Weather2 on Twitter Weather2 on Facebook Weather2 on YouTube Weather2 blog

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Fagwyr 14 Day Long Range Forecast

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

Abertawe, United Kingdom

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

For Fagwyr in the coming two weeks the average daytime maximum temperature will be around 12°C, with a high for the two weeks of 15°C expected on the afternoon of Friday 29th. The mean minimum temperature will be 5°C, dipping to its lowest on the morning of Tuesday 2nd at 3°C. Expect the next 14 days remain predominantly dry. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sat 23
Mar
18:00

ENE
ENE

5 / 6 mph 52 / 49°F 72% 1033 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 100%
Most Significant Cloud Type: medium
28%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

NE
NE

6 / 7 mph 49 / 46°F 74% 1034 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: medium
48%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Sun 24
Mar
00:00

ENE
ENE

5 / 8 mph 46 / 43°F 74% 1034 mb
Low level cloud: 0%
Mid level cloud: 85%
High level cloud: 87%
Most Significant Cloud Type: medium
88%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
03:00

NNE
NNE

2 / 4 mph 44 / 44°F 77% 1033 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 90%
Most Significant Cloud Type: medium
17%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

N
N

5 / 7 mph 43 / 40°F 85% 1033 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

NNW
NNW

8 / 10 mph 46 / 41°F 71% 1034 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

NW
NW

11 / 12 mph 50 / 45°F 64% 1034 mb
Low level cloud: 11%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
11%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

NW
NW

13 / 15 mph 50 / 44°F 62% 1034 mb
Low level cloud: 0%
Mid level cloud: 1%
High level cloud: 5%
Most Significant Cloud Type: high
4%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

NW
NW

10 / 13 mph 47 / 42°F 74% 1033 mb
Low level cloud: 2%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
4%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

NW
NW

8 / 15 mph 43 / 38°F 82% 1034 mb
Low level cloud: 25%
Mid level cloud: 4%
High level cloud: 13%
Most Significant Cloud Type: low
27%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Mon 25
Mar
00:00

NW
NW

9 / 16 mph 43 / 38°F 87% 1034 mb
Low level cloud: 8%
Mid level cloud: 11%
High level cloud: 93%
Most Significant Cloud Type: medium
38%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

NNW
NNW

12 / 19 mph 43 / 37°F 88% 1034 mb
Low level cloud: 22%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
24%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

NNW
NNW

12 / 19 mph 43 / 37°F 89% 1035 mb
Low level cloud: 11%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
13%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

N
N

13 / 17 mph 47 / 41°F 75% 1036 mb
Low level cloud: 40%
Mid level cloud: 5%
High level cloud: 4%
Most Significant Cloud Type: low
42%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

N
N

8 / 11 mph 50 / 46°F 62% 1036 mb
Low level cloud: 41%
Mid level cloud: 3%
High level cloud: 9%
Most Significant Cloud Type: low
42%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

N
N

4 / 6 mph 52 / 50°F 57% 1036 mb
Low level cloud: 13%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
15%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

NNW
NNW

6 / 9 mph 49 / 46°F 72% 1036 mb
Low level cloud: 26%
Mid level cloud: 9%
High level cloud: 2%
Most Significant Cloud Type: low
29%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

N
N

7 / 11 mph 45 / 41°F 84% 1038 mb
Low level cloud: 6%
Mid level cloud: 9%
High level cloud: 1%
Most Significant Cloud Type: low
9%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Tue 26
Mar
00:00

NE
NE

5 / 9 mph 43 / 40°F 81% 1038 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: medium
7%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

E
E

4 / 7 mph 41 / 38°F 83% 1038 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 8%
Most Significant Cloud Type: medium
6%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

SSE
SSE

2 / 4 mph 40 / 40°F 85% 1037 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

WSW
WSW

2 / 2 mph 48 / 48°F 74% 1038 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: medium
2%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

WSW
WSW

6 / 8 mph 52 / 49°F 65% 1038 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 3%
Most Significant Cloud Type: high
2%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

W
W

9 / 10 mph 53 / 50°F 66% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

W
W

8 / 9 mph 53 / 50°F 80% 1036 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

NNW
NNW

6 / 7 mph 48 / 46°F 87% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Wed 27
Mar
00:00

N
N

4 / 8 mph 43 / 40°F 84% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

NNW
NNW

3 / 7 mph 40 / 38°F 82% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

N
N

4 / 8 mph 40 / 37°F 84% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

NNW
NNW

4 / 5 mph 49 / 47°F 77% 1038 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

WNW
WNW

6 / 8 mph 55 / 53°F 70% 1038 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
2%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

WNW
WNW

8 / 11 mph 56 / 53°F 71% 1037 mb
Low level cloud: 2%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
2%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

