WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Saltmarsh 14 Day Long Range Forecast

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

City of Newport, United Kingdom

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

Taking a look at Saltmarsh over the coming two weeks and the average daytime maximum temperature will be around 9°C, with a high for the two weeks of 13°C expected on the afternoon of Saturday 16th. The mean minimum temperature will be 4°C, dipping to its lowest on the evening of Thursday 21st at -1°C. The next 14 days will have most days seeing a little rain, sleet or snow. It looks like Monday 18th will have the most precipitation with an accumulation of around 11.0mm. On the whole winds are likely to be moderate. The forecast suggests the strongest wind will be on the afternoon of Saturday 23rd, coming from a south westerly direction, and reaching around 26mph.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Thu 14
Nov
21:00

ENE
ENE

6 / 9 mph 48 / 45°F 86% 1032 mb
Low level cloud: 4%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: low
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 15
Nov
00:00

NE
NE

5 / 7 mph 46 / 44°F 87% 1031 mb
Low level cloud: 9%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

1 / 2 mph 45 / 45°F 87% 1030 mb
Low level cloud: 10%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SSW
SSW

2 / 4 mph 44 / 43°F 86% 1029 mb
Low level cloud: 7%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: low
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

3 / 4 mph 47 / 46°F 85% 1029 mb
Low level cloud: 6%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: low
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SW
SW

5 / 6 mph 52 / 50°F 78% 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
15:00

SW
SW

5 / 6 mph 54 / 52°F 79% 1025 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 5%
Most Significant Cloud Type: high
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

5 / 6 mph 52 / 50°F 84% 1025 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 100%
Most Significant Cloud Type: high
99%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

5 / 5 mph 49 / 48°F 86% 1025 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 31%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 16
Nov
00:00

WNW
WNW

4 / 8 mph 42 / 40°F 86% 1023 mb
Low level cloud: 1%
Mid level cloud: 0%
High level cloud: 32%
Most Significant Cloud Type: high
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

5 / 11 mph 42 / 38°F 85% 1022 mb
Low level cloud: 5%
Mid level cloud: 0%
High level cloud: 100%
Most Significant Cloud Type: medium
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

W
W

5 / 11 mph 42 / 39°F 86% 1021 mb
Low level cloud: 34%
Mid level cloud: 1%
High level cloud: 88%
Most Significant Cloud Type: low
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WSW
WSW

5 / 6 mph 50 / 48°F 88% 1021 mb
Low level cloud: 96%
Mid level cloud: 4%
High level cloud: 52%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WSW
WSW

9 / 11 mph 56 / 53°F 90% 1019 mb
Low level cloud: 88%
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
15:00

WSW
WSW

9 / 10 mph 56 / 54°F 93% 1018 mb
Low level cloud: 49%
Mid level cloud: 80%
High level cloud: 0%
Most Significant Cloud Type: low
76%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

7 / 8 mph 55 / 53°F 91% 1017 mb
Low level cloud: 18%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NW
NW

6 / 7 mph 52 / 51°F 90% 1017 mb
Low level cloud: 44%
Mid level cloud: 46%
High level cloud: 100%
Most Significant Cloud Type: low
72%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 17
Nov
00:00

NW
NW

5 / 9 mph 46 / 44°F 81% 1017 mb
Low level cloud: 22%
Mid level cloud: 94%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

5 / 9 mph 44 / 42°F 78% 1016 mb
Low level cloud: 82%
Mid level cloud: 100%
High level cloud: 8%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

W
W

7 / 14 mph 43 / 39°F 82% 1015 mb
Low level cloud: 6%
Mid level cloud: 100%
High level cloud: 99%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

W
W

10 / 14 mph 46 / 41°F 80% 1015 mb
Low level cloud: 21%
Mid level cloud: 27%
High level cloud: 12%
Most Significant Cloud Type: low
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WNW
WNW

15 / 19 mph 50 / 44°F 79% 1014 mb
Low level cloud: 77%
Mid level cloud: 32%
High level cloud: 0%
Most Significant Cloud Type: low
87%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

14 / 16 mph 51 / 47°F 74% 1014 mb
Low level cloud: 2%
Mid level cloud: 28%
High level cloud: 32%
Most Significant Cloud Type: medium
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NW
NW

12 / 14 mph 50 / 45°F 79% 1016 mb
Low level cloud: 43%
Mid level cloud: 35%
High level cloud: 19%
Most Significant Cloud Type: low
58%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WNW
WNW

9 / 10 mph 47 / 43°F 80% 1016 mb
Low level cloud: 19%
Mid level cloud: 21%
High level cloud: 14%
Most Significant Cloud Type: low
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 18
Nov
00:00

