WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Achddu 14 Day Long Range Forecast

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

Carmarthenshire, United Kingdom

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

Taking a look at Achddu over the coming two weeks and the average daytime maximum temperature will be around 16°C, with a high for the two weeks of 19°C expected on the evening of Friday 24th. The mean minimum temperature will be 11°C, dipping to its lowest on the morning of Tuesday 21st at 8°C. Expect the next 14 days have some days seeing a little precipitation and some days with rain. The current forecast indicates Wednesday 22nd will have the most precipitation with an accumulation of around 18.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Wed 15
May
18:00

ESE
ESE

12 / 19 mph 58 / 55°F 81% 1004 mb
Low level cloud: 10%
Mid level cloud: 26%
High level cloud: 0%
Most Significant Cloud Type: low
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

E
E

8 / 15 mph 54 / 50°F 90% 1005 mb
Low level cloud: 22%
Mid level cloud: 18%
High level cloud: 13%
Most Significant Cloud Type: low
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 16
May
00:00

E
E

9 / 16 mph 51 / 48°F 92% 1005 mb
Low level cloud: 11%
Mid level cloud: 16%
High level cloud: 13%
Most Significant Cloud Type: low
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

8 / 16 mph 50 / 47°F 91% 1005 mb
Low level cloud: 14%
Mid level cloud: 14%
High level cloud: 1%
Most Significant Cloud Type: low
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

ENE
ENE

7 / 12 mph 53 / 49°F 90% 1006 mb
Low level cloud: 21%
Mid level cloud: 12%
High level cloud: 33%
Most Significant Cloud Type: low
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

E
E

8 / 11 mph 59 / 56°F 80% 1006 mb
Low level cloud: 60%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: low
86%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ESE
ESE

6 / 9 mph 62 / 59°F 79% 1006 mb
Low level cloud: 30%
Mid level cloud: 48%
High level cloud: 100%
Most Significant Cloud Type: low
58%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ENE
ENE

3 / 5 mph 59 / 60°F 83% 1006 mb
Low level cloud: 11%
Mid level cloud: 87%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
18:00

NNE
NNE

7 / 12 mph 56 / 54°F 89% 1006 mb
Low level cloud: 18%
Mid level cloud: 61%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
21:00

N
N

6 / 9 mph 55 / 51°F 93% 1007 mb
Low level cloud: 26%
Mid level cloud: 65%
High level cloud: 88%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 17
May
00:00

NW
NW

3 / 4 mph 54 / 54°F 95% 1007 mb
Low level cloud: 55%
Mid level cloud: 71%
High level cloud: 33%
Most Significant Cloud Type: low
83%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

4 / 6 mph 53 / 52°F 96% 1007 mb
Low level cloud: 84%
Mid level cloud: 55%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

0 / 1 mph 52 / 52°F 95% 1008 mb
Low level cloud: 68%
Mid level cloud: 43%
High level cloud: 99%
Most Significant Cloud Type: low
95%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SSW
SSW

4 / 7 mph 55 / 53°F 89% 1009 mb
Low level cloud: 71%
Mid level cloud: 40%
High level cloud: 66%
Most Significant Cloud Type: low
92%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WSW
WSW

6 / 6 mph 59 / 56°F 88% 1010 mb
Low level cloud: 30%
Mid level cloud: 18%
High level cloud: 93%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

W
W

6 / 7 mph 60 / 58°F 82% 1010 mb
Low level cloud: 3%
Mid level cloud: 8%
High level cloud: 27%
Most Significant Cloud Type: medium
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

W
W

5 / 7 mph 60 / 58°F 87% 1011 mb
Low level cloud: 2%
Mid level cloud: 5%
High level cloud: 7%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

1 / 2 mph 58 / 56°F 93% 1013 mb
Low level cloud: 17%
Mid level cloud: 5%
High level cloud: 39%
Most Significant Cloud Type: low
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 18
May
00:00

NE
NE

2 / 3 mph 53 / 53°F 93% 1013 mb
Low level cloud: 22%
Mid level cloud: 6%
High level cloud: 57%
Most Significant Cloud Type: low
30%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNE
NNE

