them. Keep the pen with the book rather than hunting for one each morning, and give the book a permanent home: by the door, on the kitchen windowsill, wherever you will see it.

A plain text file or a simple spreadsheet works too, though paper has the edge for a daily habit. No notifications, no scrolling, and no temptation to reorganise the layout instead of writing anything down. Decide now and don't overthink it. A scruffy notebook with six weeks of entries beats a beautiful one you are afraid to spoil.

Set up the first few pages

Before you record anything, spend ten minutes on the front of the book.

Page one is your key. Write down the units and shorthand you plan to use — °C, hPa, oktas, N/E/S/W — so that a year from now you can still read your own entries. Anything you invent, define it here.

Page two is your site. Note where you observe from, roughly how high above the ground your thermometer sits, and what surrounds you: a south-facing wall, a large sycamore, the coast two miles east. This context matters later, when you compare June this year with June next.

Then start the entries. One page per week with a line per day is compact and easy to scan. One page per day leaves room for sketches and longer notes. Most people begin with a line a day and let the interesting days spill over.

Tue 4 Feb, 07:20 — 2°C. 8 oktas, stratus, drizzle since 06:00. Wind SW, light. 1012 hPa, falling. First crocuses out by the wall.

What to record each day

Keep the core list short enough to finish in two minutes. Six or seven fields is plenty at the start; you can add more once the habit holds.

  • Date and time. Aim for the same slot each day. Mixing 7am readings with 9pm ones makes temperatures hard to compare.
  • Temperature. Read from a shaded thermometer rather than a sunny wall, and note where it hangs.
  • Cloud cover. Estimate in oktas, or eighths of the sky. Clear is 0, overcast is 8. Guessing to the nearest eighth is fine — the day-to-day change is what matters.
  • Cloud type. One or two words is enough: cumulus, stratus, altocumulus, cirrus. If you are unsure, describe what you see — flat grey sheet, puffy tops, high wisps.
  • Wind. The direction it blows from, plus a rough strength. Still air, leaves rustling, branches moving: that scale is accurate enough to begin with.
  • Precipitation. Type, whether it started or stopped during the day, and a rough amount if you have a gauge.
  • Pressure. If you own a barometer, note the reading and whether it has risen or fallen since yesterday. The direction of travel often tells you more than the number.
  • Notes. First frost, thunder, fog, a rainbow, the first swallows. These are the lines you will enjoy rereading most.

Beyond the basics

Once the daily entry feels automatic, add whatever interests you: visibility, dew, snow depth, frost dates, the day the leaves open, moon phase, halos round the moon, persistent contrails. Two cautions. Never look directly at the sun, and observe thunderstorms and named storms from indoors — no journal entry is worth that risk.

On instruments

You do not need a weather station. A thermometer in a shaded spot and a basic rain gauge will carry you a long way; a barometer is a welcome addition rather than a requirement. How carefully you site and read a cheap instrument matters far more than what you spend on an expensive one.

Build a routine that survives a bad week

Habits stick when they are attached to something you already do. The kettle boiling, the dog going out, the last look at the garden before bed.

  • Same time, same place. Book and pen live together, in view.
  • Three minutes, no more. Time it once and you will stop treating it as a task.
  • Never miss twice. If a day slips, write it up from memory next morning and mark it as estimated.
  • Consistency beats precision. A rough entry every day is worth more than careful readings twice a month.

Read it back at the end of the month

Set aside ten minutes on the last day of the month and write a summary page: highest and lowest temperature, number of wet days, days with frost, the wind direction that turned up most often.

Then look for pairings. Frost and cloud cover. Rain and falling pressure. Wind direction and temperature. Your own entries will start suggesting questions, and answering them is the real pleasure of the whole exercise.

Comparing your notes with published figures from the Met Office or a nearby station can be interesting, but remember that a back garden sits in its own small climate. A month, or even a year, is your local weather rather than anything wider. That is quite enough to be getting on with.

Start tomorrow morning

Pick a time, put the notebook where you will see it, and write tomorrow's six lines before your tea goes cold. Do the same on Tuesday. The third day is where a weather journal tends to become a habit, and by the end of the first month you will have something no app can give you: a record of your own sky, kept by you.

Photo: World-fly / Pixabay