WNW
WNW

7 / 14 mph 41 / 36°F 78% 1016 mb
Low level cloud: 40%
Mid level cloud: 20%
High level cloud: 100%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

5 / 11 mph 39 / 35°F 76% 1017 mb
Low level cloud: 36%
Mid level cloud: 12%
High level cloud: 21%
Most Significant Cloud Type: low
42%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

3 / 6 mph 38 / 36°F 78% 1016 mb
Low level cloud: 8%
Mid level cloud: 18%
High level cloud: 19%
Most Significant Cloud Type: low
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SSE
SSE

4 / 6 mph 41 / 38°F 76% 1016 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 100%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SE
SE

9 / 10 mph 44 / 40°F 83% 1013 mb
Low level cloud: 97%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

E
E

11 / 13 mph 46 / 41°F 95% 1007 mb
Low level cloud: 100%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
18:00

NNE
NNE

15 / 17 mph 44 / 37°F 97% 1003 mb
Low level cloud: 99%
Mid level cloud: 96%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
21:00

NNE
NNE

19 / 22 mph 42 / 33°F 96% 1004 mb
Low level cloud: 99%
Mid level cloud: 55%
High level cloud: 4%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
Tue 19
Nov
00:00

NNE
NNE

20 / 23 mph 38 / 27°F 97% 1008 mb
Low level cloud: 88%
Mid level cloud: 46%
High level cloud: 11%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNW
NNW

11 / 13 mph 38 / 31°F 80% 1010 mb
Low level cloud: 21%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

7 / 12 mph 36 / 30°F 75% 1012 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
09:00

NW
NW

6 / 9 mph 38 / 33°F 66% 1014 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 0%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

7 / 10 mph 40 / 35°F 61% 1014 mb
Low level cloud: 8%
Mid level cloud: 54%
High level cloud: 0%
Most Significant Cloud Type: medium
75%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

12 / 18 mph 40 / 33°F 70% 1014 mb
Low level cloud: 1%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

9 / 14 mph 38 / 32°F 73% 1014 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: medium
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WNW
WNW

7 / 11 mph 37 / 32°F 73% 1014 mb
Low level cloud: 0%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: medium
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 20
Nov
00:00

WNW
WNW

11 / 15 mph 38 / 31°F 76% 1013 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NW
NW

13 / 22 mph 37 / 29°F 69% 1014 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

11 / 19 mph 36 / 28°F 74% 1014 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNW
NNW

11 / 16 mph 38 / 31°F 71% 1016 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
12:00

NW
NW

15 / 20 mph 41 / 33°F 62% 1016 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 3%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

20 / 24 mph 42 / 33°F 62% 1016 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 47%
Most Significant Cloud Type: medium
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

16 / 19 mph 41 / 32°F 77% 1015 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 100%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WNW
WNW

13 / 18 mph 39 / 31°F 76% 1015 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 99%
Most Significant Cloud Type: medium
34%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Thu 21
Nov
00:00

E
E

4 / 8 mph 41 / 38°F 92% 997 mb
Low level cloud: 81%
Mid level cloud: 95%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
06:00

NNW
NNW

4 / 8 mph 37 / 33°F 67% 1005 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: medium
48%
0.0 In
12:00

N
N

17 / 30 mph 37 / 28°F 86% 999 mb
Low level cloud: 87%
Mid level cloud: 15%
High level cloud: 7%
Most Significant Cloud Type: low
93%
0.0 In
18:00

WNW
WNW

17 / 29 mph 47 / 40°F 85% 995 mb
Low level cloud: 59%
Mid level cloud: 15%
High level cloud: 7%
Most Significant Cloud Type: low
65%
0.0 In
Fri 22
Nov
00:00

WNW
WNW

13 / 22 mph 40 / 33°F 73% 1005 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 0%
Most Significant Cloud Type: medium
100%
0.0 In
06:00

WNW
WNW

7 / 15 mph 29 / 22°F 87% 1014 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 45%
Most Significant Cloud Type: medium
5%
0.0 In
12:00

W
W

8 / 13 mph 43 / 38°F 77% 1011 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 36%
Most Significant Cloud Type: medium
7%
0.0 In
18:00

WNW
WNW

6 / 10 mph 42 / 38°F 70% 1017 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 28%
Most Significant Cloud Type: medium
4%
0.0 In
Sat 23
Nov
00:00

WNW
WNW

5 / 9 mph 39 / 35°F 80% 1022 mb
Low level cloud: 10%
Mid level cloud: 1%
High level cloud: 100%
Most Significant Cloud Type: medium
33%
0.0 In
06:00

NNE
NNE

3 / 5 mph 38 / 36°F 71% 1017 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

SSW
SSW

23 / 38 mph 49 / 41°F 81% 1016 mb
Low level cloud: 92%
Mid level cloud: 70%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