2 / 4 mph 51 / 52°F 93% 1014 mb
Low level cloud: 19%
Mid level cloud: 10%
High level cloud: 100%
Most Significant Cloud Type: low
34%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

4 / 7 mph 54 / 52°F 91% 1014 mb
Low level cloud: 11%
Mid level cloud: 9%
High level cloud: 32%
Most Significant Cloud Type: low
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

N
N

4 / 6 mph 62 / 59°F 80% 1015 mb
Low level cloud: 6%
Mid level cloud: 8%
High level cloud: 15%
Most Significant Cloud Type: low
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

4 / 6 mph 66 / 63°F 71% 1015 mb
Low level cloud: 13%
Mid level cloud: 5%
High level cloud: 11%
Most Significant Cloud Type: low
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNW
NNW

9 / 13 mph 65 / 63°F 80% 1015 mb
Low level cloud: 33%
Mid level cloud: 10%
High level cloud: 5%
Most Significant Cloud Type: low
37%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNW
NNW

12 / 18 mph 61 / 60°F 87% 1015 mb
Low level cloud: 6%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: medium
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

N
N

8 / 16 mph 56 / 52°F 92% 1016 mb
Low level cloud: 9%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
71%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 19
May
00:00

NNE
NNE

6 / 13 mph 53 / 51°F 94% 1016 mb
Low level cloud: 4%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

N
N

6 / 12 mph 51 / 49°F 93% 1016 mb
Low level cloud: 5%
Mid level cloud: 22%
High level cloud: 2%
Most Significant Cloud Type: medium
37%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

6 / 11 mph 54 / 50°F 92% 1017 mb
Low level cloud: 42%
Mid level cloud: 15%
High level cloud: 3%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

8 / 11 mph 60 / 58°F 77% 1017 mb
Low level cloud: 36%
Mid level cloud: 7%
High level cloud: 6%
Most Significant Cloud Type: low
39%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ENE
ENE

5 / 7 mph 61 / 60°F 74% 1017 mb
Low level cloud: 85%
Mid level cloud: 15%
High level cloud: 1%
Most Significant Cloud Type: low
90%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

E
E

4 / 6 mph 64 / 61°F 75% 1017 mb
Low level cloud: 66%
Mid level cloud: 21%
High level cloud: 11%
Most Significant Cloud Type: low
74%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

4 / 7 mph 63 / 60°F 83% 1017 mb
Low level cloud: 21%
Mid level cloud: 25%
High level cloud: 95%
Most Significant Cloud Type: low
41%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

7 / 13 mph 56 / 53°F 88% 1019 mb
Low level cloud: 8%
Mid level cloud: 4%
High level cloud: 63%
Most Significant Cloud Type: low
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 20
May
00:00

NE
NE

8 / 14 mph 51 / 48°F 89% 1019 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 43%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

7 / 12 mph 49 / 46°F 90% 1019 mb
Low level cloud: 2%
Mid level cloud: 9%
High level cloud: 56%
Most Significant Cloud Type: medium
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

ENE
ENE

6 / 9 mph 50 / 46°F 88% 1019 mb
Low level cloud: 7%
Mid level cloud: 21%
High level cloud: 33%
Most Significant Cloud Type: medium
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

E
E

8 / 9 mph 55 / 51°F 80% 1020 mb
Low level cloud: 56%
Mid level cloud: 44%
High level cloud: 12%
Most Significant Cloud Type: low
72%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ESE
ESE

4 / 4 mph 59 / 58°F 71% 1019 mb
Low level cloud: 74%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
81%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

3 / 4 mph 58 / 56°F 79% 1018 mb
Low level cloud: 67%
Mid level cloud: 13%
High level cloud: 1%
Most Significant Cloud Type: low
72%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

2 / 4 mph 56 / 57°F 79% 1017 mb
Low level cloud: 90%
Mid level cloud: 13%
High level cloud: 5%
Most Significant Cloud Type: low
95%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNE
NNE

1 / 2 mph 57 / 55°F 80% 1017 mb
Low level cloud: 57%
Mid level cloud: 7%
High level cloud: 6%
Most Significant Cloud Type: low
60%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 21
May
00:00

ENE
ENE

5 / 11 mph 51 / 49°F 85% 1017 mb
Low level cloud: 17%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: low
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

