WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Affetside 14 Day Long Range Forecast

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

Lancashire, United Kingdom

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

Over the next 14 days the Affetside forecast suggests the average daytime maximum temperature will be around 18°C, with a high for the two weeks of 22°C expected on the afternoon of Friday 24th. The mean minimum temperature will be 10°C, dipping to its lowest on the morning of Monday 20th at 6°C. Expect the next 14 days have mixed weather with some days dry and some seeing a little rain. Current predictions suggest Wednesday 15th will have the most precipitation with an accumulation of around 3.0mm. 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

8 / 11 mph 62 / 60°F 89% 1006 mb
Low level cloud: 31%
Mid level cloud: 42%
High level cloud: 21%
Most Significant Cloud Type: low
48%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

E
E

5 / 9 mph 56 / 53°F 96% 1007 mb
Low level cloud: 9%
Mid level cloud: 17%
High level cloud: 32%
Most Significant Cloud Type: low
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 16
May
00:00

ENE
ENE

4 / 8 mph 51 / 50°F 98% 1007 mb
Low level cloud: 35%
Mid level cloud: 8%
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

ENE
ENE

4 / 7 mph 50 / 49°F 97% 1007 mb
Low level cloud: 48%
Mid level cloud: 9%
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

NE
NE

4 / 6 mph 55 / 53°F 94% 1008 mb
Low level cloud: 43%
Mid level cloud: 67%
High level cloud: 100%
Most Significant Cloud Type: low
78%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

5 / 6 mph 62 / 60°F 80% 1007 mb
Low level cloud: 34%
Mid level cloud: 93%
High level cloud: 6%
Most Significant Cloud Type: low
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

6 / 8 mph 60 / 58°F 84% 1007 mb
Low level cloud: 29%
Mid level cloud: 65%
High level cloud: 100%
Most Significant Cloud Type: low
64%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

7 / 10 mph 60 / 60°F 88% 1006 mb
Low level cloud: 87%
Mid level cloud: 23%
High level cloud: 21%
Most Significant Cloud Type: low
97%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

12 / 16 mph 61 / 60°F 85% 1005 mb
Low level cloud: 27%
Mid level cloud: 9%
High level cloud: 9%
Most Significant Cloud Type: low
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

10 / 15 mph 55 / 51°F 92% 1007 mb
Low level cloud: 72%
Mid level cloud: 17%
High level cloud: 33%
Most Significant Cloud Type: low
81%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 17
May
00:00

NE
NE

8 / 11 mph 54 / 51°F 91% 1007 mb
Low level cloud: 78%
Mid level cloud: 44%
High level cloud: 1%
Most Significant Cloud Type: low
93%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNE
NNE

8 / 10 mph 54 / 51°F 92% 1006 mb
Low level cloud: 88%
Mid level cloud: 43%
High level cloud: 12%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

7 / 10 mph 54 / 51°F 93% 1007 mb
Low level cloud: 92%
Mid level cloud: 47%
High level cloud: 19%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

8 / 10 mph 54 / 51°F 95% 1008 mb
Low level cloud: 95%
Mid level cloud: 57%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

E
E

5 / 7 mph 54 / 53°F 95% 1009 mb
Low level cloud: 96%
Mid level cloud: 46%
High level cloud: 37%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ESE
ESE

4 / 4 mph 57 / 58°F 89% 1010 mb
Low level cloud: 91%
Mid level cloud: 39%
High level cloud: 94%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

E
E

2 / 2 mph 59 / 58°F 87% 1011 mb
Low level cloud: 67%
Mid level cloud: 25%
High level cloud: 8%
Most Significant Cloud Type: low
76%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

2 / 3 mph 57 / 56°F 96% 1013 mb
Low level cloud: 65%
Mid level cloud: 24%
High level cloud: 16%
Most Significant Cloud Type: low
74%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 18
May
00:00

NE
NE

3 / 4 mph 54 / 55°F 96% 1014 mb
Low level cloud: 89%
Mid level cloud: 45%
High level cloud: 29%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NE
NE

