WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Abbots Leigh 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Abbots Leigh

North Somerset, United Kingdom

Long range weather outlook for Abbots Leigh includes 14 day forecast summary:

For Abbots Leigh in the coming two weeks the average daytime maximum temperature will be around 17°C, with a high for the two weeks of 20°C expected on the afternoon of Saturday 18th. The mean minimum temperature will be 10°C, dipping to its lowest on the morning of Tuesday 21st at 5°C. The next 14 days will 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 24.0mm. On the whole winds are likely to be moderate.

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

SE
SE

9 / 11 mph 62 / 60°F 78% 1004 mb
Low level cloud: 11%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ESE
ESE

6 / 12 mph 53 / 51°F 92% 1006 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 1%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 16
May
00:00

E
E

6 / 11 mph 50 / 48°F 92% 1006 mb
Low level cloud: 14%
Mid level cloud: 14%
High level cloud: 2%
Most Significant Cloud Type: low
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

6 / 12 mph 49 / 46°F 94% 1006 mb
Low level cloud: 11%
Mid level cloud: 11%
High level cloud: 36%
Most Significant Cloud Type: low
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

ENE
ENE

6 / 9 mph 53 / 49°F 91% 1006 mb
Low level cloud: 24%
Mid level cloud: 44%
High level cloud: 100%
Most Significant Cloud Type: low
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ENE
ENE

7 / 8 mph 59 / 58°F 81% 1006 mb
Low level cloud: 48%
Mid level cloud: 90%
High level cloud: 100%
Most Significant Cloud Type: low
91%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ENE
ENE

8 / 11 mph 59 / 59°F 86% 1006 mb
Low level cloud: 19%
Mid level cloud: 96%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ENE
ENE

7 / 11 mph 59 / 57°F 88% 1006 mb
Low level cloud: 13%
Mid level cloud: 52%
High level cloud: 100%
Most Significant Cloud Type: medium
90%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
18:00

NNE
NNE

6 / 9 mph 58 / 55°F 93% 1006 mb
Low level cloud: 7%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: medium
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

2 / 4 mph 53 / 54°F 95% 1006 mb
Low level cloud: 25%
Mid level cloud: 45%
High level cloud: 61%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 17
May
00:00

SSE
SSE

1 / 2 mph 51 / 51°F 95% 1007 mb
Low level cloud: 23%
Mid level cloud: 31%
High level cloud: 78%
Most Significant Cloud Type: low
43%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

SW
SW

2 / 5 mph 50 / 50°F 94% 1007 mb
Low level cloud: 13%
Mid level cloud: 30%
High level cloud: 98%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WSW
WSW

3 / 5 mph 54 / 52°F 94% 1008 mb
Low level cloud: 22%
Mid level cloud: 16%
High level cloud: 48%
Most Significant Cloud Type: low
33%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

6 / 6 mph 62 / 59°F 78% 1009 mb
Low level cloud: 18%
Mid level cloud: 13%
High level cloud: 12%
Most Significant Cloud Type: low
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WSW
WSW

6 / 7 mph 66 / 63°F 71% 1009 mb
Low level cloud: 19%
Mid level cloud: 5%
High level cloud: 4%
Most Significant Cloud Type: low
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WSW
WSW

6 / 7 mph 66 / 63°F 75% 1010 mb
Low level cloud: 26%
Mid level cloud: 10%
High level cloud: 32%
Most Significant Cloud Type: low
33%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

4 / 5 mph 65 / 62°F 87% 1011 mb
Low level cloud: 2%
Mid level cloud: 7%
High level cloud: 76%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SW
SW

2 / 5 mph 56 / 57°F 92% 1013 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 85%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 18
May
00:00

SW
SW

1 / 2 mph 53 / 53°F 92% 1013 mb
Low level cloud: 1%
Mid level cloud: 8%
High level cloud: 100%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NW
NW

2 / 3 mph 51 / 51°F 93% 1013 mb
Low level cloud: 7%
Mid level cloud: 7%
High level cloud: 41%
Most Significant Cloud Type: low
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

N
N

3 / 4 mph 55 / 53°F 93% 1014 mb
Low level cloud: 29%
Mid level cloud: 25%
High level cloud: 97%
Most Significant Cloud Type: low
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

