WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Dulas 14 Day Long Range Forecast

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

Isle of Anglesey, United Kingdom

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

Taking a look at Dulas over the coming two weeks and the average daytime maximum temperature will be around 14°C, with a high for the two weeks of 17°C expected on the afternoon of Sunday 2nd. The mean minimum temperature will be 9°C, dipping to its lowest on the morning of Wednesday 5th at 6°C. The fortnight ahead will have some days seeing a little precipitation and some days with rain. Predictions are Thursday 6th will have the most precipitation with an accumulation of around 6.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sun 02
Jun
18:00

W
W

7 / 10 mph 59 / 58°F 79% 1028 mb
Low level cloud: 84%
Mid level cloud: 29%
High level cloud: 13%
Most Significant Cloud Type: low
95%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SW
SW

6 / 7 mph 57 / 56°F 87% 1027 mb
Low level cloud: 95%
Mid level cloud: 21%
High level cloud: 40%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 03
Jun
00:00

W
W

4 / 8 mph 55 / 55°F 92% 1026 mb
Low level cloud: 88%
Mid level cloud: 18%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

7 / 11 mph 54 / 52°F 94% 1025 mb
Low level cloud: 98%
Mid level cloud: 7%
High level cloud: 92%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WNW
WNW

7 / 11 mph 53 / 51°F 91% 1024 mb
Low level cloud: 100%
Mid level cloud: 51%
High level cloud: 33%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NW
NW

9 / 12 mph 55 / 53°F 89% 1024 mb
Low level cloud: 91%
Mid level cloud: 32%
High level cloud: 90%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WNW
WNW

9 / 11 mph 58 / 56°F 87% 1023 mb
Low level cloud: 98%
Mid level cloud: 21%
High level cloud: 88%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

W
W

8 / 9 mph 59 / 57°F 85% 1022 mb
Low level cloud: 88%
Mid level cloud: 7%
High level cloud: 93%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

8 / 10 mph 58 / 56°F 88% 1021 mb
Low level cloud: 78%
Mid level cloud: 2%
High level cloud: 4%
Most Significant Cloud Type: low
79%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SSW
SSW

9 / 13 mph 56 / 53°F 94% 1019 mb
Low level cloud: 90%
Mid level cloud: 2%
High level cloud: 4%
Most Significant Cloud Type: low
91%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 04
Jun
00:00

SSW
SSW

10 / 15 mph 54 / 51°F 96% 1017 mb
Low level cloud: 93%
Mid level cloud: 26%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WSW
WSW

10 / 15 mph 54 / 51°F 96% 1013 mb
Low level cloud: 97%
Mid level cloud: 50%
High level cloud: 2%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SW
SW

15 / 22 mph 53 / 48°F 97% 1011 mb
Low level cloud: 99%
Mid level cloud: 93%
High level cloud: 1%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

19 / 26 mph 54 / 49°F 93% 1009 mb
Low level cloud: 68%
Mid level cloud: 63%
High level cloud: 3%
Most Significant Cloud Type: low
90%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WSW
WSW

21 / 31 mph 53 / 47°F 94% 1008 mb
Low level cloud: 99%
Mid level cloud: 44%
High level cloud: 2%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

16 / 22 mph 54 / 49°F 76% 1008 mb
Low level cloud: 55%
Mid level cloud: 82%
High level cloud: 3%
Most Significant Cloud Type: low
84%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

14 / 20 mph 54 / 49°F 65% 1009 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 0%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WNW
WNW

9 / 18 mph 48 / 42°F 73% 1011 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 05
Jun
00:00

WNW
WNW

8 / 14 mph 46 / 42°F 85% 1012 mb
Low level cloud: 1%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

9 / 18 mph 43 / 38°F 85% 1013 mb
Low level cloud: 12%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

W
W

13 / 19 mph 47 / 41°F 82% 1014 mb
Low level cloud: 2%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

W
W

16 / 19 mph 51 / 45°F 68% 1014 mb
Low level cloud: 2%
Mid level cloud: 23%
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

