Barometric pressure in Fullerton today
Falling
Daily swings aside, pressure has eased down over the past day. It is 2 hPa lower than this time yesterday. Day by day, it holds near this level until Sunday, then falls slowly until Monday. After that it rises slowly for the rest of the week.
Current sea-level reading for Fullerton, as of 05:00 local time.
Pressure graph: the past week and the week ahead
The shaded part shows the days already gone. The thicker line is the forecast.
Fullerton sits 52 m above sea level, so a barometer in the city reads about 6 hPa lower than the sea-level figure. A home station set to the local reading should show about 1008 hPa as of 05:00.
The week ahead: the pressure forecast day by day
Each day at a glance: which way pressure moves, and how far.
34° / 23°Goes between 1013 and 1015 hPa and ends a little higher.Show hourly graph
32° / 24°Goes between 1013 and 1016 hPa and ends about where it started.Show hourly graph29° / 21°Falls steadily to 1011 by the afternoon, then edges back up a little.Show hourly graph25° / 19°Holds near 1013 until the afternoon, then falls steadily to 1009 by evening, then edges back up a little.Show hourly graph21° / 18°Eases down to 1010 overnight, then edges back up a little.Show hourly graph
19° / 15°24.3 mmEdges up to 1013 by morning, then eases back a little.Show hourly graph
20° / 14°1.8 mmHolds near 1012 until morning, then rises steadily to 1015 by the end of the day.Show hourly graphBiggest change of the week: Thursday, up 3 hPa.
Hour by hour
| Hour | Weather and temperature | Rain (mm) | Pressure (hPa) |
|---|---|---|---|
| 00:00 |  26° | 1014 | |
| 01:00 | 25° | 1014 | |
| 02:00 | 25° | 1014 | |
| 03:00 | 24° | 1014 | |
| 04:00 | 24° | 1014 | |
| 05:00 | 23° | 1014 | |
| 06:00 | 23° | 1015 | |
| 07:00 | 23° | 1015 | |
| 08:00 | 23° | 1015 | |
| 09:00 | 25° | 1015 | |
| 10:00 | 28° | 1015 | |
| 11:00 | 30° | 1015 | |
| 12:00 | 32° | 1015 | |
| 13:00 |  33° | 1014 | |
| 14:00 | 34° | 1013 | |
| 15:00 | 34° | 1013 | |
| 16:00 | 34° | 1013 | |
| 17:00 | 34° | 1013 | |
| 18:00 | 33° | 1013 | |
| 19:00 | 31° | 1014 | |
| 20:00 | 30° | 1015 | |
| 21:00 | 29° | 1015 | |
| 22:00 | 29° | 1015 | |
| 23:00 | 28° | 1015 |
How much the pressure changes in Fullerton
In Fullerton the pressure changes most from December to March. In a typical October it changes by about 1.3 hPa from one day to the next, and it hardly ever rises or falls by more than 10 hPa.
When the pressure changes most
| Month | More than 5 hPa | More than 10 hPa |
|---|---|---|
| January | 3 | 0 |
| February | 4 | 0 |
| March | 3 | 0 |
| April | 2 | 0 |
| May | 0 | 0 |
| June | 0 | 0 |
| July | 0 | 0 |
| August | 0 | 0 |
| September | 0 | 0 |
| October | 1 | 0 |
| November | 2 | 0 |
| December | 4 | 0 |
Does the pressure change a lot in Fullerton?
Fullerton has more days with a change of more than 10 hPa than 48 out of every 100 large cities.
Each dot stands for up to 20 cities with 100,000 people or more. The first column is much taller than shown. Cities higher than 1,000 m are left out, and so are smaller cities within 15 km of a bigger one, unless they are capitals, so that suburbs are not counted twice.
These figures come from ERA5, in which the European weather centre ECMWF rebuilds past weather from a weather model and observations, for an area about 28 km across around Fullerton, 1991 to 2020. Each change is the difference between one day’s average pressure and the next day’s.
Cities nearby
Open one to see its pressure, or search for your own city at the top of the page.
More about air pressure
What we have written about how pressure behaves and how it is measured.
Where air pressure changes the most, city by city
Thirty years of data, ranked by city: where air pressure swings most from day to day and where it hardly moves. London, New York, Tokyo and 128 more.
How much does air pressure change in a day?
A normal day moves the barometer about 4 hPa in London and half of one in Singapore. What counts as a big drop, and how often one comes.
Why barometric pressure deserved its own site
Air pressure is the weather number people ask about most and understand least: is it high, is it rising or falling, does it matter today.
Is this weather normal for the season? See how these days compare with Fullerton weather since 1940, on our sister site 
weatherjourney.com.
Questions about the pressure in Fullerton
What is the barometer reading in Fullerton right now?
Sea-level pressure in Fullerton is 1014 hPa as of 05:00 local time, unchanged over the last three hours. A barometer in the city itself, 52 m up, shows about 1008 hPa.
Is the barometer rising or falling in Fullerton today?
Daily swings aside, pressure has eased down over the past day. It is 2 hPa lower than this time yesterday. Over the last three hours it has not changed.
Has the pressure in Fullerton changed since yesterday?
Yes. At this time yesterday it read 1016 hPa; it is 2 hPa lower now.
What has the pressure in Fullerton been over the last few days?
Over the past 7 days it ran between 996 hPa (on Saturday night) and 1018 hPa (on Wednesday morning). The biggest change in any 24 hours was a rise of 14 hPa, in the 24 hours ending on Sunday night.
Is 1014 hPa high or low pressure?
Atmospheric pressure between about 1000 and 1025 hPa is ordinary at sea level. 1014 hPa sits in the middle of that range. In Fullerton most days average between 1009 and 1021 hPa. The last 24 hours average about 1014 hPa, within that usual range.
What is normal barometric pressure for Fullerton?
From 1991 to 2020 the sea-level average for Fullerton was 1015 hPa, and most days average between 1009 and 1021 hPa. It is usually highest in December and January and lowest from June to September.
When does barometric pressure change the most in Fullerton?
The pressure in Fullerton changes most from December to March. Between 1991 and 2020, Fullerton had about one day a year with a big change, of more than 10 hPa from one day to the next.
Why does my own barometer show a different number?
Usually altitude, and sometimes the instrument itself. To compare cities, pressure is corrected to sea level. The figure for Fullerton, which stands 52 m above sea level, is in the note above: about 6 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.
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.
