WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Assab 14 Day Long Range Forecast

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

Ethiopia

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

Reviewing the forecast for Assab Over the next 14 days and the average daytime maximum temperature will be around 37°C, with a high for the two weeks of 38°C expected on the afternoon of Sunday 10th. The average minimum temperature will be 31°C, dipping to its lowest on the morning of Tuesday 5th at 26°C. Expect the following 14 days ahead to remain predominantly dry. On the whole winds are likely to be moderate. The forecast suggests the strongest wind will be on the evening of Friday 1st, coming from a north easterly direction, and reaching around 29mph.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Thu 31
Jul
21:00

NNW
NNW

17 / 20 mph 92 / 113°F 72% 1005 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: medium
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 01
Aug
00:00

NW
NW

11 / 13 mph 92 / 116°F 75% 1004 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 9%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

12 / 14 mph 95 / 116°F 66% 1002 mb
Low level cloud: 0%
Mid level cloud: 41%
High level cloud: 6%
Most Significant Cloud Type: medium
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNW
NNW

15 / 17 mph 93 / 114°F 74% 1002 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: medium
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WNW
WNW

9 / 11 mph 98 / 123°F 64% 1004 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 0%
Most Significant Cloud Type: medium
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

N
N

11 / 14 mph 99 / 125°F 64% 1003 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 0%
Most Significant Cloud Type: medium
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

N
N

17 / 20 mph 99 / 126°F 62% 1001 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

29 / 33 mph 92 / 106°F 65% 1003 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 22%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WNW
WNW

13 / 14 mph 92 / 109°F 69% 1005 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 21%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 02
Aug
00:00

NW
NW

20 / 31 mph 87 / 99°F 74% 1003 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 6%
Most Significant Cloud Type: medium
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

14 / 17 mph 91 / 108°F 67% 1004 mb
Low level cloud: 0%
Mid level cloud: 51%
High level cloud: 8%
Most Significant Cloud Type: medium
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WSW
WSW

19 / 33 mph 88 / 94°F 58% 1005 mb
Low level cloud: 0%
Mid level cloud: 26%
High level cloud: 5%
Most Significant Cloud Type: medium
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WSW
WSW

19 / 22 mph 96 / 109°F 52% 1006 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 12%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

17 / 20 mph 101 / 115°F 46% 1005 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 3%
Most Significant Cloud Type: medium
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNW
NNW

11 / 17 mph 99 / 115°F 51% 1002 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 4%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

27 / 39 mph 92 / 107°F 66% 1004 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 3%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

22 / 39 mph 88 / 100°F 70% 1005 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 73%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 03
Aug
00:00

N
N

14 / 16 mph 90 / 108°F 72% 1006 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 81%
Most Significant Cloud Type: medium
48%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNW
NNW

12 / 16 mph 88 / 104°F 78% 1004 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 32%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

17 / 29 mph 88 / 99°F 77% 1005 mb
Low level cloud: 0%
Mid level cloud: 43%
High level cloud: 3%
Most Significant Cloud Type: medium
43%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NW
NW

15 / 23 mph 92 / 103°F 61% 1006 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 2%
Most Significant Cloud Type: medium
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NNW
NNW

15 / 17 mph 96 / 118°F 64% 1005 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 4%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

N
N

17 / 19 mph 98 / 128°F 67% 1003 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
12%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

N
N

15 / 18 mph 96 / 125°F 72% 1004 mb
Low level cloud: 0%
Mid level cloud: 31%
High level cloud: 0%
Most Significant Cloud Type: medium
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

15 / 17 mph 92 / 114°F 73% 1005 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 84%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 04
Aug
00:00

NNW
NNW

15 / 18 mph 91 / 108°F 72% 1005 mb
Low level cloud: 0%
Mid level cloud: 31%
High level cloud: 7%
Most Significant Cloud Type: medium
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

14 / 24 mph 88 / 98°F 65% 1004 mb
Low level cloud: 0%
Mid level cloud: 43%
High level cloud: 48%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WNW
WNW

4 / 9 mph 89 / 94°F 63% 1005 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 12%
Most Significant Cloud Type: medium
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NW
NW

6 / 10 mph 93 / 100°F 55% 1007 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 25%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

N
N

13 / 15 mph 96 / 112°F 57% 1005 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 6%
Most Significant Cloud Type: medium
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

N
N

12 / 14 mph 99 / 127°F 66% 1003 mb
Low level cloud: 0%
Mid level cloud: 48%
High level cloud: 3%
Most Significant Cloud Type: medium
48%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

