Linking a weather station to a PC
Introduction
Although the modern weather station console can display a varied set of readings, it is difficult to overstate the additional benefits from linking your weather station to a PC and experiencing the resulting power and flexibility in using the stored weather data. For anyone with access to a PC, a data logging/software package has to be the number one accessory for your Vantage Vue or Pro 2 station. The impressive graphics plus comprehensive data storage and analytical features genuinely do add a new dimension to the power, usefulness and enjoyment of the station.
Davis Logger & Software Topics
Handling weather data on PCs & websites is covered extensively on this site - here are some links to related PC and website topics (current page is shown unlinked):
- Overview of loggers & software;
- Advice on PC linking
- Introduction to live weather websites
- Advice on weather websites
- Details of the Weatherlink product
- Summary of compatible software
- Various advanced topics
Linking a Davis station to a computer is a straightforward process that requires the Davis Weatherlink option; the contents of this package are described in more detail in the Weatherlink page of our Buying Guide so we'll restate only a few details here. Weatherlink consists of two main parts: a data logging module and a comprehensive software program. The data logger attaches to a special connector on the weather station console and its output connects to a standard RS232 serial port on a computer (or to a USB port with a special adapter). The logger's main function is to act as an always-on intermediate data store between console and computer that can, for example, store up to several weeks worth of data while the linked computer may be switched off. (Indeed in some AWS applications such as monitoring weather conditions in an isolated field site, the logger may be permanently disconnected except when a laptop may be connected briefly to download the most recent accumulated weather readings.)
NB This page is written taking the Davis Weatherlink software as an example to illustrate what PC-linking makes possible, but see also the short section at the foot of this page on Weatherlink vs other software packages.
The Davis Weatherlink program possesses a large number of features, which overall provide six main capabilities:
- Maintaining a permanent and detailed record of all weather data;
- Displaying current weather conditions in an impressive graphical presentation;
- Reviewing past weather in graphical form;
- Generating monthly and yearly statistical reports;
- Running a live weather reporting website;
- Providing a feed of weather data for other programs;
Each of these software capabilities is discussed further
below. Linking the weather station to a PC brings one other key
benefit in that all the technologies available in modern PCs and
networks for moving data around, potentially over long
distances, can be applied to the logged weather data. While the
simple standard station + PC installation will be perfectly
adequate for many users, those interested in a more advanced
configuration may wish to read our separate summary review of
additional data handling
options. Some additional information on operation of the
data logger will be found in the
Advanced Topics area
Note For the purposes of this website we've assumed that the linked computer is a standard Windows PC since this is by far the commonest situation and hence we use 'PC' as a generic term to refer to all types of computer. But stations can often be linked to other computer types, eg PCs running Linux or to Apple Macs, though at present the choice and capabilities of the available programs are often limited compared to the equivalent Windows software. For the present at least, it is nearly always better to link to a Windows PC if at all possible. Even a relatively old - perhaps retired - PC with a suggested minimum specification of 200MHz Pentium and 256MB RAM will often suffice.
Main Software features
Permanent weather record
A backstage feature, but a crucially important one: The Weatherlink software maintains a permanent, detailed, hard-disk archive of all weather data logged by Weatherlink since the system was first switched on, organised into separate monthly files for ease of backup and scaling. This archival database provides the data for all retrospective analyses and graphs and, over time, becomes a vital and immensely detailed library of all your local weather records. Any day's data - potentially years after the event - can be called up from the database and reviewed in detail.
Current weather display
The
Bulletin is Weatherlink's mode for providing a graphical display
of current weather conditions and is probably the most
well-known 'face' of the Weatherlink software. (Click thumbnail
at right to see the image full-size.) Latest readings from all
of the standard sensors, including solar and UV sensors if
fitted but omitted if not, are shown graphically to give a
snapshot of the latest weather conditions. The display also
includes various additional readouts including:
- Derived readings such as dew point and wind chill;
- Rainfall for multiple periods, including rainfall rate;
- A 6-hour trend graph for barometric pressure;
- A text forecast for the coming hours;
Review of past weather
All
of the weather data in the archive database is available for
detailed inspection, either record by record in the text-based
Browse mode or, as shown here, with the aid of the powerful Plot
mode. Any combination of the logged data values can be shown
plotted together over time-spans of hours, weeks, months etc.
Here we see an excerpt (title, key etc are normally visible)
showing maximum wind speed (left axis - mph - red); rainfall
(right axis - inches - blue bars) and pressure pattern (black)
for the month of March 2004 at our base.
Monthly and yearly statistical reports
A
range of periodic (eg monthly and yearly) text-based reports and
summaries can be created, with appropriate statistical analyses.
This reduced-size extract shows day-by-day temperature, rainfall
and wind data for the first 10 days of March 2004. Highs and low
values for each parameter are shown, where relevant, along with
times of occurrence. Various related indices such as the
'growing degree days' value used in agriculture may readily be
calculated also.
Live weather reporting website
Built into the Weatherlink software are all the features needed for running your own, automatically-updating, weather reporting website on the Internet, which can be viewed by anyone around the world. But don't overlook the fact that webpages are just as effective for distributing current weather data around a local area network and, for example, allowing a number of different people in the same building to view the latest weather data.
Setting up the website is straightforward for anyone with a modest familiarity with Windows software. You can choose from a range of pre-designed web page layouts, or design your own layout and include just those weather readings and graphs you wish. Read more about setting up a Weatherlink website.
Data source for other programs
As you can see, the Weatherlink software provides a great many features to analyse and to present the weather data. But with such a wealth of detailed data available, sometimes users prefer to perform analyses in their own unique way or may have a specialist use for the data not covered by the standard software packages. For these applications, Weatherlink provides a menu option to export any contiguous dataset in a standard text format for input to eg a spreadsheet program such as Excel. Weatherlink can also be set to generate certain text-format data files automatically, which - with some further programming - can be used as a direct source of the latest weather data by other programs. See our Advanced Topics area for a more detailed discussion.
Other Weatherlink features
There are also a number of further Weatherlink features not included in the main list above. These include:
- The auto-updating Strip Charts mode, graphically showing current values and trends for multiple weather parameters;
- An auto-updating daily Summary text window, which keeps track of new highs and lows as each day develops;
- Virtually all settings of the weather station console may be controlled from the PC;
- The option of additional software modules for specialist tasks, eg in agricultural management and alarm messaging;
Weatherlink vs other software packages
We've obviously used the Weatherlink software as the example of weather station software here. There is also a thriving after-market in third-party programs compatible with the Davis stations that offer even more features - sample output from some of these programs can be seen on the data-handling introductory page. But the Weatherlink software is what's included free in the Weatherlink pack; it's therefore typically the software that most users first encounter and also one that many users are perfectly happy with. Other makes of station will have their own proprietary software, usually each with their own quirks, and cheap stations will generally have only cheap and limited software.