Fast Forecast

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Atherington 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Atherington

West Sussex, United Kingdom

Long range weather outlook for Atherington includes 14 day forecast summary:

Taking a look at Atherington over the coming two weeks and the average daytime maximum temperature will be around 10°C, with a high for the two weeks of 13°C expected on the afternoon of Thursday 20th. The average minimum temperature will be 6°C, dipping to its lowest on the morning of Sunday 16th at 4°C. Expect the coming 14 days to have mixed weather with some days dry and some seeing a little rain. Predictions are Friday 21st will have the most precipitation with an accumulation of around 4.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Sun 16
Mar		21:00

NE
NE

 12 / 13 mph 42 / 36°F 83% 1027 mb
Low level cloud: 13%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 17
Mar		00:00

NE
NE

 10 / 15 mph 40 / 33°F 87% 1027 mb
Low level cloud: 10%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NE
NE

 10 / 15 mph 40 / 34°F 89% 1026 mb
Low level cloud: 73%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
73%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

 15 / 20 mph 42 / 34°F 91% 1027 mb
Low level cloud: 87%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
87%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

 18 / 25 mph 42 / 34°F 82% 1028 mb
Low level cloud: 73%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
73%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ENE
ENE

 15 / 21 mph 45 / 38°F 69% 1028 mb
Low level cloud: 77%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
76%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

E
E

 16 / 23 mph 46 / 38°F 69% 1026 mb
Low level cloud: 21%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

E
E

 15 / 24 mph 43 / 35°F 76% 1026 mb
Low level cloud: 26%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: low
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

 17 / 26 mph 41 / 33°F 82% 1027 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 18
Mar		00:00

ENE
ENE

 16 / 22 mph 43 / 35°F 81% 1026 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

 16 / 26 mph 41 / 33°F 76% 1025 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

E
E

 17 / 29 mph 39 / 30°F 73% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

E
E

 21 / 26 mph 43 / 34°F 62% 1025 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

E
E

 19 / 22 mph 47 / 40°F 56% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

E
E

 18 / 21 mph 49 / 42°F 57% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

 16 / 21 mph 47 / 40°F 67% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 5%
Most Significant Cloud Type: high
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

 12 / 15 mph 47 / 41°F 76% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 19
Mar		00:00

E
E

 11 / 17 mph 44 / 38°F 82% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

 8 / 14 mph 43 / 38°F 88% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

E
E

 8 / 15 mph 43 / 38°F 89% 1021 mb
Low level cloud: 3%
Mid level cloud: 7%
High level cloud: 12%
Most Significant Cloud Type: low
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ESE
ESE

 10 / 15 mph 47 / 42°F 85% 1021 mb
Low level cloud: 5%
Mid level cloud: 6%
High level cloud: 20%
Most Significant Cloud Type: low
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SE
SE

 9 / 13 mph 49 / 45°F 82% 1021 mb
Low level cloud: 1%
Mid level cloud: 4%
High level cloud: 11%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ESE
ESE

 7 / 12 mph 49 / 46°F 79% 1021 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 7%
Most Significant Cloud Type: medium
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

E
E

 8 / 15 mph 49 / 45°F 83% 1020 mb
Low level cloud: 2%
Mid level cloud: 3%
High level cloud: 36%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

 9 / 18 mph 47 / 43°F 83% 1021 mb
Low level cloud: 65%
Mid level cloud: 19%
High level cloud: 97%
Most Significant Cloud Type: low
82%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 20
Mar		00:00

E
E

 7 / 15 mph 49 / 46°F 82% 1020 mb
Low level cloud: 89%
Mid level cloud: 32%
High level cloud: 32%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

 8 / 17 mph 47 / 44°F 83% 1019 mb
Low level cloud: 29%
Mid level cloud: 100%
High level cloud: 8%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

ENE
ENE

 9 / 18 mph 46 / 42°F 84% 1018 mb
Low level cloud: 16%
Mid level cloud: 30%
High level cloud: 0%
Most Significant Cloud Type: low
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

E
E

 10 / 14 mph 50 / 45°F 83% 1018 mb
Low level cloud: 3%
Mid level cloud: 66%
High level cloud: 5%
Most Significant Cloud Type: medium
75%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