7 / 8 mph 97 / 124°F 72% 1006 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 75%
Most Significant Cloud Type: medium
46%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

17 / 19 mph 92 / 111°F 68% 1005 mb
Low level cloud: 0%
Mid level cloud: 31%
High level cloud: 31%
Most Significant Cloud Type: medium
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 05
Aug
00:00

NW
NW

9 / 16 mph 87 / 98°F 71% 1005 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 19%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

S
S

9 / 19 mph 83 / 88°F 65% 1005 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 58%
Most Significant Cloud Type: medium
48%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SW
SW

5 / 11 mph 90 / 94°F 58% 1004 mb
Low level cloud: 0%
Mid level cloud: 20%
High level cloud: 18%
Most Significant Cloud Type: medium
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WSW
WSW

11 / 13 mph 97 / 110°F 52% 1005 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 10%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

N
N

11 / 15 mph 97 / 113°F 57% 1004 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 3%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNE
NNE

15 / 18 mph 96 / 115°F 60% 1002 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 4%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

N
N

15 / 27 mph 89 / 100°F 69% 1002 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

12 / 22 mph 87 / 98°F 73% 1004 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 3%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 06
Aug
00:00

NW
NW

10 / 14 mph 90 / 105°F 72% 1003 mb
Low level cloud: 0%
Mid level cloud: 66%
High level cloud: 3%
Most Significant Cloud Type: medium
66%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

10 / 16 mph 87 / 101°F 77% 1003 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SSE
SSE

4 / 8 mph 89 / 95°F 72% 1004 mb
Low level cloud: 0%
Mid level cloud: 21%
High level cloud: 3%
Most Significant Cloud Type: medium
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ENE
ENE

5 / 7 mph 92 / 101°F 62% 1005 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

N
N

11 / 13 mph 95 / 111°F 60% 1004 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNW
NNW

17 / 19 mph 97 / 120°F 64% 1002 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

N
N

20 / 23 mph 95 / 120°F 71% 1003 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 0%
Most Significant Cloud Type: medium
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

22 / 26 mph 91 / 109°F 71% 1004 mb
Low level cloud: 0%
Mid level cloud: 70%
High level cloud: 0%
Most Significant Cloud Type: medium
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Thu 07
Aug
03:00

NW
NW

11 / 19 mph 90 / 100°F 61% 1000 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 4%
Most Significant Cloud Type: medium
46%
0.0 In
09:00

ENE
ENE

4 / 5 mph 90 / 105°F 70% 1003 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 6%
Most Significant Cloud Type: medium
10%
0.0 In
15:00

N
N

18 / 21 mph 98 / 120°F 58% 1000 mb
Low level cloud: 0%
Mid level cloud: 52%
High level cloud: 0%
Most Significant Cloud Type: medium
51%
0.0 In
21:00

NW
NW

21 / 24 mph 93 / 110°F 64% 1003 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 11%
Most Significant Cloud Type: medium
46%
0.0 In
Fri 08
Aug
03:00

WNW
WNW

20 / 42 mph 88 / 92°F 51% 999 mb
Low level cloud: 0%
Mid level cloud: 33%
High level cloud: 0%
Most Significant Cloud Type: medium
32%
0.0 In
09:00

NW
NW

8 / 12 mph 91 / 100°F 57% 1004 mb
Low level cloud: 0%
Mid level cloud: 43%
High level cloud: 11%
Most Significant Cloud Type: medium
43%
0.0 In
15:00

N
N

16 / 20 mph 100 / 134°F 65% 1002 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 4%
Most Significant Cloud Type: medium
10%
0.0 In
21:00

NNW
NNW

19 / 22 mph 91 / 115°F 78% 1004 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: medium
24%
0.0 In
Sat 09
Aug
03:00

N
N

13 / 19 mph 89 / 102°F 69% 1001 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 10%
Most Significant Cloud Type: medium
44%
0.0 In
09:00

WNW
WNW

13 / 20 mph 92 / 103°F 58% 1005 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: medium
29%
0.0 In
15:00

NNE
NNE

15 / 19 mph 97 / 121°F 62% 1002 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 1%
Most Significant Cloud Type: medium
8%
0.0 In
21:00

N
N

8 / 9 mph 93 / 119°F 76% 1005 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 93%
Most Significant Cloud Type: medium
48%
0.0 In
Sun 10
Aug
03:00