6 / 8 mph 61 / 60°F 83% 1015 mb
Low level cloud: 81%
Mid level cloud: 21%
High level cloud: 64%
Most Significant Cloud Type: low
96%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NNE
NNE

8 / 10 mph 67 / 65°F 73% 1014 mb
Low level cloud: 61%
Mid level cloud: 5%
High level cloud: 16%
Most Significant Cloud Type: low
64%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNE
NNE

8 / 11 mph 68 / 65°F 75% 1014 mb
Low level cloud: 56%
Mid level cloud: 9%
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

NNE
NNE

7 / 11 mph 65 / 63°F 88% 1014 mb
Low level cloud: 5%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
9%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
21:00

NNE
NNE

6 / 12 mph 58 / 55°F 95% 1015 mb
Low level cloud: 25%
Mid level cloud: 43%
High level cloud: 0%
Most Significant Cloud Type: low
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 19
May
00:00

NNE
NNE

6 / 11 mph 54 / 52°F 97% 1016 mb
Low level cloud: 49%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: low
58%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNE
NNE

6 / 11 mph 50 / 48°F 97% 1016 mb
Low level cloud: 53%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

N
N

7 / 11 mph 53 / 50°F 95% 1016 mb
Low level cloud: 74%
Mid level cloud: 15%
High level cloud: 0%
Most Significant Cloud Type: low
79%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

10 / 13 mph 55 / 52°F 91% 1017 mb
Low level cloud: 85%
Mid level cloud: 14%
High level cloud: 1%
Most Significant Cloud Type: low
89%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

11 / 14 mph 59 / 56°F 82% 1017 mb
Low level cloud: 82%
Mid level cloud: 22%
High level cloud: 10%
Most Significant Cloud Type: low
91%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

12 / 14 mph 63 / 62°F 71% 1017 mb
Low level cloud: 22%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

11 / 15 mph 61 / 60°F 80% 1017 mb
Low level cloud: 36%
Mid level cloud: 15%
High level cloud: 3%
Most Significant Cloud Type: low
41%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

8 / 14 mph 55 / 51°F 93% 1018 mb
Low level cloud: 39%
Mid level cloud: 21%
High level cloud: 4%
Most Significant Cloud Type: low
46%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 20
May
00:00

NE
NE

10 / 15 mph 49 / 45°F 95% 1019 mb
Low level cloud: 50%
Mid level cloud: 4%
High level cloud: 11%
Most Significant Cloud Type: low
52%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NE
NE

9 / 15 mph 45 / 40°F 95% 1019 mb
Low level cloud: 59%
Mid level cloud: 4%
High level cloud: 12%
Most Significant Cloud Type: low
61%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

11 / 15 mph 47 / 42°F 90% 1020 mb
Low level cloud: 86%
Mid level cloud: 14%
High level cloud: 3%
Most Significant Cloud Type: low
91%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

13 / 14 mph 54 / 50°F 74% 1019 mb
Low level cloud: 90%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: low
98%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

11 / 12 mph 61 / 59°F 64% 1019 mb
Low level cloud: 61%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: low
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

10 / 12 mph 62 / 60°F 64% 1017 mb
Low level cloud: 63%
Mid level cloud: 21%
High level cloud: 3%
Most Significant Cloud Type: low
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

8 / 11 mph 60 / 58°F 73% 1017 mb
Low level cloud: 26%
Mid level cloud: 13%
High level cloud: 12%
Most Significant Cloud Type: low
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

E
E

6 / 11 mph 53 / 49°F 88% 1017 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 13%
Most Significant Cloud Type: high
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 21
May
00:00

ENE
ENE

6 / 9 mph 48 / 45°F 91% 1017 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 5%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

5 / 10 mph 43 / 39°F 92% 1017 mb
Low level cloud: 6%
Mid level cloud: 31%
High level cloud: 13%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

6 / 8 mph 45 / 42°F 88% 1016 mb
Low level cloud: 23%
Mid level cloud: 66%
High level cloud: 47%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

9 / 10 mph 53 / 50°F 74% 1015 mb
Low level cloud: 18%
Mid level cloud: 57%
High level cloud: 25%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

7 / 8 mph 62 / 60°F 61% 1014 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 8%
Most Significant Cloud Type: medium
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