E
E

 10 / 11 mph 54 / 50°F 81% 1017 mb
Low level cloud: 1%
Mid level cloud: 32%
High level cloud: 0%
Most Significant Cloud Type: medium
34%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

E
E

 10 / 11 mph 56 / 53°F 81% 1014 mb
Low level cloud: 11%
Mid level cloud: 12%
High level cloud: 77%
Most Significant Cloud Type: low
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

 10 / 14 mph 55 / 51°F 83% 1013 mb
Low level cloud: 26%
Mid level cloud: 8%
High level cloud: 98%
Most Significant Cloud Type: low
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

 10 / 18 mph 51 / 47°F 84% 1012 mb
Low level cloud: 53%
Mid level cloud: 83%
High level cloud: 32%
Most Significant Cloud Type: low
86%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 21
Mar		00:00

ENE
ENE

 10 / 21 mph 49 / 45°F 86% 1010 mb
Low level cloud: 4%
Mid level cloud: 47%
High level cloud: 72%
Most Significant Cloud Type: medium
60%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NE
NE

 9 / 18 mph 47 / 43°F 94% 1008 mb
Low level cloud: 52%
Mid level cloud: 84%
High level cloud: 100%
Most Significant Cloud Type: low
93%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
06:00

ENE
ENE

 9 / 18 mph 46 / 42°F 97% 1007 mb
Low level cloud: 100%
Mid level cloud: 100%
High level cloud: 11%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SSE
SSE

 6 / 10 mph 49 / 46°F 98% 1006 mb
Low level cloud: 100%
Mid level cloud: 78%
High level cloud: 2%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
12:00

SSW
SSW

 9 / 13 mph 52 / 48°F 98% 1007 mb
Low level cloud: 99%
Mid level cloud: 44%
High level cloud: 3%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WSW
WSW

 13 / 16 mph 53 / 49°F 91% 1007 mb
Low level cloud: 71%
Mid level cloud: 17%
High level cloud: 19%
Most Significant Cloud Type: low
79%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

 12 / 15 mph 53 / 48°F 93% 1007 mb
Low level cloud: 22%
Mid level cloud: 9%
High level cloud: 5%
Most Significant Cloud Type: low
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

 11 / 15 mph 51 / 47°F 93% 1007 mb
Low level cloud: 4%
Mid level cloud: 6%
High level cloud: 14%
Most Significant Cloud Type: low
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 22
Mar		00:00

WNW
WNW

 5 / 9 mph 48 / 46°F 93% 1007 mb
Low level cloud: 8%
Mid level cloud: 9%
High level cloud: 17%
Most Significant Cloud Type: low
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

 3 / 5 mph 46 / 46°F 93% 1007 mb
Low level cloud: 16%
Mid level cloud: 15%
High level cloud: 4%
Most Significant Cloud Type: low
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

 5 / 9 mph 46 / 42°F 92% 1007 mb
Low level cloud: 25%
Mid level cloud: 7%
High level cloud: 100%
Most Significant Cloud Type: low
38%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNW
NNW

 6 / 9 mph 49 / 45°F 89% 1009 mb
Low level cloud: 30%
Mid level cloud: 10%
High level cloud: 100%
Most Significant Cloud Type: low
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NNW
NNW

 5 / 8 mph 51 / 48°F 83% 1009 mb
Low level cloud: 63%
Mid level cloud: 8%
High level cloud: 26%
Most Significant Cloud Type: low
69%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NW
NW

 3 / 5 mph 53 / 52°F 77% 1008 mb
Low level cloud: 68%
Mid level cloud: 5%
High level cloud: 6%
Most Significant Cloud Type: low
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

 5 / 9 mph 52 / 50°F 75% 1008 mb
Low level cloud: 82%
Mid level cloud: 5%
High level cloud: 4%
Most Significant Cloud Type: low
84%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

 6 / 11 mph 50 / 47°F 79% 1009 mb
Low level cloud: 64%
Mid level cloud: 7%
High level cloud: 3%
Most Significant Cloud Type: low
66%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Sun 23
Mar		00:00