3 / 4 mph 53 / 54°F 96% 1014 mb
Low level cloud: 89%
Mid level cloud: 46%
High level cloud: 4%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

2 / 3 mph 56 / 55°F 93% 1015 mb
Low level cloud: 69%
Mid level cloud: 43%
High level cloud: 13%
Most Significant Cloud Type: low
85%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

4 / 4 mph 60 / 59°F 81% 1015 mb
Low level cloud: 89%
Mid level cloud: 43%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

6 / 7 mph 63 / 63°F 72% 1015 mb
Low level cloud: 84%
Mid level cloud: 45%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNE
NNE

8 / 9 mph 66 / 63°F 70% 1015 mb
Low level cloud: 61%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
65%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

6 / 7 mph 66 / 63°F 73% 1015 mb
Low level cloud: 49%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

5 / 7 mph 58 / 55°F 84% 1017 mb
Low level cloud: 24%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 19
May
00:00

NNE
NNE

6 / 9 mph 52 / 50°F 86% 1017 mb
Low level cloud: 36%
Mid level cloud: 7%
High level cloud: 8%
Most Significant Cloud Type: low
39%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNE
NNE

5 / 9 mph 52 / 51°F 81% 1017 mb
Low level cloud: 92%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
95%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

5 / 7 mph 55 / 53°F 82% 1018 mb
Low level cloud: 95%
Mid level cloud: 22%
High level cloud: 12%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

9 / 11 mph 57 / 55°F 76% 1018 mb
Low level cloud: 97%
Mid level cloud: 45%
High level cloud: 5%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

11 / 12 mph 60 / 60°F 72% 1019 mb
Low level cloud: 88%
Mid level cloud: 35%
High level cloud: 17%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

11 / 12 mph 60 / 60°F 67% 1019 mb
Low level cloud: 90%
Mid level cloud: 19%
High level cloud: 80%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NE
NE

11 / 12 mph 58 / 56°F 72% 1019 mb
Low level cloud: 74%
Mid level cloud: 25%
High level cloud: 88%
Most Significant Cloud Type: low
92%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

9 / 12 mph 51 / 47°F 84% 1021 mb
Low level cloud: 15%
Mid level cloud: 28%
High level cloud: 100%
Most Significant Cloud Type: low
36%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 20
May
00:00

NE
NE

7 / 9 mph 48 / 45°F 88% 1021 mb
Low level cloud: 23%
Mid level cloud: 30%
High level cloud: 60%
Most Significant Cloud Type: low
40%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NE
NE

5 / 9 mph 44 / 41°F 87% 1021 mb
Low level cloud: 6%
Mid level cloud: 44%
High level cloud: 20%
Most Significant Cloud Type: medium
61%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

ENE
ENE

9 / 10 mph 47 / 42°F 82% 1021 mb
Low level cloud: 9%
Mid level cloud: 46%
High level cloud: 7%
Most Significant Cloud Type: medium
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ENE
ENE

9 / 11 mph 54 / 51°F 59% 1021 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: medium
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

9 / 10 mph 61 / 60°F 48% 1020 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
15:00

NE
NE

9 / 10 mph 63 / 61°F 47% 1019 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NE
NE

10 / 11 mph 61 / 59°F 59% 1019 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NE
NE

8 / 9 mph 51 / 47°F 80% 1019 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 21
May
00:00

ENE
ENE

5 / 8 mph 45 / 42°F 89% 1018 mb
Low level cloud: 23%
Mid level cloud: 3%
High level cloud: 92%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

ENE
ENE

5 / 7 mph 46 / 44°F 84% 1018 mb
Low level cloud: 78%
Mid level cloud: 3%
High level cloud: 26%
Most Significant Cloud Type: low
82%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

E
E

4 / 5 mph 49 / 48°F 75% 1017 mb
Low level cloud: 78%
Mid level cloud: 14%
High level cloud: 79%
Most Significant Cloud Type: low
92%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

