Digital barometers
A digital barometer does the job an analogue dial does, then adds the thing a dial cannot: memory. Instead of comparing the needle against a brass marker you set yesterday, you get a plotted pressure history over the last several hours or days, and usually a forecast symbol derived from it.
Every instrument here combines pressure measurement with temperature, and most add humidity and a forecast display. For mechanical dial instruments, see the full barometer range or the modern analogue barometers.
Why the graph matters more than the reading
Air pressure on its own tells you very little. A reading of 1005 millibars could mean improving or deteriorating weather depending entirely on what it was three hours ago. Pressure forecasting is about rate of change and direction, not absolute value.
This is exactly what a digital barometer is better at. A pressure history bar graph shows the last several hours at a glance, so a steep fall is immediately visible as a shape rather than something you have to remember. A fall of three millibars or more in three hours indicates a system moving in and usually wind with it. A slow steady rise over a day or two indicates settling conditions. A flat trace means tomorrow will probably look like today.
The forecast icon most of these instruments display is generated from that trend by a simple algorithm. It is a reasonable guide over roughly the next twelve hours, and it is measuring your actual location rather than a regional average — which is the real advantage over a phone app. It is not a substitute for a proper forecast when weather is changing quickly.
The range
The Explore Scientific WSH4008 is the most affordable route into digital pressure measurement, combining a forecast station and barometer with humidity monitoring in a compact display.
The TFA HORIZON 35.1155 is a well-made forecast station and barometer from a manufacturer with a long history in pressure instruments, and it suits anyone who wants clear presentation over a long feature list.
The Technoline WS 9050 is the one to look at if you expect to grow the system, because it is expandable with additional wireless sensors — useful if you later want to monitor a greenhouse, garage or second room from the same display. The Technoline WS 9040 is the most complete instrument here, pairing the forecast station and barometer with a fuller display, and it is a consistent best seller.
Setting it up
Two things are worth doing on the first day. Set your altitude, if the instrument allows it, so pressure is corrected to sea level and comparable with published readings — otherwise a station a hundred metres up will read consistently low and look broken when it is not. Then leave it alone for a couple of days, because the pressure history graph and the forecast function both need data before they mean anything.
Position matters less than with a temperature instrument, because air pressure is effectively the same throughout your house. Put the display where you will actually look at it. Do keep it away from a draughty doorway or an open window, since sudden airflow can cause brief false readings on sensitive sensors.
Digital or analogue
Choose digital if you want the pressure trend shown for you, a forecast indication, and recorded highs and lows. Choose analogue if you want an instrument that will still be working in thirty years, needs no batteries and looks like furniture rather than electronics.
Plenty of customers own both, and there is a reason for that. The digital instrument is the one you check; the analogue one is the one you keep. For mechanical instruments see traditional wooden barometers, modern barometers and outdoor barometers, or the analogue weather station range for combined dial panels.
Related ranges
If you want pressure as part of a wider setup measuring rainfall and wind, see home weather stations and complete home weather stations. For pressure in a pocket instrument, the Kestrel range includes handheld meters that measure barometric pressure alongside wind and temperature. For clocks that include a barometer and forecast, see weather clocks.