# Import your Cumulus / CumulusMX history

URL: https://pro-weather.com/docs/getting-started/import-cumulusmx

> Migrate years of archived weather data from Cumulus or CumulusMX into Pro Weather - the log files are read in your browser, nothing is uploaded, and re-running is always safe.

If you have been running [CumulusMX](https://cumulus.hosiene.co.uk/) (or the
original Cumulus 1), your station's whole history sits in the monthly log
files of its `data` folder. You can bring that history with you: imported
records show up in the historical charts, the records page and the almanac,
exactly as if Pro Weather had been collecting them all along.

## What you need

- A **PRO subscription or active trial** (history is a PRO feature).
- The **monthly log files** from your Cumulus `data` folder. They are named
  `202601log.txt` on CumulusMX 4, or `Jan26log.txt` (month abbreviation in
  your language) on older versions - both work, mixed is fine. On a typical
  install the folder is `CumulusMX/data`; copy it off the machine, e.g.
  `scp -r pi@raspberrypi:~/CumulusMX/data .`
- Ideally also your **Cumulus.ini** (one folder up, next to the CumulusMX
  executable). Include it in the selection and your unit settings are
  detected automatically; without it, pick the units by hand.
- Any browser on a desktop or laptop. The files are parsed **locally in your
  browser** - your logs are never uploaded, only the observation values
  travel to us.

## Run the import

1. Open **Dashboard → your site → Connection**.
2. Scroll to **Import history from Cumulus / CumulusMX** and select your
   monthly log files (you can simply select everything in the `data` folder -
   dayfile, extra-sensor and AirLink files are skipped automatically), plus
   `Cumulus.ini` if you have it.
3. Check the **log file units**. They must match what Cumulus was configured
   to use (Station settings → Units); with a `Cumulus.ini` in the selection
   this is filled in for you.
4. If your site has more than one station, choose which station the history
   belongs to. For hardware that uploads to us directly (the upload URL above
   the import card), that is your local (push) station.
5. Click **Import history** and leave the tab open. A multi-year archive
   takes a few minutes; you can watch the progress bar.

When it finishes, charts and records pick the new history up within a few
minutes (caches refresh on their own).

## Good to know

- **Safe to re-run.** Records that already exist - from live uploads or an
  earlier import - are never overwritten. If the import is interrupted, just
  run it again; already-imported records are skipped.
- **Every Cumulus unit configuration works.** °C or °F, m/s, mph, km/h or
  knots, mb, hPa, inHg or kPa, mm or inches - the importer converts from
  whatever your install logged.
- **Old log formats are fine.** Files written by Cumulus 1 and CumulusMX 3
  (separate date and time columns, semicolon separators, decimal commas) are
  detected and parsed alongside the current format.
- **What comes across:** temperature, humidity, dew point, heat index, wind
  chill, sea-level pressure, wind speed/gust/direction, rain and rain rate,
  solar radiation, UV, and indoor temperature and humidity.
- **Rainfall is rebuilt per interval.** Cumulus logs a running daily total;
  the importer turns that back into per-interval rainfall so rain charts and
  daily totals come out right.
- **Keep Cumulus running if you like.** Point its Wunderground uploader
  (Internet settings → Web/Upload) at your upload URL (see
  [Connect your own hardware](https://pro-weather.com/docs/getting-started/connect-hardware)) and
  live data continues from where the import ends.