5 / 7 mph 65 / 62°F 68% 1013 mb
Low level cloud: 56%
Mid level cloud: 31%
High level cloud: 3%
Most Significant Cloud Type: low
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NE
NE

6 / 8 mph 63 / 60°F 89% 1012 mb
Low level cloud: 34%
Mid level cloud: 46%
High level cloud: 3%
Most Significant Cloud Type: low
50%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

6 / 11 mph 56 / 52°F 96% 1013 mb
Low level cloud: 34%
Mid level cloud: 46%
High level cloud: 6%
Most Significant Cloud Type: low
50%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Wed 22
May
00:00

WSW
WSW

8 / 17 mph 52 / 50°F 97% 1010 mb
Low level cloud: 40%
Mid level cloud: 27%
High level cloud: 20%
Most Significant Cloud Type: low
51%
0.0 In
06:00

ENE
ENE

6 / 13 mph 51 / 49°F 93% 1012 mb
Low level cloud: 91%
Mid level cloud: 65%
High level cloud: 4%
Most Significant Cloud Type: low
100%
0.0 In
12:00

NNW
NNW

6 / 13 mph 57 / 56°F 94% 1011 mb
Low level cloud: 100%
Mid level cloud: 38%
High level cloud: 61%
Most Significant Cloud Type: low
100%
0.0 In
18:00

N
N

6 / 13 mph 63 / 63°F 88% 1013 mb
Low level cloud: 34%
Mid level cloud: 45%
High level cloud: 2%
Most Significant Cloud Type: low
50%
0.0 In
Thu 23
May
00:00

NNE
NNE

5 / 10 mph 54 / 53°F 97% 1014 mb
Low level cloud: 57%
Mid level cloud: 40%
High level cloud: 1%
Most Significant Cloud Type: low
70%
0.0 In
06:00

S
S

5 / 11 mph 58 / 58°F 92% 1020 mb
Low level cloud: 17%
Mid level cloud: 9%
High level cloud: 22%
Most Significant Cloud Type: low
22%
0.0 In
12:00

N
N

14 / 30 mph 52 / 48°F 93% 1022 mb
Low level cloud: 76%
Mid level cloud: 97%
High level cloud: 99%
Most Significant Cloud Type: low
100%
0.0 In
18:00

E
E

7 / 14 mph 63 / 63°F 93% 1017 mb
Low level cloud: 91%
Mid level cloud: 27%
High level cloud: 32%
Most Significant Cloud Type: low
100%
0.0 In
Fri 24
May
00:00

NNE
NNE

17 / 35 mph 51 / 46°F 94% 1020 mb
Low level cloud: 98%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.5 In
06:00

NNE
NNE

9 / 20 mph 49 / 45°F 93% 1019 mb
Low level cloud: 41%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
40%
0.0 In
12:00

E
E

8 / 17 mph 61 / 61°F 84% 1021 mb
Low level cloud: 92%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: low
99%
0.0 In
18:00

NE
NE

9 / 19 mph 65 / 65°F 79% 1018 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Sat 25
May
00:00

SE
SE

3 / 6 mph 58 / 59°F 94% 1021 mb
Low level cloud: 4%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: low
5%
0.0 In
06:00

NE
NE

6 / 12 mph 54 / 52°F 89% 1020 mb
Low level cloud: 6%
Mid level cloud: 0%
High level cloud: 10%
Most Significant Cloud Type: low
7%
0.0 In
12:00

SSW
SSW

9 / 19 mph 64 / 64°F 69% 1019 mb
Low level cloud: 35%
Mid level cloud: 11%
High level cloud: 100%
Most Significant Cloud Type: low
50%
0.0 In
18:00

W
W

8 / 17 mph 64 / 64°F 82% 1017 mb
Low level cloud: 47%
Mid level cloud: 16%
High level cloud: 14%
Most Significant Cloud Type: low
54%
0.0 In
Sun 26
May
00:00

E
E

2 / 4 mph 59 / 59°F 94% 1019 mb
Low level cloud: 5%
Mid level cloud: 4%
High level cloud: 33%
Most Significant Cloud Type: low
10%
0.0 In
06:00

N
N

4 / 9 mph 56 / 56°F 88% 1017 mb
Low level cloud: 58%
Mid level cloud: 30%
High level cloud: 0%
Most Significant Cloud Type: low
68%
0.0 In
12:00