WSW
WSW

17 / 19 mph 54 / 49°F 60% 1015 mb
Low level cloud: 20%
Mid level cloud: 45%
High level cloud: 0%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WSW
WSW

14 / 19 mph 54 / 49°F 63% 1015 mb
Low level cloud: 52%
Mid level cloud: 44%
High level cloud: 18%
Most Significant Cloud Type: low
69%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

11 / 17 mph 53 / 48°F 75% 1015 mb
Low level cloud: 21%
Mid level cloud: 45%
High level cloud: 47%
Most Significant Cloud Type: low
42%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

9 / 17 mph 48 / 44°F 85% 1016 mb
Low level cloud: 13%
Mid level cloud: 46%
High level cloud: 5%
Most Significant Cloud Type: medium
83%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 06
Jun
00:00

W
W

7 / 14 mph 46 / 42°F 86% 1016 mb
Low level cloud: 4%
Mid level cloud: 35%
High level cloud: 87%
Most Significant Cloud Type: medium
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

6 / 12 mph 45 / 42°F 83% 1016 mb
Low level cloud: 2%
Mid level cloud: 25%
High level cloud: 56%
Most Significant Cloud Type: medium
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SW
SW

6 / 9 mph 48 / 45°F 81% 1016 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 7%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

13 / 16 mph 52 / 48°F 67% 1015 mb
Low level cloud: 11%
Mid level cloud: 100%
High level cloud: 12%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SW
SW

17 / 21 mph 53 / 48°F 68% 1014 mb
Low level cloud: 20%
Mid level cloud: 100%
High level cloud: 2%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SW
SW

19 / 28 mph 51 / 45°F 80% 1012 mb
Low level cloud: 90%
Mid level cloud: 62%
High level cloud: 11%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSW
SSW

21 / 31 mph 50 / 43°F 94% 1009 mb
Low level cloud: 96%
Mid level cloud: 78%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
21:00

SW
SW

20 / 30 mph 52 / 46°F 95% 1009 mb
Low level cloud: 84%
Mid level cloud: 46%
High level cloud: 2%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
Fri 07
Jun
00:00

W
W

16 / 26 mph 50 / 45°F 92% 1009 mb
Low level cloud: 65%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: low
73%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

13 / 23 mph 47 / 41°F 86% 1009 mb
Low level cloud: 3%
Mid level cloud: 4%
High level cloud: 1%
Most Significant Cloud Type: low
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WSW
WSW

17 / 26 mph 49 / 43°F 79% 1009 mb
Low level cloud: 28%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WSW
WSW

20 / 27 mph 52 / 45°F 79% 1010 mb
Low level cloud: 33%
Mid level cloud: 47%
High level cloud: 0%
Most Significant Cloud Type: low
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

20 / 28 mph 52 / 45°F 83% 1011 mb
Low level cloud: 42%
Mid level cloud: 46%
High level cloud: 15%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

15 / 19 mph 55 / 50°F 67% 1012 mb
Low level cloud: 2%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

9 / 13 mph 55 / 51°F 72% 1013 mb
Low level cloud: 5%
Mid level cloud: 19%
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

W
W

9 / 19 mph 47 / 42°F 84% 1014 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
Sat 08
Jun
00:00

W
W

14 / 25 mph 47 / 41°F 85% 1015 mb
Low level cloud: 3%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

17 / 28 mph 47 / 40°F 89% 1015 mb
Low level cloud: 4%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WNW
WNW

18 / 28 mph 48 / 41°F 87% 1016 mb
Low level cloud: 75%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
81%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WNW
WNW

20 / 27 mph 50 / 44°F 75% 1017 mb
Low level cloud: 89%
Mid level cloud: 17%
High level cloud: 14%
Most Significant Cloud Type: low
97%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WNW
WNW

21 / 28 mph 54 / 48°F 76% 1018 mb
Low level cloud: 43%
Mid level cloud: 46%
High level cloud: 4%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WNW
WNW

