About Cumulus

Cumulus is free software for retrieving, storing and displaying data from an electronic Automatic Weather Station (AWS).

Cumulus will store full weather records, along with daily and all-time records, and graphical data. Cumulus can upload its data to a web server and comes packaged with template web pages for this purpose. Cumulus also supports automatic uploads to Weather Underground and CWOP/APRS.

A variety of example screen shots are available.

The current version is 1.8.8 (December 1, 2009)

Full product details are available on the official Cumulus webpage including details on how to download


Supported Devices

  • Davis Vantage Pro and Vantage Pro2 weather stations
  • Oregon Scientific WMR-928 and WM-918 weather stations (and related models)
  • Fine Offset stations such as the WH1081
  • La Crosse WS-2300 range


There is a full list of Supported Devices


Warning: If your weather station is a La Crosse and it is connected using a serial/USB adapter, then you will probably have problems using it with Cumulus, in that you will get erroneous data from time to time. These weather stations are known to have problems with serial/USB adapters, and for some reason Cumulus seems to suffer more than other software. There doesn’t seem to be anything I can do about this. For this reason, I am sorry to say that I cannot support the use of Cumulus in this way.

Supported Operating Systems

Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Home Server, and Windows Server 2008. It may also work on Windows 2000, but this is not supported. You will probably not be able to get it to work on Windows 2000 with a Fine Offset station.


Key Features

  • Free for personal and non-profit use, but a donation would be appreciated if you continue to use Cumulus after trying it
  • Runs on Windows XP, Windows Vista, and Windows 7
  • Supports Davis Vantage Pro and Pro2; Oregon Scientific WM918, WMR-918, WMR-928, WMR-968 weather stations; EasyWeather stations (MyDEL, Nevada, Watson, Fine Offset, WH1080, WH1081, W8681, FWS-20 etc); La Crosse WS-2300 and other models in the WS23xx range.
  • Easy to use, clean display
  • Choice of meteorological day - midnight to midnight or 0900 to 0900
  • Numeric and graphical display of data
  • Real time web display of wind speed and direction
  • Automatic upload of data to web sites, Weather Underground, CWOP/APRS, PSW Weather/WeatherForYou/HAMweather, Twitter
  • Ready-made web pages supplied, or build your own using web tags
  • Configurable alarms for various conditions
  • Sunrise, sunset and moon phase display
  • Displays historical data for any given month or year
  • Graphical display of historical data for any time period
  • Generation of xAP home automation weather reports
  • Comprehensive help file included
  • Free support available in the support forum

Web pages

Web pages included:

  • Current Conditions
  • Gauges (with real time wind display)
  • Current Meteorological Day: Maxima and Minima
  • Previous Meteorological Day: Maxima and Minima
  • All Time Records: Maxima and Minima
  • Trend Graphs

The standard menu navigation allows for inclusion of both a forum link and a link to a webcam. Custom web pages can be achieved through the use of web tags added to any HTML/CSS layout. Support


Help and Support

Cumulus includes a comprehensive Help File.

There is also a FAQ (work in progress) and a Wiki

Further help, support, and discussion is available on our Forum. You will need to register to be able to post to the forum. Please submit bug reports and requests for enhancements there.


Donations & Sandaysoft

a note from the developer...

Sandaysoft is the home of Cumulus, software to help you make the most of your weather station. Located on the island of Sanday, in Orkney, off the north coast of Scotland in the UK. Cumulus is donationware. If you like the software and find it useful, please make a contribution towards the continuing development of Cumulus.

I rely on your donations to allow me to buy the software that I need to continue improving Cumulus. 100% of any donation received goes towards software development, either towards the cost of new development tools or the cost of hosting this site. We don’t make a profit from Sandaysoft - I have a full-time job and Sandaysoft is what we do in our spare time.

Donate via PayPal