ENE
ENE

11 / 22 mph 68 / 68°F 84% 1017 mb
Low level cloud: 99%
Mid level cloud: 16%
High level cloud: 9%
Most Significant Cloud Type: low
100%
0.0 In
18:00

W
W

4 / 10 mph 63 / 63°F 90% 1017 mb
Low level cloud: 73%
Mid level cloud: 49%
High level cloud: 12%
Most Significant Cloud Type: low
91%
0.0 In
Mon 27
May
00:00

NE
NE

11 / 24 mph 58 / 56°F 97% 1017 mb
Low level cloud: 71%
Mid level cloud: 2%
High level cloud: 32%
Most Significant Cloud Type: low
74%
0.2 In
06:00

NNW
NNW

5 / 10 mph 58 / 58°F 77% 1020 mb
Low level cloud: 16%
Mid level cloud: 0%
High level cloud: 53%
Most Significant Cloud Type: low
22%
0.0 In
12:00

NE
NE

18 / 38 mph 64 / 64°F 61% 1018 mb
Low level cloud: 43%
Mid level cloud: 1%
High level cloud: 0%
Most Significant Cloud Type: low
43%
0.0 In
18:00

NW
NW

11 / 24 mph 61 / 61°F 75% 1019 mb
Low level cloud: 18%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
20%
0.0 In
Tue 28
May
00:00

N
N

14 / 30 mph 52 / 47°F 87% 1013 mb
Low level cloud: 7%
Mid level cloud: 28%
High level cloud: 3%
Most Significant Cloud Type: medium
46%
0.0 In
06:00

NNE
NNE

5 / 10 mph 56 / 56°F 86% 1021 mb
Low level cloud: 14%
Mid level cloud: 4%
High level cloud: 7%
Most Significant Cloud Type: low
15%
0.0 In
12:00

NNE
NNE

11 / 24 mph 56 / 53°F 88% 1006 mb
Low level cloud: 58%
Mid level cloud: 34%
High level cloud: 100%
Most Significant Cloud Type: low
82%
0.1 In
18:00

NW
NW

12 / 25 mph 57 / 54°F 69% 1021 mb
Low level cloud: 1%
Mid level cloud: 13%
High level cloud: 33%
Most Significant Cloud Type: medium
17%
0.0 In
Wed 29
May
00:00

ESE
ESE

3 / 6 mph 56 / 57°F 97% 1007 mb
Low level cloud: 50%
Mid level cloud: 10%
High level cloud: 100%
Most Significant Cloud Type: low
65%
0.1 In
06:00

WSW
WSW

7 / 15 mph 53 / 51°F 91% 1020 mb
Low level cloud: 19%
Mid level cloud: 4%
High level cloud: 63%
Most Significant Cloud Type: low
27%
0.0 In
12:00

NE
NE

1 / 2 mph 59 / 59°F 96% 1006 mb
Low level cloud: 87%
Mid level cloud: 23%
High level cloud: 34%
Most Significant Cloud Type: low
99%
0.2 In
18:00

WSW
WSW

14 / 29 mph 55 / 51°F 75% 1017 mb
Low level cloud: 1%
Mid level cloud: 80%
High level cloud: 100%
Most Significant Cloud Type: medium
87%
0.0 In
Thu 30
May
00:00

S
S

3 / 7 mph 61 / 61°F 95% 1007 mb
Low level cloud: 8%
Mid level cloud: 16%
High level cloud: 5%
Most Significant Cloud Type: low
14%
0.0 In
06:00

WSW
WSW

8 / 17 mph 55 / 53°F 93% 1015 mb
Low level cloud: 91%
Mid level cloud: 24%
High level cloud: 15%
Most Significant Cloud Type: low
100%
0.0 In
12:00

SW
SW

4 / 8 mph 61 / 61°F 87% 1007 mb
Low level cloud: 18%
Mid level cloud: 54%
High level cloud: 96%
Most Significant Cloud Type: medium
100%
0.0 In
18:00

W
W

11 / 23 mph 59 / 57°F 82% 1014 mb
Low level cloud: 27%
Mid level cloud: 8%
High level cloud: 2%
Most Significant Cloud Type: low
29%
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