ESE
ESE

5 / 6 mph 57 / 55°F 62% 1016 mb
Low level cloud: 47%
Mid level cloud: 21%
High level cloud: 32%
Most Significant Cloud Type: low
58%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

ESE
ESE

6 / 7 mph 66 / 63°F 48% 1015 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 14%
Most Significant Cloud Type: medium
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ESE
ESE

8 / 10 mph 68 / 66°F 50% 1014 mb
Low level cloud: 23%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
39%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

E
E

12 / 15 mph 59 / 56°F 87% 1014 mb
Low level cloud: 43%
Mid level cloud: 45%
High level cloud: 13%
Most Significant Cloud Type: low
60%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ENE
ENE

10 / 13 mph 53 / 49°F 85% 1016 mb
Low level cloud: 55%
Mid level cloud: 31%
High level cloud: 32%
Most Significant Cloud Type: low
69%
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

4 / 9 mph 56 / 56°F 97% 1007 mb
Low level cloud: 100%
Mid level cloud: 78%
High level cloud: 21%
Most Significant Cloud Type: low
100%
0.0 In
06:00

ENE
ENE

7 / 14 mph 48 / 44°F 81% 1014 mb
Low level cloud: 64%
Mid level cloud: 45%
High level cloud: 16%
Most Significant Cloud Type: low
81%
0.0 In
12:00

NE
NE

12 / 25 mph 55 / 51°F 96% 1013 mb
Low level cloud: 88%
Mid level cloud: 80%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NNE
NNE

8 / 17 mph 50 / 47°F 85% 1015 mb
Low level cloud: 96%
Mid level cloud: 46%
High level cloud: 4%
Most Significant Cloud Type: low
100%
0.0 In
Thu 23
May
00:00

NE
NE

8 / 15 mph 54 / 52°F 94% 1015 mb
Low level cloud: 56%
Mid level cloud: 43%
High level cloud: 90%
Most Significant Cloud Type: low
81%
0.0 In
06:00

S
S

7 / 15 mph 57 / 55°F 82% 1018 mb
Low level cloud: 1%
Mid level cloud: 17%
High level cloud: 100%
Most Significant Cloud Type: medium
25%
0.0 In
12:00

NNE
NNE

16 / 30 mph 59 / 59°F 63% 1024 mb
Low level cloud: 56%
Mid level cloud: 20%
High level cloud: 100%
Most Significant Cloud Type: low
75%
0.0 In
18:00

ENE
ENE

13 / 26 mph 67 / 67°F 70% 1020 mb
Low level cloud: 11%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
10%
0.0 In
Fri 24
May
00:00

NE
NE

11 / 21 mph 52 / 48°F 78% 1024 mb
Low level cloud: 0%
Mid level cloud: 50%
High level cloud: 6%
Most Significant Cloud Type: medium
50%
0.0 In
06:00

NE
NE

9 / 18 mph 54 / 52°F 82% 1022 mb
Low level cloud: 6%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
6%
0.0 In
12:00

E
E

16 / 30 mph 69 / 69°F 60% 1022 mb
Low level cloud: 9%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: low
14%
0.0 In
18:00

ENE
ENE

9 / 17 mph 68 / 68°F 62% 1020 mb
Low level cloud: 3%
Mid level cloud: 0%
High level cloud: 45%
Most Significant Cloud Type: medium
8%
0.0 In
Sat 25
May
00:00

E
E

10 / 19 mph 56 / 54°F 80% 1021 mb
Low level cloud: 70%
Mid level cloud: 45%
High level cloud: 8%
Most Significant Cloud Type: low
86%
0.0 In
06:00

ESE
ESE

1 / 2 mph 61 / 61°F 78% 1020 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 8%
Most Significant Cloud Type: medium
6%
0.0 In
12:00

SE
SE

6 / 11 mph 61 / 61°F 81% 1019 mb
Low level cloud: 90%
Mid level cloud: 47%
High level cloud: 2%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NW
NW