19 / 26 mph 56 / 51°F 75% 1019 mb
Low level cloud: 43%
Mid level cloud: 46%
High level cloud: 32%
Most Significant Cloud Type: low
62%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NW
NW

14 / 21 mph 54 / 49°F 83% 1019 mb
Low level cloud: 29%
Mid level cloud: 46%
High level cloud: 31%
Most Significant Cloud Type: low
48%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NW
NW

9 / 17 mph 50 / 46°F 84% 1021 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 18%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sun 09
Jun
00:00

E
E

8 / 15 mph 56 / 54°F 84% 1017 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: medium
43%
0.0 In
06:00

SE
SE

2 / 3 mph 59 / 60°F 75% 1020 mb
Low level cloud: 4%
Mid level cloud: 8%
High level cloud: 18%
Most Significant Cloud Type: low
8%
0.0 In
12:00

W
W

2 / 4 mph 64 / 64°F 74% 1023 mb
Low level cloud: 35%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
62%
0.0 In
18:00

SSW
SSW

12 / 21 mph 58 / 55°F 77% 1015 mb
Low level cloud: 47%
Mid level cloud: 44%
High level cloud: 2%
Most Significant Cloud Type: low
62%
0.0 In
Mon 10
Jun
00:00

N
N

3 / 6 mph 50 / 49°F 89% 1019 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 7%
Most Significant Cloud Type: medium
3%
0.0 In
06:00

NNW
NNW

9 / 18 mph 49 / 46°F 83% 1011 mb
Low level cloud: 32%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
37%
0.0 In
12:00

WNW
WNW

12 / 25 mph 57 / 54°F 83% 1020 mb
Low level cloud: 60%
Mid level cloud: 27%
High level cloud: 8%
Most Significant Cloud Type: low
70%
0.0 In
18:00

NW
NW

8 / 16 mph 56 / 54°F 69% 1020 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 5%
Most Significant Cloud Type: high
4%
0.0 In
Tue 11
Jun
00:00

WNW
WNW

4 / 9 mph 53 / 52°F 92% 1021 mb
Low level cloud: 42%
Mid level cloud: 32%
High level cloud: 22%
Most Significant Cloud Type: low
56%
0.0 In
06:00

W
W

2 / 5 mph 53 / 53°F 85% 1022 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 21%
Most Significant Cloud Type: medium
13%
0.0 In
12:00

WNW
WNW

7 / 15 mph 56 / 54°F 74% 1022 mb
Low level cloud: 44%
Mid level cloud: 30%
High level cloud: 27%
Most Significant Cloud Type: low
57%
0.0 In
18:00

SW
SW

7 / 15 mph 56 / 54°F 67% 1022 mb
Low level cloud: 0%
Mid level cloud: 20%
High level cloud: 33%
Most Significant Cloud Type: medium
20%
0.0 In
Wed 12
Jun
00:00

S
S

7 / 15 mph 51 / 49°F 87% 1021 mb
Low level cloud: 18%
Mid level cloud: 10%
High level cloud: 100%
Most Significant Cloud Type: low
33%
0.0 In
06:00

WSW
WSW

9 / 18 mph 52 / 49°F 93% 1018 mb
Low level cloud: 44%
Mid level cloud: 32%
High level cloud: 99%
Most Significant Cloud Type: low
67%
0.0 In
12:00

SSW
SSW

13 / 28 mph 57 / 54°F 79% 1019 mb
Low level cloud: 0%
Mid level cloud: 74%
High level cloud: 10%
Most Significant Cloud Type: medium
73%
0.0 In
18:00

SSW
SSW

12 / 25 mph 56 / 53°F 85% 1015 mb
Low level cloud: 71%
Mid level cloud: 46%
High level cloud: 16%
Most Significant Cloud Type: low
88%
0.0 In
Thu 13
Jun
00:00