SSE
SSE

 31 / 53 mph 46 / 37°F 88% 1000 mb
Low level cloud: 97%
Mid level cloud: 80%
High level cloud: 51%
Most Significant Cloud Type: low
100%
0.0 In
06:00

SSW
SSW

 7 / 11 mph 45 / 42°F 89% 1001 mb
Low level cloud: 5%
Mid level cloud: 97%
High level cloud: 30%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

SSW
SSW

 19 / 33 mph 48 / 42°F 83% 993 mb
Low level cloud: 16%
Mid level cloud: 44%
High level cloud: 97%
Most Significant Cloud Type: low
43%
0.0 In
18:00

ESE
ESE

 14 / 20 mph 51 / 46°F 98% 1005 mb
Low level cloud: 91%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
Mon 24
Mar		00:00

WSW
WSW

 3 / 5 mph 51 / 51°F 92% 1003 mb
Low level cloud: 28%
Mid level cloud: 30%
High level cloud: 22%
Most Significant Cloud Type: low
40%
0.0 In
06:00

WNW
WNW

 3 / 4 mph 47 / 47°F 93% 1004 mb
Low level cloud: 24%
Mid level cloud: 75%
High level cloud: 3%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

SSW
SSW

 18 / 26 mph 50 / 44°F 88% 1005 mb
Low level cloud: 44%
Mid level cloud: 69%
High level cloud: 32%
Most Significant Cloud Type: low
72%
0.0 In
18:00

WSW
WSW

 20 / 31 mph 52 / 46°F 85% 1011 mb
Low level cloud: 23%
Mid level cloud: 17%
High level cloud: 10%
Most Significant Cloud Type: low
30%
0.0 In
Tue 25
Mar		00:00

WNW
WNW

 6 / 9 mph 51 / 49°F 86% 1021 mb
Low level cloud: 0%
Mid level cloud: 54%
High level cloud: 32%
Most Significant Cloud Type: medium
54%
0.0 In
06:00

NW
NW

 9 / 14 mph 43 / 37°F 83% 1017 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
12:00

W
W

 10 / 15 mph 52 / 49°F 80% 1021 mb
Low level cloud: 9%
Mid level cloud: 55%
High level cloud: 6%
Most Significant Cloud Type: medium
81%
0.0 In
18:00

WNW
WNW

 4 / 6 mph 49 / 47°F 69% 1019 mb
Low level cloud: 33%
Mid level cloud: 44%
High level cloud: 40%
Most Significant Cloud Type: low
53%
0.0 In
Wed 26
Mar		00:00

WNW
WNW

 6 / 8 mph 52 / 51°F 92% 1020 mb
Low level cloud: 10%
Mid level cloud: 46%
High level cloud: 32%
Most Significant Cloud Type: medium
75%
0.0 In
06:00

NNW
NNW

 8 / 12 mph 42 / 37°F 83% 1021 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 3%
Most Significant Cloud Type: medium
5%
0.0 In
12:00

WSW
WSW

 6 / 7 mph 58 / 57°F 86% 1019 mb
Low level cloud: 18%
Mid level cloud: 43%
High level cloud: 18%
Most Significant Cloud Type: low
35%
0.0 In
18:00

WSW
WSW

 9 / 16 mph 46 / 41°F 81% 1022 mb
Low level cloud: 62%
Mid level cloud: 92%
High level cloud: 1%
Most Significant Cloud Type: low
94%
0.0 In
Thu 27
Mar		00:00

WNW
WNW

 6 / 12 mph 49 / 46°F 86% 1017 mb
Low level cloud: 0%
Mid level cloud: 33%
High level cloud: 5%
Most Significant Cloud Type: medium
32%
0.0 In
06:00

WNW
WNW

 6 / 9 mph 48 / 46°F 83% 1022 mb
Low level cloud: 40%
Mid level cloud: 12%
High level cloud: 8%
Most Significant Cloud Type: low
45%
0.0 In
12:00

WNW
WNW

 2 / 2 mph 58 / 58°F 85% 1015 mb
Low level cloud: 95%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

WSW
WSW

 9 / 13 mph 53 / 50°F 78% 1023 mb
Low level cloud: 19%
Mid level cloud: 3%
High level cloud: 8%
Most Significant Cloud Type: low
21%
0.0 In
Fri 28
Mar		00:00

