barometer.today

Barometric pressure in Allentown

1010hPa
Falling

Pressure fell quickly over the past day. A drop of 7 hPa since this time yesterday. The fall is coming to an end: from here it climbs until Wednesday morning.

Sea level reading, as of 13:00 local time.

The past week and the days ahead

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

now30° / 20°28° / 21°30° / 18°28° / 18°26° / 15°24° / 19°26° / 19°24° / 16°25° / 15°28° / 16°29° / 20°28° / 20°28° / 20°16Mon 17Tue 18Wed 19Thu 20Fri 21Sat 22Sun 23Mon 24Tue 25Wed 26Thu 27Fri 28Sat 29101010151020
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 0 hPa

Dips overnight, and comes back by the end of the day.

Light drizzle26° / 19°3.9 mm

low 1009 · high 1013 hPa

MonAug 24 +3 hPa

Rises steadily through the day.

Light drizzle24° / 16°

low 1013 · high 1017 hPa

TueAug 25 +1 hPa

Edges up slowly through the day.

Overcast25° / 15°

low 1016 · high 1018 hPa

WedAug 26 −1 hPa

Eases down slowly through the day.

Overcast28° / 16°

low 1016 · high 1020 hPa

ThuAug 27 −2 hPa

Eases down slowly through the day.

Rain29° / 20°16.8 mm

low 1014 · high 1017 hPa

FriAug 28 +2 hPa

Edges up slowly through the day.

Light drizzle28° / 20°2.1 mm

low 1014 · high 1017 hPa

SatAug 29 +3 hPa

Edges up slowly through the day.

Light drizzle28° / 20°0.6 mm

low 1017 · high 1020 hPa

Hour by hour
Today Aug 23
HourWeather and temperatureRain (mm)Pressure (hPa)
00:00Drizzle20°0.71013
01:00Drizzle20°0.71012
02:00Drizzle20°0.71011
03:00Drizzle19°0.51011
04:00Drizzle19°0.51010
05:00Drizzle19°0.51009
06:00Partly cloudy19°1009
07:00Overcast19°1010
08:00Overcast20°1010
09:00Light drizzle21°0.11010
10:00Light drizzle22°0.11010
11:00Light drizzle23°0.11010
12:00Clear sky24°1010
13:00Clear sky25°1010
14:00Clear sky26°1010
15:00Clear sky26°1010
16:00Clear sky26°1010
17:00Clear sky25°1010
18:00Clear sky24°1010
19:00Clear sky23°1011
20:00Clear sky21°1011
21:00Clear sky20°1012
22:00Clear sky20°1012
23:00Clear sky19°1013

Monday has the week's biggest move: up 3 hPa.

What happens next

The high point comes on Wednesday morning, near 1020 hPa; after that it falls.

Your own barometer

Allentown sits 97 m above sea level, so a barometer in the city reads about 11 hPa lower than the sea-level figure. A home station set to the local reading should show about 999 hPa as of 13:00.

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 Allentown.

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 Allentown 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 Allentown, which stands 97 m above sea level, is in the note above: about 11 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.