8 / 17 mph 70 / 70°F 65% 1016 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 17%
Most Significant Cloud Type: medium
10%
0.0 In
Sun 26
May
00:00

ENE
ENE

1 / 2 mph 59 / 59°F 91% 1020 mb
Low level cloud: 66%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
69%
0.0 In
06:00

W
W

3 / 5 mph 63 / 63°F 80% 1017 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
7%
0.0 In
12:00

ENE
ENE

13 / 25 mph 72 / 76°F 61% 1020 mb
Low level cloud: 27%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
28%
0.0 In
18:00

WNW
WNW

13 / 25 mph 57 / 54°F 65% 1018 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
12%
0.0 In
Mon 27
May
00:00

ENE
ENE

11 / 22 mph 57 / 54°F 86% 1022 mb
Low level cloud: 24%
Mid level cloud: 0%
High level cloud: 11%
Most Significant Cloud Type: low
25%
0.0 In
06:00

WNW
WNW

8 / 16 mph 52 / 49°F 87% 1019 mb
Low level cloud: 65%
Mid level cloud: 13%
High level cloud: 100%
Most Significant Cloud Type: low
81%
0.0 In
12:00

ENE
ENE

12 / 23 mph 68 / 68°F 49% 1021 mb
Low level cloud: 15%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: low
17%
0.0 In
18:00

WNW
WNW

13 / 27 mph 56 / 52°F 78% 1019 mb
Low level cloud: 87%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
Tue 28
May
00:00

NNE
NNE

7 / 15 mph 52 / 50°F 71% 1017 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 32%
Most Significant Cloud Type: high
31%
0.0 In
06:00

WNW
WNW

6 / 11 mph 52 / 50°F 81% 1020 mb
Low level cloud: 31%
Mid level cloud: 9%
High level cloud: 100%
Most Significant Cloud Type: low
46%
0.0 In
12:00

NE
NE

20 / 40 mph 61 / 61°F 79% 1008 mb
Low level cloud: 64%
Mid level cloud: 88%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
18:00

WNW
WNW

11 / 23 mph 56 / 53°F 63% 1020 mb
Low level cloud: 33%
Mid level cloud: 8%
High level cloud: 100%
Most Significant Cloud Type: low
47%
0.0 In
Wed 29
May
00:00

ENE
ENE

10 / 20 mph 57 / 55°F 93% 1011 mb
Low level cloud: 50%
Mid level cloud: 17%
High level cloud: 6%
Most Significant Cloud Type: low
57%
0.0 In
06:00

W
W

14 / 28 mph 48 / 42°F 79% 1017 mb
Low level cloud: 75%
Mid level cloud: 45%
High level cloud: 62%
Most Significant Cloud Type: low
98%
0.0 In
12:00

ENE
ENE

17 / 34 mph 72 / 76°F 63% 1007 mb
Low level cloud: 4%
Mid level cloud: 19%
High level cloud: 5%
Most Significant Cloud Type: medium
29%
0.0 In
18:00

W
W

15 / 31 mph 54 / 50°F 72% 1013 mb
Low level cloud: 92%
Mid level cloud: 78%
High level cloud: 12%
Most Significant Cloud Type: low
100%
0.0 In
Thu 30
May
00:00

ENE
ENE

5 / 10 mph 60 / 60°F 90% 1007 mb
Low level cloud: 45%
Mid level cloud: 17%
High level cloud: 18%
Most Significant Cloud Type: low
52%
0.0 In
06:00

W
W

10 / 20 mph 49 / 45°F 89% 1013 mb
Low level cloud: 69%
Mid level cloud: 46%
High level cloud: 6%
Most Significant Cloud Type: low
85%
0.0 In
12:00

N
N

0 / 0 mph 71 / 71°F 69% 1005 mb
Low level cloud: 82%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
90%
0.0 In
18:00

W
W

6 / 12 mph 55 / 54°F 77% 1013 mb
Low level cloud: 81%
Mid level cloud: 66%
High level cloud: 32%
Most Significant Cloud Type: low
100%
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