barometer.today

Barometric pressure in Cape Town

1027hPa
Steady

A quiet stretch: pressure has barely moved over the past day. A fall is beginning, and runs until Friday afternoon.

Sea level reading, as of 17:00 local time.

The past week and the days ahead

The shaded part shows the days already gone. The thicker line is the forecast.

now17° / 10°19° / 9°19° / 11°18° / 11°22° / 11°18° / 11°19° / 11°18° / 12°19° / 13°25° / 11°25° / 13°27° / 13°15° / 11°Mon 17Tue 18Wed 19Thu 20Fri 21Sat 22Sun 23Mon 24Tue 25Wed 26Thu 27Fri 28Sat 2910101015102010251030
The forecast runs 7 days ahead.

The week ahead

Each day at a glance: how far pressure moves, and the low and high it reaches.

TodayAug 23 −3 hPa

Falls steadily through the day.

Clear sky19° / 11°

low 1027 · high 1030 hPa

MonAug 24 −4 hPa

Falls steadily through the day.

Clear sky18° / 12°

low 1022 · high 1026 hPa

TueAug 25 −2 hPa

Eases down slowly through the day.

Clear sky19° / 13°

low 1019 · high 1022 hPa

WedAug 26 −3 hPa

Eases down slowly through the day.

Overcast25° / 11°

low 1015 · high 1019 hPa

ThuAug 27 +1 hPa

Barely moves all day.

Overcast25° / 13°

low 1016 · high 1018 hPa

FriAug 28 −6 hPa

Falls quickly through the day.

Overcast27° / 13°

low 1011 · high 1018 hPa

SatAug 29 +8 hPa

Rises quickly through the day.

Drizzle15° / 11°7.8 mm

low 1011 · high 1020 hPa

Hour by hour
Today Aug 23
HourWeather and temperatureRain (mm)Pressure (hPa)
00:00Mainly clear12°1030
01:00Mainly clear12°1029
02:00Clear sky12°1029
03:00Clear sky12°1029
04:00Clear sky11°1029
05:00Clear sky11°1028
06:00Clear sky11°1029
07:00Clear sky11°1029
08:00Clear sky12°1029
09:00Clear sky13°1029
10:00Clear sky15°1029
11:00Clear sky17°1029
12:00Clear sky18°1029
13:00Clear sky19°1028
14:00Clear sky19°1027
15:00Clear sky19°1027
16:00Clear sky18°1027
17:00Clear sky17°1027
18:00Clear sky16°1027
19:00Clear sky14°1027
20:00Clear sky13°1027
21:00Clear sky13°1027
22:00Clear sky13°1027
23:00Clear sky13°1027

Of the seven days, Saturday moves most: up 8 hPa.

What happens next

The lowest reading, about 1011 hPa, comes on Friday afternoon; it climbs from there.

Your own barometer

Cape Town sits 25 m above sea level, so a barometer in the city reads about 3 hPa lower than the sea-level figure. A home station set to the local reading should show about 1024 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 Cape Town.

Cities nearby

Open one to see its pressure, or search for your own city at the top of the page.

Out in the sun today? Check the UV level in Cape Town, on our sister site uvi.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 Cape Town, which stands 25 m above sea level, is in the note above: about 3 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.