6 / 12 mph 48 / 46°F 87% 1016 mb
Low level cloud: 1%
Mid level cloud: 0%
High level cloud: 17%
Most Significant Cloud Type: high
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

E
E

6 / 10 mph 50 / 46°F 85% 1015 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 4%
Most Significant Cloud Type: medium
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ESE
ESE

7 / 8 mph 55 / 52°F 74% 1015 mb
Low level cloud: 0%
Mid level cloud: 97%
High level cloud: 49%
Most Significant Cloud Type: medium
99%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SSE
SSE

5 / 7 mph 60 / 57°F 67% 1014 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 34%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

4 / 6 mph 60 / 58°F 69% 1014 mb
Low level cloud: 1%
Mid level cloud: 61%
High level cloud: 11%
Most Significant Cloud Type: medium
65%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

4 / 5 mph 59 / 58°F 75% 1013 mb
Low level cloud: 10%
Mid level cloud: 27%
High level cloud: 5%
Most Significant Cloud Type: low
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNW
NNW

6 / 12 mph 54 / 50°F 85% 1014 mb
Low level cloud: 0%
Mid level cloud: 28%
High level cloud: 2%
Most Significant Cloud Type: medium
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Wed 22
May
00:00

WSW
WSW

6 / 13 mph 54 / 52°F 95% 1010 mb
Low level cloud: 53%
Mid level cloud: 45%
High level cloud: 94%
Most Significant Cloud Type: low
80%
0.0 In
06:00

SE
SE

5 / 11 mph 53 / 51°F 95% 1012 mb
Low level cloud: 88%
Mid level cloud: 44%
High level cloud: 88%
Most Significant Cloud Type: low
100%
0.0 In
12:00

N
N

6 / 13 mph 59 / 58°F 84% 1012 mb
Low level cloud: 89%
Mid level cloud: 27%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NNW
NNW

9 / 18 mph 58 / 56°F 87% 1013 mb
Low level cloud: 54%
Mid level cloud: 23%
High level cloud: 7%
Most Significant Cloud Type: low
63%
0.0 In
Thu 23
May
00:00

NE
NE

5 / 11 mph 53 / 52°F 92% 1014 mb
Low level cloud: 32%
Mid level cloud: 43%
High level cloud: 33%
Most Significant Cloud Type: low
50%
0.0 In
06:00

SSE
SSE

11 / 23 mph 51 / 47°F 91% 1019 mb
Low level cloud: 16%
Mid level cloud: 5%
High level cloud: 32%
Most Significant Cloud Type: low
21%
0.0 In
12:00

N
N

13 / 28 mph 59 / 59°F 73% 1023 mb
Low level cloud: 77%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: low
85%
0.0 In
18:00

NNE
NNE

10 / 21 mph 62 / 62°F 87% 1017 mb
Low level cloud: 73%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: low
88%
0.0 In
Fri 24
May
00:00

NNE
NNE

10 / 21 mph 54 / 51°F 84% 1021 mb
Low level cloud: 75%
Mid level cloud: 48%
High level cloud: 0%
Most Significant Cloud Type: low
91%
0.1 In
06:00

NE
NE

7 / 15 mph 52 / 49°F 89% 1019 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
12:00

E
E

10 / 21 mph 58 / 56°F 91% 1021 mb
Low level cloud: 96%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NW
NW

2 / 4 mph 66 / 66°F 79% 1018 mb
Low level cloud: 31%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
31%
0.0 In
Sat 25
May
00:00

ESE
ESE

7 / 15 mph 51 / 49°F 92% 1020 mb
Low level cloud: 5%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
7%
0.0 In
06:00

NE
NE

3 / 6 mph 58 / 59°F 91% 1020 mb
Low level cloud: 9%
Mid level cloud: 0%
High level cloud: 5%
Most Significant Cloud Type: low
9%
0.0 In
12:00

SSW
SSW

9 / 18 mph 56 / 53°F 90% 1019 mb
Low level cloud: 97%
Mid level cloud: 32%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