NNW
NNW

7 / 8 mph 55 / 53°F 80% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

N
N

7 / 14 mph 44 / 40°F 79% 1038 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 13%
Most Significant Cloud Type: high
12%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Thu 28
Mar
00:00

NE
NE

6 / 13 mph 43 / 39°F 83% 1038 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 8%
Most Significant Cloud Type: high
8%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

ENE
ENE

4 / 9 mph 41 / 38°F 88% 1037 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 10%
Most Significant Cloud Type: high
9%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

E
E

4 / 9 mph 41 / 38°F 89% 1036 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 3%
Most Significant Cloud Type: low
3%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

SE
SE

4 / 4 mph 51 / 49°F 78% 1036 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: high
1%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

S
S

4 / 5 mph 56 / 55°F 68% 1036 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

SW
SW

3 / 4 mph 58 / 58°F 69% 1033 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

WSW
WSW

2 / 3 mph 58 / 58°F 80% 1032 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

SSE
SSE

1 / 1 mph 52 / 52°F 85% 1032 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Fri 29
Mar
00:00

SSE
SSE

3 / 6 mph 45 / 44°F 84% 1032 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

S
S

3 / 6 mph 44 / 42°F 89% 1030 mb
Low level cloud: 30%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
29%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

S
S

4 / 8 mph 43 / 41°F 92% 1030 mb
Low level cloud: 26%
Mid level cloud: 0%
High level cloud: 21%
Most Significant Cloud Type: low
28%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

S
S

6 / 6 mph 53 / 51°F 81% 1029 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 60%
Most Significant Cloud Type: medium
10%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

SSW
SSW

6 / 7 mph 58 / 56°F 67% 1028 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 17%
Most Significant Cloud Type: high
16%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

SW
SW

5 / 6 mph 59 / 57°F 66% 1026 mb
Low level cloud: 0%
Mid level cloud: 1%
High level cloud: 0%
Most Significant Cloud Type: medium
1%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

WSW
WSW

3 / 3 mph 55 / 54°F 79% 1025 mb
Low level cloud: 14%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
15%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

SSW
SSW

2 / 5 mph 46 / 46°F 88% 1026 mb
Low level cloud: 74%
Mid level cloud: 2%
High level cloud: 7%
Most Significant Cloud Type: low
75%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sat 30
Mar
00:00

WSW
WSW

4 / 6 mph 49 / 48°F 92% 1023 mb
Low level cloud: 20%
Mid level cloud: 47%
High level cloud: 18%
Most Significant Cloud Type: low
38%
0.00 In
06:00

SSE
SSE

5 / 9 mph 49 / 47°F 92% 1015 mb
Low level cloud: 10%
Mid level cloud: 59%
High level cloud: 5%
Most Significant Cloud Type: medium
86%
0.01 In
12:00

SSE
SSE

19 / 23 mph 59 / 59°F 65% 1017 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
0.00 In
18:00

NNW
NNW

12 / 14 mph 53 / 49°F 89% 1018 mb
Low level cloud: 46%
Mid level cloud: 4%
High level cloud: 76%
Most Significant Cloud Type: low
57%
0.01 In
Sun 31
Mar
00:00

S
S

11 / 15 mph 50 / 46°F 94% 1016 mb
Low level cloud: 56%
Mid level cloud: 3%
High level cloud: 61%
Most Significant Cloud Type: low
64%
0.00 In
06:00

SSE
SSE

9 / 12 mph 50 / 46°F 94% 1018 mb
Low level cloud: 48%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: low
63%
0.06 In
12:00

WNW
WNW

6 / 7 mph 52 / 50°F 94% 1017 mb
Low level cloud: 91%
Mid level cloud: 60%
High level cloud: 89%
Most Significant Cloud Type: low
100%
0.03 In
18:00

W
W

5 / 6 mph 56 / 55°F 84% 1019 mb
Low level cloud: 2%
Mid level cloud: 30%
High level cloud: 21%
Most Significant Cloud Type: medium
36%
0.00 In
Mon 01
Apr
00:00

N
N

9 / 15 mph 40 / 34°F 81% 1018 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
0.00 In
06:00

NNE
NNE

3 / 4 mph 52 / 52°F 94% 1023 mb
Low level cloud: 64%
Mid level cloud: 11%
High level cloud: 9%
Most Significant Cloud Type: low
69%
0.00 In
12:00

NNE
NNE

9 / 13 mph 49 / 46°F 62% 1023 mb
Low level cloud: 60%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
63%
0.00 In
18:00

ENE
ENE

4 / 6 mph 56 / 56°F 80% 1025 mb
Low level cloud: 29%
Mid level cloud: 1%
High level cloud: 3%
Most Significant Cloud Type: low
30%
0.00 In
Tue 02
Apr
00:00