WNW
WNW

7 / 11 mph 89 / 98°F 59% 1002 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 32%
Most Significant Cloud Type: medium
15%
0.0 In
09:00

WNW
WNW

12 / 22 mph 91 / 99°F 53% 1004 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 38%
Most Significant Cloud Type: medium
15%
0.0 In
15:00

NNE
NNE

16 / 21 mph 97 / 119°F 58% 1001 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 6%
Most Significant Cloud Type: medium
30%
0.0 In
21:00

N
N

11 / 14 mph 92 / 112°F 72% 1003 mb
Low level cloud: 0%
Mid level cloud: 63%
High level cloud: 7%
Most Significant Cloud Type: medium
63%
0.0 In
Mon 11
Aug
03:00

WNW
WNW

6 / 12 mph 90 / 98°F 57% 1001 mb
Low level cloud: 0%
Mid level cloud: 50%
High level cloud: 81%
Most Significant Cloud Type: medium
53%
0.0 In
09:00

ENE
ENE

5 / 6 mph 93 / 108°F 63% 1003 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 7%
Most Significant Cloud Type: medium
6%
0.0 In
15:00

N
N

14 / 19 mph 99 / 126°F 61% 999 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 19%
Most Significant Cloud Type: medium
46%
0.0 In
21:00

WNW
WNW

13 / 15 mph 94 / 109°F 59% 1001 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 19%
Most Significant Cloud Type: medium
17%
0.0 In
Tue 12
Aug
03:00

WNW
WNW

9 / 15 mph 90 / 100°F 62% 1001 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 32%
Most Significant Cloud Type: medium
23%
0.0 In
09:00

ESE
ESE

9 / 11 mph 90 / 104°F 68% 1004 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 33%
Most Significant Cloud Type: medium
7%
0.0 In
15:00

ENE
ENE

6 / 9 mph 98 / 118°F 57% 999 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 9%
Most Significant Cloud Type: medium
5%
0.0 In
21:00

NW
NW

8 / 14 mph 91 / 101°F 57% 1003 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 19%
Most Significant Cloud Type: medium
6%
0.0 In
Wed 13
Aug
03:00

WNW
WNW

11 / 15 mph 89 / 103°F 68% 1002 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: medium
10%
0.0 In
09:00

SE
SE

6 / 9 mph 91 / 105°F 67% 1006 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 94%
Most Significant Cloud Type: medium
49%
0.0 In
15:00

N
N

15 / 22 mph 98 / 128°F 66% 1000 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
21:00

NNW
NNW

15 / 19 mph 91 / 113°F 75% 1005 mb
Low level cloud: 0%
Mid level cloud: 32%
High level cloud: 1%
Most Significant Cloud Type: medium
31%
0.0 In
Thu 14
Aug
03:00

NW
NW

8 / 11 mph 89 / 104°F 73% 1003 mb
Low level cloud: 0%
Mid level cloud: 63%
High level cloud: 33%
Most Significant Cloud Type: medium
64%
0.0 In
09:00

NW
NW

17 / 26 mph 92 / 105°F 61% 1004 mb
Low level cloud: 0%
Mid level cloud: 28%
High level cloud: 0%
Most Significant Cloud Type: medium
28%
0.0 In
15:00

NNW
NNW

6 / 9 mph 96 / 123°F 68% 1001 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 32%
Most Significant Cloud Type: medium
45%
0.0 In
21:00

ENE
ENE

13 / 21 mph 93 / 114°F 69% 1004 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 21%
Most Significant Cloud Type: medium
29%
0.1 In
Fri 15
Aug
03:00

WSW
WSW

15 / 32 mph 78 / 83°F 81% 1005 mb
Low level cloud: 42%
Mid level cloud: 94%
High level cloud: 100%
Most Significant Cloud Type: low
87%
2.0 In
09:00

WSW
WSW

10 / 18 mph 91 / 99°F 53% 1002 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 14%
Most Significant Cloud Type: medium
12%
0.1 In
15:00

WSW
WSW

25 / 52 mph 86 / 101°F 81% 1005 mb
Low level cloud: 82%
Mid level cloud: 60%
High level cloud: 97%
Most Significant Cloud Type: low
100%
2.5 In
21:00

NW
NW

5 / 10 mph 90 / 101°F 60% 1000 mb
Low level cloud: 0%
Mid level cloud: 41%
High level cloud: 98%
Most Significant Cloud Type: medium
44%
0.0 In

Other Locations Near to Assab

Cities and Towns: Aseb, Eritrea

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