History, records & the almanac
How your archive builds up, when longer chart ranges unlock, and what the almanac shows.
The longer your site runs, the more interesting it gets. Every reading your station produces is stored in your site's own archive — permanently — and that archive powers historic charts, all-time records and a full climate almanac.
How your archive builds
Pro Weather saves your station's readings on every refresh, about every 10 minutes, into a database you control through your site. Nothing is ever trimmed or rolled up away.
- On WeatherLink Pro/Pro+, your past data is also imported backwards in time, so charts and records can start out full.
- On the free WeatherLink Basic plan, history builds forward from the day you connect.
See WeatherLink plans & your data for the full picture.
Historic charts
Every detail tab (Temperature, Wind, Rain, Pressure and so on) has a range switcher: 24h, 7d, 30d, 90d and 1y. Longer ranges unlock as your archive grows, so a brand-new site starts with 24 hours and earns the rest:
| Range | Unlocks after roughly |
|---|---|
| 24h | right away |
| 7d | 1½ days of data |
| 30d | 8 days |
| 90d | a month |
| 1y | 3 months |
Longer ranges are summarised into wider steps (hourly for 7d, up to daily for 1y) so charts stay fast — but the high/low stats shown above each chart are computed from your raw readings, so a 2-second gust or a momentary temperature spike is never flattened away.
Shareable ranges
The selected range is part of the page address (for example ?range=30d), so
you can link someone straight to a monthly view.
The almanac
The Almanac tab is your station's climate book. It appears automatically once your archive holds about a week of complete days, and grows richer from there:
- All-time records: hottest day, coldest night, wettest day, strongest gust, longest dry spell and the number of rain days.
- Monthly summary: a table per year with each month's average high, average low, total rain and strongest gust.
- Yearly records: once your archive spans more than one year.
- This day in history: what this date looked like in previous years, once you have over a year of data.
- "New record today!": when today beats an all-time record — hottest day, coldest night, wettest day or strongest gust — the almanac celebrates it with a banner.
A couple of definitions the almanac uses: a rain day is any day with at least 0.2 mm, and days with only partial data (like your very first day) don't count toward records, so a half-measured day can't set a false record.
The wind rose
The Wind tab can include a wind rose: a compass-shaped chart showing which directions your wind has blown from over the last 30 days, coloured by wind strength. Choose between an 8-point or finer 16-point rose under Settings → Weather features, where you can also toggle the rose and the live wind-direction compass. Like everything historic, it fills in over time — a new site shows "Collecting wind data" until enough samples exist.
Plan notes
Historic charts, the almanac and the wind rose are part of the Pro plan and your free trial. Your archive itself always keeps collecting while your site is active, and you can export it as CSV at any time.