E
E

11 / 19 mph 39 / 33°F 88% 1027 mb
Low level cloud: 2%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
3%
0.00 In
06:00

ESE
ESE

13 / 19 mph 47 / 41°F 94% 1026 mb
Low level cloud: 58%
Mid level cloud: 1%
High level cloud: 1%
Most Significant Cloud Type: low
58%
0.00 In
12:00

ESE
ESE

7 / 8 mph 51 / 49°F 59% 1028 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.00 In
18:00

ESE
ESE

15 / 21 mph 55 / 51°F 76% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 21%
Most Significant Cloud Type: high
21%
0.00 In
Wed 03
Apr
00:00

ENE
ENE

9 / 19 mph 41 / 35°F 87% 1027 mb
Low level cloud: 4%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
3%
0.00 In
06:00

E
E

16 / 31 mph 42 / 35°F 88% 1016 mb
Low level cloud: 11%
Mid level cloud: 7%
High level cloud: 33%
Most Significant Cloud Type: low
17%
0.00 In
12:00

E
E

15 / 17 mph 53 / 48°F 68% 1023 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: high
1%
0.00 In
18:00

ESE
ESE

17 / 20 mph 59 / 59°F 80% 1006 mb
Low level cloud: 14%
Mid level cloud: 53%
High level cloud: 38%
Most Significant Cloud Type: medium
93%
0.00 In
Thu 04
Apr
00:00

ENE
ENE

13 / 22 mph 44 / 37°F 91% 1019 mb
Low level cloud: 18%
Mid level cloud: 2%
High level cloud: 14%
Most Significant Cloud Type: low
20%
0.00 In
06:00

S
S

19 / 35 mph 48 / 42°F 90% 1001 mb
Low level cloud: 62%
Mid level cloud: 14%
High level cloud: 1%
Most Significant Cloud Type: low
66%
0.24 In
12:00

ENE
ENE

11 / 14 mph 52 / 48°F 86% 1015 mb
Low level cloud: 69%
Mid level cloud: 43%
High level cloud: 38%
Most Significant Cloud Type: low
89%
0.04 In
18:00

SW
SW

8 / 15 mph 51 / 48°F 80% 1009 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 14%
Most Significant Cloud Type: medium
4%
0.02 In
Fri 05
Apr
00:00

NNE
NNE

6 / 11 mph 48 / 46°F 95% 1014 mb
Low level cloud: 42%
Mid level cloud: 25%
High level cloud: 32%
Most Significant Cloud Type: low
54%
0.11 In
06:00

ESE
ESE

14 / 29 mph 45 / 38°F 92% 1009 mb
Low level cloud: 23%
Mid level cloud: 46%
High level cloud: 39%
Most Significant Cloud Type: low
43%
0.00 In
12:00

NE
NE

5 / 6 mph 54 / 53°F 83% 1015 mb
Low level cloud: 70%
Mid level cloud: 46%
High level cloud: 6%
Most Significant Cloud Type: low
86%
0.01 In
18:00

SSW
SSW

15 / 22 mph 52 / 47°F 91% 1001 mb
Low level cloud: 59%
Mid level cloud: 43%
High level cloud: 51%
Most Significant Cloud Type: low
80%
0.15 In
Sat 06
Apr
00:00

NW
NW

6 / 9 mph 48 / 45°F 94% 1014 mb
Low level cloud: 49%
Mid level cloud: 15%
High level cloud: 8%
Most Significant Cloud Type: low
55%
0.01 In
06:00

SSE
SSE

15 / 23 mph 49 / 44°F 92% 1000 mb
Low level cloud: 29%
Mid level cloud: 59%
High level cloud: 61%
Most Significant Cloud Type: low
57%
0.01 In
12:00

WSW
WSW

5 / 6 mph 53 / 52°F 82% 1016 mb
Low level cloud: 78%
Mid level cloud: 10%
High level cloud: 10%
Most Significant Cloud Type: low
83%
0.01 In
18:00

WNW
WNW

15 / 28 mph 46 / 40°F 74% 1010 mb
Low level cloud: 52%
Mid level cloud: 41%
High level cloud: 33%
Most Significant Cloud Type: low
70%
0.20 In
Sun 07
Apr
00:00

ENE
ENE

3 / 4 mph 50 / 50°F 91% 1017 mb
Low level cloud: 17%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
19%
0.00 In
06:00

SSW
SSW

16 / 23 mph 43 / 35°F 84% 1012 mb
Low level cloud: 56%
Mid level cloud: 47%
High level cloud: 0%
Most Significant Cloud Type: low
72%
0.07 In
12:00

ESE
ESE

11 / 13 mph 58 / 55°F 73% 1018 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 18%
Most Significant Cloud Type: high
18%
0.00 In
18:00

W
W

15 / 26 mph 44 / 37°F 71% 1016 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
0.15 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