Barometric pressure in Santos
Pressure has barely moved over the past day. A climb is beginning, and runs until tomorrow 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.
The week ahead
Each day at a glance: how far pressure moves, and the low and high it reaches.
Edges up slowly through the day.
21° / 16°2.8 mmlow 1020 · high 1023 hPa
Climbs in the morning, then settles back.
18° / 17°19.2 mmlow 1022 · high 1025 hPa
Falls steadily through the day.
20° / 18°6.7 mmlow 1019 · high 1022 hPa
Falls steadily through the day.
22° / 18°1.6 mmlow 1016 · high 1019 hPa
Falls steadily through the day.
24° / 18°low 1012 · high 1017 hPa
Falls steadily through the day.
29° / 19°low 1008 · high 1013 hPa
Rises steadily through the day.
32° / 22°low 1007 · high 1012 hPa
Hour by hour
| Hour | Weather and temperature | Rain (mm) | Pressure (hPa) |
|---|---|---|---|
| 00:00 |  18° | 1022 | |
| 01:00 |  17° | 1021 | |
| 02:00 | 17° | 1021 | |
| 03:00 | 17° | 1020 | |
| 04:00 | 16° | 1020 | |
| 05:00 | 16° | 1020 | |
| 06:00 | 16° | 1021 | |
| 07:00 |  17° | 1021 | |
| 08:00 | 19° | 1022 | |
| 09:00 | 20° | 1022 | |
| 10:00 | 20° | 1022 | |
| 11:00 | 21° | 1022 | |
| 12:00 | 21° | 1021 | |
| 13:00 | 21° | 0.1 | 1021 |
| 14:00 | 21° | 0.1 | 1021 |
| 15:00 | 21° | 0.1 | 1020 |
| 16:00 | 20° | 0.2 | 1021 |
| 17:00 | 20° | 0.2 | 1021 |
| 18:00 | 19° | 0.2 | 1022 |
| 19:00 | 19° | 0.3 | 1022 |
| 20:00 | 18° | 0.3 | 1023 |
| 21:00 | 18° | 0.3 | 1023 |
| 22:00 | 18° | 0.5 | 1023 |
| 23:00 | 18° | 0.5 | 1023 |
Biggest change: Friday, down 4 hPa.
The high point comes tomorrow morning, near 1025 hPa; after that it falls.
Santos is at sea level, so a barometer there reads about the same as the sea-level figure.
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 Santos.
Cities nearby
Open one to see its pressure, or search for your own city at the top of the page.
Is this weather normal for the season? See how these days compare with Santos weather 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. Weather services correct readings to what they would be at sea level, so that cities can be compared. Santos is at sea level, so there is almost nothing to correct and the two figures agree.
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.
