barometer.today

Barometric pressure in London

1010hPa
Falling

Air pressure fell slowly over the last 24 hours. Down 1 hPa since this time yesterday. The fall is coming to an end: from here it climbs until Tuesday morning.

Sea level reading, as of 12:00 local time.

The past week and the days ahead

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

now24° / 17°26° / 14°24° / 16°25° / 13°24° / 11°23° / 17°19° / 13°18° / 13°21° / 15°23° / 14°24° / 17°24° / 16°25° / 15°16Mon 17Tue 18Wed 19Thu 20Fri 21Sat 22Sun 23Mon 24Tue 25Wed 26Thu 27Fri 28Sat 291005101010151020
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 +4 hPa

Rises steadily through the day.

Drizzle19° / 13°6.9 mm

low 1008 · high 1012 hPa

MonAug 24 +4 hPa

Rises steadily through the day.

Light drizzle18° / 13°1.2 mm

low 1012 · high 1016 hPa

TueAug 25 +2 hPa

Edges up slowly through the day.

Light drizzle21° / 15°

low 1016 · high 1019 hPa

WedAug 26 −6 hPa

Falls steadily through the day.

Light drizzle23° / 14°0.6 mm

low 1012 · high 1018 hPa

ThuAug 27 +2 hPa

Edges up slowly through the day.

Light drizzle24° / 17°3.0 mm

low 1011 · high 1014 hPa

FriAug 28 +5 hPa

Rises steadily through the day.

Overcast24° / 16°

low 1014 · high 1019 hPa

SatAug 29 −1 hPa

Eases down slowly through the day.

Light drizzle25° / 15°1.8 mm

low 1018 · high 1022 hPa

Hour by hour
Today Aug 23
HourWeather and temperatureRain (mm)Pressure (hPa)
00:00Partly cloudy17°1009
01:00Partly cloudy16°1008
02:00Partly cloudy16°1008
03:00Partly cloudy15°1008
04:00Partly cloudy15°1008
05:00Partly cloudy15°1008
06:00Drizzle15°0.51009
07:00Drizzle15°0.51009
08:00Drizzle15°0.51009
09:00Light drizzle15°0.41010
10:00Light drizzle16°0.41010
11:00Light drizzle17°0.41010
12:00Drizzle17°0.51010
13:00Drizzle18°0.51010
14:00Drizzle19°0.51010
15:00Drizzle19°0.51010
16:00Drizzle19°0.51010
17:00Drizzle19°0.51010
18:00Light drizzle18°0.31010
19:00Light drizzle17°0.31011
20:00Light drizzle16°0.31011
21:00Light drizzle15°0.11011
22:00Light drizzle14°0.11012
23:00Light drizzle13°0.11012

Biggest change: Wednesday, down 6 hPa.

What happens next

The high point comes on Tuesday morning, near 1019 hPa; after that it falls.

Your own barometer

London sits 251 m above sea level, so a barometer in the city reads about 29 hPa lower than the sea-level figure. A home station set to the local reading should show about 981 hPa as of 12:00.

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 London.

Cities nearby

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

Wondering if this weather is normal? See what the weather in London has done since 1940, on our sister site weatherjourney.com.

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 London, which stands 251 m above sea level, is in the note above: about 29 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.