Barometric pressure in Pretoria
Beneath its daily wave, pressure has barely moved. From here it rises until tomorrow morning.
Sea level reading, as of 17:00 local time. A barometer in Pretoria itself reads about 881 hPa.
The past week and the days ahead
The shaded part shows the days already gone. The thicker line is the forecast. The thin grey line is the average over a whole day, so you can see where pressure is heading under the daily up and down.
The week ahead
Each day at a glance: how far pressure moves, and the low and high it reaches.
Rises quickly, most of it in the evening.
29° / 15°low 1020 · high 1028 hPa
Rises first, then falls away in the afternoon.
25° / 11°low 1022 · high 1030 hPa
Falls steadily through the day.
27° / 13°low 1018 · high 1025 hPa
Rises quickly, most of it in the evening.
27° / 13°low 1019 · high 1028 hPa
Edges up slowly through the day.
22° / 13°low 1026 · high 1031 hPa
Falls steadily through the day.
22° / 11°low 1023 · high 1031 hPa
Falls quickly, most of it in the morning.
23° / 10°low 1019 · high 1027 hPa
Hour by hour
| Hour | Weather and temperature | Rain (mm) | Pressure (hPa) |
|---|---|---|---|
| 00:00 |  17° | 1022 | |
| 01:00 | 16° | 1022 | |
| 02:00 | 15° | 1022 | |
| 03:00 | 15° | 1022 | |
| 04:00 | 15° | 1022 | |
| 05:00 |  16° | 1023 | |
| 06:00 | 16° | 1023 | |
| 07:00 | 17° | 1024 | |
| 08:00 | 18° | 1024 | |
| 09:00 | 20° | 1025 | |
| 10:00 | 24° | 1024 | |
| 11:00 | 26° | 1024 | |
| 12:00 | 28° | 1023 | |
| 13:00 | 28° | 1022 | |
| 14:00 | 29° | 1021 | |
| 15:00 | 29° | 1020 | |
| 16:00 | 28° | 1020 | |
| 17:00 | 27° | 1020 | |
| 18:00 | 26° | 1021 | |
| 19:00 | 23° | 1022 | |
| 20:00 | 21° | 1023 | |
| 21:00 | 19° | 1025 | |
| 22:00 | 17° | 1026 | |
| 23:00 | 16° | 1028 |
Biggest change: Wednesday, up 6 hPa.
The high point comes tomorrow morning, near 1030 hPa; after that it falls.
In Pretoria pressure moves on a daily clock: about 6 hPa between its regular low and high, at much the same hours every day. That daily swing is most of the shape you see on the graph, so the change since yesterday tells you more here than the change over the past few hours.
Pretoria sits 1309 m above sea level, so a barometer in the city reads about 139 hPa lower than the sea-level figure. A home station set to the local reading should show about 881 hPa as of 17:00.
The hours already past are the model's record of each hour as it passed, anchored to real observations, though not a reading from an instrument in Pretoria.
Cities nearby
Open one to see its pressure, or search for your own city at the top of the page.
Curious what you are breathing? See the air quality in Pretoria today, on our sister site 
airindex.today.
Common questions
What is a normal barometric pressure?
Near 1013 hPa at sea level; the exact standard figure, 1013.25 hPa, is the same as 760 mmHg, 29.92 inHg or 101.3 kPa. Anything between roughly 1000 and 1025 hPa is ordinary. Which way it is going matters far more than the number itself.
Why does my own barometer show a different number?
Usually altitude, and sometimes the instrument itself. Weather services correct readings to what they would be at sea level, so that cities can be compared. The figure for Pretoria, which stands 1309 m above sea level, is in the note above: about 139 hPa below the sea-level reading. If your barometer is already set to sea level and still reads slightly differently, that is the setting on the instrument rather than the weather.
Is a millibar the same as a hectopascal?
Yes. One millibar and one hectopascal are exactly the same amount of pressure, so 1013 mbar and 1013 hPa mean the same thing. The name changed; the number did not.
Does falling pressure mean rain?
Not by itself. Away from the tropics, falling pressure usually means a low is approaching, and lows carry the fronts that bring cloud and rain, so the two often arrive together. But a shallow fall can pass with nothing more than cloud, and rain falls under steady pressure too. The graph tells you a system is on the way, not how wet it will be. The week ahead, just above, shows the rain forecast beside the pressure.
