# Editing stored data

URL: https://pro-weather.com/docs/data-editor

> Correct or remove a bad reading that is already in your history, and make the correction stick.

Three things can put a wrong number in your history, and each needs a different
fix:

| What happened | The fix |
| --- | --- |
| An impossible value (-40 °C in July, a 300 km/h gust) | Nothing to do. [Quality control](https://pro-weather.com/docs/calibration) never stores it. |
| A sensor that reads consistently high or low | [Calibration](https://pro-weather.com/docs/calibration), which corrects every future reading. |
| A one-off bad value already stored, or bad rows from an import | The **data editor**, described here. |

The data editor lives under **your site → Data** in the dashboard. It is
available on Pro, because that is where stored history lives.

## Finding the bad reading

Pick a station (if you have more than one), then a day. Times are your
station's local time, and the table shows every reading stored for that day.
A station reporting every minute produces more readings than fit in one view,
so you can narrow to a single hour.

If you spotted a spike on a chart but do not know its date, use the
**jump to the archive's extremes** links above the table. They take you
straight to the day holding your highest and lowest temperature, your strongest
gust and your wettest day, which is where a bad reading almost always shows up.

## Correcting a reading

Click a reading to open it. You can change:

temperature, humidity, wind speed, wind gust, wind direction, pressure,
rainfall, solar radiation and UV index.

Values are entered in your site's [unit system](https://pro-weather.com/docs/customizing/units-language).
**Clear a field to drop just that value** rather than the whole reading, which
is what you want when one sensor misbehaved and the rest of the row is fine.

Two things happen automatically when you save:

- **Dew point, heat index and wind chill are recalculated** from what you
  entered. They are derived values, so leaving them alone would leave the row
  disagreeing with itself.
- **The interval's stored high and low are cleared.** An archive record carries
  the highest and lowest value seen *within* that interval, and those describe
  the reading you just replaced. Your records and almanac read the interval high
  first, so leaving it would keep reporting the value you came here to fix.

A reading you have changed is marked **edited** in the table.

## Removing a reading

Open the reading and choose **Remove this reading**. Every value is emptied and
the timestamp stays behind as an empty slot.

That empty slot is deliberate. Pro Weather re-reads the last hour of your
station's archive on every update, and separately re-checks the last year for
days that look short of readings. A row that was simply deleted would be
re-imported within the hour, bringing the bad value back with it. The empty slot
tells us the reading is meant to be gone.

## Removing a range

For a sensor that produced hours or days of garbage, or an import that brought
in bad rows, use **Remove a range**. Give a start and an end, confirm, and every
reading between them is emptied. Wind directions in the same window are removed
too, so the wind rose stops showing the bad data.

A range removal covers up to three months at a time and **cannot be undone**, so
it asks you to confirm. Single readings can be undone.

## Undoing a change

**Recent changes**, at the bottom of the tab, lists everything you have changed
by hand. Anything except a range removal can be undone, which puts the original
values back exactly as they were.

Only the most recent change to a given reading can be undone. If you corrected
the same reading twice, undo the second change first.

## What a correction does not do

- **It does not change how your station reports.** If the same wrong value keeps
  arriving, the fix is [calibration](https://pro-weather.com/docs/calibration) or the sensor itself.
- **It stops that reading taking future updates.** An edited or removed reading
  is protected from being overwritten, which is what makes the correction
  permanent. The trade is that the reading also stops receiving any new
  measurements we might capture for it later.
- **It is not a way to invent history.** Every value you enter still has to be
  something a weather station could actually measure. A typed value outside
  those bounds is rejected, exactly as it would be if the station had sent it.

## Exports and your public site

Corrections apply everywhere at once: your charts, your records and almanac,
your [CSV export](https://pro-weather.com/docs/account-billing/account#export-your-data) and your
public site all read the
same archive. Changes show up on your site immediately rather than at the end of
a cache window.