ENE
ENE

17 / 27 mph 40 / 31°F 95% 1010 mb
Low level cloud: 70%
Mid level cloud: 87%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
Sun 24
Nov
00:00

SW
SW

19 / 38 mph 50 / 44°F 91% 1013 mb
Low level cloud: 92%
Mid level cloud: 5%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
06:00

NNE
NNE

14 / 23 mph 30 / 19°F 85% 1012 mb
Low level cloud: 0%
Mid level cloud: 42%
High level cloud: 100%
Most Significant Cloud Type: medium
46%
0.1 In
12:00

SSW
SSW

14 / 25 mph 54 / 49°F 93% 1013 mb
Low level cloud: 97%
Mid level cloud: 16%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NNE
NNE

14 / 22 mph 34 / 25°F 80% 1015 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 100%
Most Significant Cloud Type: medium
8%
0.0 In
Mon 25
Nov
00:00

S
S

13 / 23 mph 55 / 52°F 94% 1012 mb
Low level cloud: 96%
Mid level cloud: 30%
High level cloud: 19%
Most Significant Cloud Type: low
100%
0.0 In
06:00

NNW
NNW

6 / 12 mph 32 / 26°F 77% 1018 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
12:00

S
S

19 / 32 mph 59 / 59°F 88% 1004 mb
Low level cloud: 42%
Mid level cloud: 88%
High level cloud: 99%
Most Significant Cloud Type: low
85%
0.1 In
18:00

NW
NW

7 / 11 mph 37 / 32°F 80% 1018 mb
Low level cloud: 0%
Mid level cloud: 93%
High level cloud: 0%
Most Significant Cloud Type: medium
93%
0.0 In
Tue 26
Nov
00:00

SSW
SSW

23 / 45 mph 54 / 48°F 84% 1002 mb
Low level cloud: 42%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: low
49%
0.0 In
06:00

WNW
WNW

8 / 13 mph 38 / 32°F 87% 1014 mb
Low level cloud: 2%
Mid level cloud: 31%
High level cloud: 3%
Most Significant Cloud Type: medium
35%
0.0 In
12:00

SSW
SSW

22 / 39 mph 56 / 52°F 83% 1002 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 4%
Most Significant Cloud Type: medium
8%
0.0 In
18:00

NW
NW

9 / 18 mph 34 / 27°F 79% 1017 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: medium
43%
0.0 In
Wed 27
Nov
00:00

WSW
WSW

15 / 27 mph 51 / 46°F 86% 1010 mb
Low level cloud: 37%
Mid level cloud: 6%
High level cloud: 100%
Most Significant Cloud Type: low
50%
0.0 In
06:00

NNW
NNW

9 / 18 mph 32 / 24°F 71% 1022 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
0.0 In
12:00

S
S

13 / 24 mph 55 / 51°F 94% 1011 mb
Low level cloud: 76%
Mid level cloud: 9%
High level cloud: 33%
Most Significant Cloud Type: low
83%
0.0 In
18:00

NNE
NNE

12 / 21 mph 35 / 26°F 76% 1027 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Thu 28
Nov
00:00

WSW
WSW

21 / 41 mph 55 / 50°F 88% 1003 mb
Low level cloud: 38%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: low
45%
0.3 In
06:00

NE
NE

12 / 22 mph 30 / 20°F 88% 1029 mb
Low level cloud: 2%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
1%
0.0 In
12:00

SW
SW

18 / 35 mph 51 / 46°F 81% 1006 mb
Low level cloud: 35%
Mid level cloud: 36%
High level cloud: 0%
Most Significant Cloud Type: low
47%
0.0 In
18:00

NE
NE

14 / 23 mph 36 / 27°F 90% 1030 mb
Low level cloud: 11%
Mid level cloud: 0%
High level cloud: 100%
Most Significant Cloud Type: medium
33%
0.0 In
Fri 29
Nov
00:00

WSW
WSW

23 / 48 mph 48 / 41°F 77% 1005 mb
Low level cloud: 37%
Mid level cloud: 15%
High level cloud: 19%
Most Significant Cloud Type: low
44%
0.3 In
06:00

ENE
ENE

16 / 26 mph 35 / 25°F 88% 1026 mb
Low level cloud: 7%
Mid level cloud: 59%
High level cloud: 100%
Most Significant Cloud Type: medium
82%
0.0 In
12:00

WSW
WSW

20 / 42 mph 50 / 44°F 79% 1006 mb
Low level cloud: 24%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: low
32%
0.1 In
18:00

E
E

18 / 30 mph 42 / 34°F 77% 1022 mb
Low level cloud: 0%
Mid level cloud: 74%
High level cloud: 100%
Most Significant Cloud Type: medium
77%
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