# Chart builder

URL: https://pro-weather.com/docs/features/chart-builder

> An optional Build a chart tab where visitors pick up to six measurements from your archive, choose the colours and set any date range up to 400 days.

Every measurement tab draws a fixed chart with a fixed range switcher. The
**Build a chart** tab lets a visitor draw their own: any mix of up to six
measurements from your archive, in colours they pick, over any window up to
400 days. It is how someone answers a question the standard panels do not, such
as how soil temperature tracked air temperature through a frost, or whether a
pressure fall lined up with a rain burst.

It is off by default and is a Pro feature, because it needs the archive that
Pro keeps.

## Switching it on

Turn on **Chart builder** under **Panels → Tabs & sections**. It is a switch
rather than a checkbox because it is a bigger decision than showing another
panel: it opens your whole archive to be queried by anyone who visits, which is
worth deciding rather than inheriting.

## What a visitor can do

- Tick up to **six** measurements. Only measurements your station has reported
  within the last 400 days are offered, so a station without a solar sensor is
  never shown a solar series.
- Give each series its own colour. The starting colours match the fixed
  charts, and a visitor's own picks apply only to their chart.
- Set a **from** and **to** time, up to 400 days apart. The inputs are bounded
  by your oldest archived reading, and the tab opens on the last seven days.

Series are grouped the way the archive is: temperature (air, dew point, heat
index, wind chill, wet bulb, indoor, daily high and low), humidity (outdoor and
indoor), wind (average, gust and wind run), pressure (sea level and station),
rain (amount, rate and storm total), sun (solar radiation, UV and
evapotranspiration), air quality (PM1, PM2.5 and PM10), lightning, snow
(depth and 24-hour snowfall), and every soil, leaf, room and probe channel your
hardware supplies.

Measurements that share a unit share an axis, so two temperatures are drawn to
the same scale and a temperature next to a pressure gets a second axis.

## How the data is summarised

A short window is drawn from raw readings. Longer windows are bucketed so a
chart never carries more points than a screen can show: hourly up to eight
days, three-hourly to about a month, twelve-hourly to about three months, and
daily beyond that. Each series is summarised the way its measurement demands:
temperatures are averaged, gusts and rain rates take the bucket's maximum,
rainfall and wind run are summed.

Values follow your site's [unit system](https://pro-weather.com/docs/customizing/units-language), and
the times follow your station's time zone.

## Next steps

- [History, records & the almanac](https://pro-weather.com/docs/features/almanac-history): the fixed
  charts and when their ranges unlock
- [Tabs & panels](https://pro-weather.com/docs/customizing/panels)