S
S

13 / 28 mph 50 / 46°F 95% 1013 mb
Low level cloud: 94%
Mid level cloud: 98%
High level cloud: 99%
Most Significant Cloud Type: low
100%
0.1 In
06:00

W
W

10 / 21 mph 50 / 47°F 89% 1013 mb
Low level cloud: 50%
Mid level cloud: 43%
High level cloud: 40%
Most Significant Cloud Type: low
69%
0.0 In
12:00

NW
NW

10 / 21 mph 55 / 52°F 94% 1009 mb
Low level cloud: 97%
Mid level cloud: 38%
High level cloud: 13%
Most Significant Cloud Type: low
100%
0.1 In
18:00

SW
SW

9 / 20 mph 56 / 53°F 82% 1013 mb
Low level cloud: 19%
Mid level cloud: 27%
High level cloud: 11%
Most Significant Cloud Type: low
29%
0.0 In
Fri 14
Jun
00:00

SSW
SSW

3 / 6 mph 50 / 50°F 86% 1011 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 62%
Most Significant Cloud Type: medium
15%
0.0 In
06:00

SW
SW

5 / 11 mph 52 / 50°F 91% 1012 mb
Low level cloud: 98%
Mid level cloud: 62%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
12:00

S
S

9 / 19 mph 61 / 61°F 62% 1009 mb
Low level cloud: 15%
Mid level cloud: 67%
High level cloud: 38%
Most Significant Cloud Type: medium
100%
0.0 In
18:00

SSW
SSW

11 / 23 mph 57 / 54°F 94% 1008 mb
Low level cloud: 92%
Mid level cloud: 93%
High level cloud: 18%
Most Significant Cloud Type: low
100%
0.1 In
Sat 15
Jun
00:00

S
S

17 / 36 mph 58 / 54°F 96% 1005 mb
Low level cloud: 94%
Mid level cloud: 74%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
06:00

NW
NW

11 / 23 mph 51 / 47°F 97% 1005 mb
Low level cloud: 99%
Mid level cloud: 100%
High level cloud: 99%
Most Significant Cloud Type: low
100%
0.1 In
12:00

SSW
SSW

19 / 39 mph 60 / 60°F 95% 1004 mb
Low level cloud: 82%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: low
97%
0.1 In
18:00

NNW
NNW

6 / 13 mph 54 / 52°F 90% 1013 mb
Low level cloud: 91%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.1 In
Sun 16
Jun
00:00

SSW
SSW

17 / 37 mph 55 / 51°F 89% 1009 mb
Low level cloud: 49%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
51%
0.0 In
06:00

N
N

3 / 6 mph 51 / 50°F 82% 1015 mb
Low level cloud: 33%
Mid level cloud: 0%
High level cloud: 32%
Most Significant Cloud Type: low
37%
0.0 In
12:00

SSW
SSW

18 / 39 mph 59 / 55°F 74% 1014 mb
Low level cloud: 16%
Mid level cloud: 6%
High level cloud: 79%
Most Significant Cloud Type: low
27%
0.0 In
18:00

W
W

2 / 4 mph 59 / 59°F 69% 1015 mb
Low level cloud: 1%
Mid level cloud: 13%
High level cloud: 48%
Most Significant Cloud Type: medium
16%
0.0 In
Mon 17
Jun
00:00

S
S

7 / 14 mph 55 / 53°F 94% 1014 mb
Low level cloud: 15%
Mid level cloud: 46%
High level cloud: 49%
Most Significant Cloud Type: medium
90%
0.0 In
06:00

SSE
SSE

5 / 11 mph 52 / 51°F 81% 1013 mb
Low level cloud: 24%
Mid level cloud: 90%
High level cloud: 0%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

N
N

4 / 8 mph 59 / 59°F 96% 1011 mb
Low level cloud: 92%
Mid level cloud: 97%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
18:00

SSE
SSE

8 / 17 mph 57 / 55°F 92% 1010 mb
Low level cloud: 90%
Mid level cloud: 88%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 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