NW
NW

 9 / 13 mph 44 / 40°F 89% 1011 mb
Low level cloud: 78%
Mid level cloud: 82%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.2 In
06:00

ESE
ESE

 3 / 4 mph 52 / 52°F 80% 1025 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 1%
Most Significant Cloud Type: medium
3%
0.0 In
12:00

SSW
SSW

 15 / 21 mph 49 / 44°F 77% 1003 mb
Low level cloud: 55%
Mid level cloud: 100%
High level cloud: 49%
Most Significant Cloud Type: low
96%
0.0 In
18:00

E
E

 5 / 9 mph 57 / 56°F 78% 1026 mb
Low level cloud: 0%
Mid level cloud: 1%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Sat 29
Mar		00:00

SSW
SSW

 12 / 21 mph 45 / 39°F 89% 989 mb
Low level cloud: 91%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
06:00

NNE
NNE

 7 / 14 mph 48 / 45°F 87% 1027 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 19%
Most Significant Cloud Type: medium
7%
0.0 In
12:00

WNW
WNW

 18 / 33 mph 45 / 38°F 70% 990 mb
Low level cloud: 72%
Mid level cloud: 32%
High level cloud: 28%
Most Significant Cloud Type: low
87%
0.0 In
18:00

ESE
ESE

 3 / 4 mph 61 / 61°F 80% 1026 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 15%
Most Significant Cloud Type: medium
8%
0.0 In
Sun 30
Mar		00:00

NW
NW

 7 / 13 mph 41 / 36°F 88% 992 mb
Low level cloud: 81%
Mid level cloud: 32%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
06:00

NNE
NNE

 9 / 18 mph 46 / 42°F 84% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
12:00

N
N

 21 / 39 mph 39 / 29°F 95% 1000 mb
Low level cloud: 86%
Mid level cloud: 44%
High level cloud: 33%
Most Significant Cloud Type: low
100%
0.3 In
18:00

ENE
ENE

 10 / 16 mph 56 / 54°F 79% 1018 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Mon 31
Mar		00:00

NNW
NNW

 19 / 36 mph 42 / 34°F 89% 1004 mb
Low level cloud: 94%
Mid level cloud: 97%
High level cloud: 92%
Most Significant Cloud Type: low
100%
0.0 In
06:00

NE
NE

 13 / 22 mph 45 / 39°F 82% 1016 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
0.0 In
12:00

NNW
NNW

 21 / 40 mph 41 / 32°F 73% 1008 mb
Low level cloud: 73%
Mid level cloud: 98%
High level cloud: 75%
Most Significant Cloud Type: low
100%
0.1 In
18:00

NE
NE

 20 / 32 mph 50 / 44°F 66% 1020 mb
Low level cloud: 48%
Mid level cloud: 11%
High level cloud: 22%
Most Significant Cloud Type: low
54%
0.0 In

The day label given represents the local day relative to the local time for the location you are looking at.
(More Info)

Day

This time is corrected for local time zones and where possible for daylight saving times.
(More Info)

Local Time

The wind direction we use on this page is the direction the wind is coming from, given in a 16 point compass format.
(More Info)

Dir

This refers to the sustained average wind speed, normally averaged over a period of 10 minutes for up to 3 hrs.
(More Info)

Speed/
Gust

Temperature from our forecast perspective are fairly well defined, they are what we would expect to measure in a standard meteorological screen (in other words, shaded and well ventilated) at 2 metres above ground level.
(More Info)

Temp/
Feels Like

The relative humidity is the percent of saturation humidity, generally calculated in relation to saturated vapour density.
(More Info)

Humidity

The value given is a total predicted for the previous 3 hrs and includes the time of the forecast being looked at.
(More Info)

Precip Amount

The total amount of cloud as a percentage is derived from looking at cloud cover throughout the atmosphere and estimating how these combine when looked at from the ground.
(More Info)

Cloud Amount

Here we try to capture the feel of the weather as an image – it will never be perfect but is useful for a quick overview.
(More Info)

Weather

When we measure for forecast air pressure we are normally doing this relative to a certain height and most commonly relative to Mean Sea Level.
(More Info)

Pressure