WNW
WNW

8 / 16 mph 62 / 62°F 85% 1018 mb
Low level cloud: 3%
Mid level cloud: 3%
High level cloud: 6%
Most Significant Cloud Type: low
4%
0.0 In
Sun 26
May
00:00

NE
NE

3 / 7 mph 55 / 55°F 89% 1019 mb
Low level cloud: 33%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
61%
0.0 In
06:00

N
N

5 / 10 mph 56 / 56°F 86% 1018 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: medium
2%
0.0 In
12:00

W
W

1 / 2 mph 64 / 64°F 76% 1018 mb
Low level cloud: 38%
Mid level cloud: 43%
High level cloud: 31%
Most Significant Cloud Type: low
56%
0.0 In
18:00

NNW
NNW

12 / 25 mph 56 / 54°F 78% 1019 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 3%
Most Significant Cloud Type: medium
4%
0.0 In
Mon 27
May
00:00

ENE
ENE

12 / 26 mph 59 / 59°F 92% 1017 mb
Low level cloud: 13%
Mid level cloud: 8%
High level cloud: 5%
Most Significant Cloud Type: low
16%
0.3 In
06:00

NNW
NNW

6 / 13 mph 53 / 51°F 81% 1021 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 58%
Most Significant Cloud Type: medium
9%
0.0 In
12:00

ENE
ENE

13 / 28 mph 62 / 62°F 66% 1019 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: medium
10%
0.0 In
18:00

NW
NW

8 / 17 mph 57 / 55°F 76% 1021 mb
Low level cloud: 16%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
20%
0.0 In
Tue 28
May
00:00

N
N

7 / 15 mph 49 / 46°F 88% 1015 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
06:00

NNW
NNW

12 / 26 mph 48 / 43°F 86% 1023 mb
Low level cloud: 7%
Mid level cloud: 3%
High level cloud: 13%
Most Significant Cloud Type: low
10%
0.0 In
12:00

NNE
NNE

12 / 24 mph 55 / 52°F 80% 1007 mb
Low level cloud: 7%
Mid level cloud: 60%
High level cloud: 46%
Most Significant Cloud Type: medium
81%
0.0 In
18:00

NW
NW

8 / 17 mph 55 / 53°F 73% 1023 mb
Low level cloud: 0%
Mid level cloud: 86%
High level cloud: 32%
Most Significant Cloud Type: medium
87%
0.0 In
Wed 29
May
00:00

NE
NE

8 / 17 mph 54 / 52°F 90% 1006 mb
Low level cloud: 71%
Mid level cloud: 46%
High level cloud: 98%
Most Significant Cloud Type: low
99%
0.0 In
06:00

WNW
WNW

7 / 14 mph 50 / 47°F 85% 1021 mb
Low level cloud: 1%
Mid level cloud: 3%
High level cloud: 13%
Most Significant Cloud Type: medium
4%
0.0 In
12:00

NNE
NNE

3 / 6 mph 59 / 60°F 96% 1006 mb
Low level cloud: 93%
Mid level cloud: 79%
High level cloud: 59%
Most Significant Cloud Type: low
100%
0.1 In
18:00

WSW
WSW

13 / 28 mph 57 / 54°F 82% 1018 mb
Low level cloud: 10%
Mid level cloud: 44%
High level cloud: 19%
Most Significant Cloud Type: medium
73%
0.0 In
Thu 30
May
00:00

ESE
ESE

3 / 7 mph 62 / 62°F 93% 1007 mb
Low level cloud: 13%
Mid level cloud: 30%
High level cloud: 9%
Most Significant Cloud Type: low
24%
0.0 In
06:00

W
W

8 / 17 mph 54 / 51°F 94% 1015 mb
Low level cloud: 85%
Mid level cloud: 74%
High level cloud: 4%
Most Significant Cloud Type: low
100%
0.0 In
12:00

SSW
SSW

6 / 13 mph 61 / 61°F 75% 1007 mb
Low level cloud: 2%
Mid level cloud: 29%
High level cloud: 20%
Most Significant Cloud Type: medium
34%
0.0 In
18:00

WSW
WSW

11 / 22 mph 58 / 56°F 85% 1015 mb
Low level cloud: 18%
Mid level cloud: 9%
High level cloud: 13%
Most Significant Cloud Type: low
22%
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