Fast Forecast

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Balcombe 14 Day Long Range Forecast

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

West Sussex, United Kingdom

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

Over the next 14 days the Balcombe forecast suggests the average daytime maximum temperature will be around 13°C, with a high for the two weeks of 16°C expected on the afternoon of Tuesday 21st. The average minimum temperature will be 8°C, dipping to its lowest on the morning of Monday 27th at 4°C. The fortnight ahead will have some days seeing a little precipitation and some days with rain. Predictions are Monday 20th will have the most precipitation with an accumulation of around 18.0mm. On the whole winds are likely to be moderate. Expect the strongest wind on the morning of Thursday 23rd, coming from a southerly direction, and reaching around 31mph.

DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Mon 20
Oct		21:00

W
W

 12 / 16 mph 55 / 52°F 95% 988 mb
Low level cloud: 74%
Mid level cloud: 27%
High level cloud: 4%
Most Significant Cloud Type: low
84%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 21
Oct		00:00

WSW
WSW

 13 / 19 mph 52 / 48°F 93% 990 mb
Low level cloud: 45%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: low
52%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WSW
WSW

 12 / 19 mph 52 / 48°F 94% 991 mb
Low level cloud: 86%
Mid level cloud: 29%
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

WSW
WSW

 11 / 17 mph 52 / 48°F 94% 993 mb
Low level cloud: 57%
Mid level cloud: 15%
High level cloud: 16%
Most Significant Cloud Type: low
64%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WSW
WSW

 13 / 16 mph 55 / 51°F 86% 994 mb
Low level cloud: 76%
Mid level cloud: 14%
High level cloud: 100%
Most Significant Cloud Type: low
93%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WSW
WSW

 15 / 17 mph 60 / 59°F 71% 994 mb
Low level cloud: 42%
Mid level cloud: 22%
High level cloud: 29%
Most Significant Cloud Type: low
53%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

WSW
WSW

 14 / 18 mph 58 / 55°F 75% 994 mb
Low level cloud: 8%
Mid level cloud: 100%
High level cloud: 0%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WSW
WSW

 11 / 14 mph 56 / 54°F 82% 995 mb
Low level cloud: 6%
Mid level cloud: 15%
High level cloud: 0%
Most Significant Cloud Type: low
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

 7 / 12 mph 51 / 48°F 93% 997 mb
Low level cloud: 19%
Mid level cloud: 10%
High level cloud: 33%
Most Significant Cloud Type: low
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 22
Oct		00:00

WSW
WSW

 5 / 9 mph 49 / 47°F 94% 997 mb
Low level cloud: 13%
Mid level cloud: 9%
High level cloud: 19%
Most Significant Cloud Type: low
18%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WSW
WSW

 3 / 7 mph 47 / 46°F 93% 998 mb
Low level cloud: 10%
Mid level cloud: 49%
High level cloud: 32%
Most Significant Cloud Type: medium
78%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WSW
WSW

 2 / 5 mph 47 / 47°F 92% 998 mb
Low level cloud: 24%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

 3 / 4 mph 52 / 52°F 77% 999 mb
Low level cloud: 77%
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

SSW
SSW

 7 / 8 mph 57 / 55°F 66% 999 mb
Low level cloud: 12%
Mid level cloud: 28%
High level cloud: 0%
Most Significant Cloud Type: low
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

 10 / 12 mph 58 / 55°F 67% 997 mb
Low level cloud: 23%
Mid level cloud: 7%
High level cloud: 9%
Most Significant Cloud Type: low
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSE
SSE

 8 / 14 mph 52 / 49°F 87% 995 mb
Low level cloud: 35%
Mid level cloud: 100%
High level cloud: 62%
Most Significant Cloud Type: low
77%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SE
SE

 21 / 31 mph 54 / 49°F 94% 986 mb
Low level cloud: 100%
Mid level cloud: 99%
High level cloud: 29%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
Thu 23
Oct		00:00

S
S

 32 / 46 mph 58 / 52°F 83% 975 mb
Low level cloud: 89%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
91%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
03:00

WSW
WSW

 29 / 37 mph 46 / 37°F 84% 979 mb
Low level cloud: 97%
Mid level cloud: 54%
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

W
W

 20 / 29 mph 47 / 39°F 79% 982 mb
Low level cloud: 57%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: low
63%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

W
W

 19 / 23 mph 50 / 43°F 77% 985 mb
Low level cloud: 90%
Mid level cloud: 16%
High level cloud: 5%
Most Significant Cloud Type: low
96%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

WNW
WNW

 23 / 27 mph 53 / 47°F 64% 989 mb
Low level cloud: 14%
Mid level cloud: 26%
High level cloud: 33%
Most Significant Cloud Type: low
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

W
W

 23 / 27 mph 51 / 44°F 59% 993 mb
Low level cloud: 12%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

W
W

 20 / 30 mph 46 / 39°F 62% 996 mb
Low level cloud: 0%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: medium
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

WSW
WSW

 20 / 29 mph 45 / 37°F 77% 997 mb
Low level cloud: 43%
Mid level cloud: 44%
High level cloud: 17%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 24
Oct		00:00

WSW
WSW

 19 / 30 mph 45 / 37°F 71% 996 mb
Low level cloud: 38%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: low
44%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WSW
WSW

 20 / 31 mph 47 / 39°F 64% 995 mb
Low level cloud: 2%
Mid level cloud: 61%
High level cloud: 0%
Most Significant Cloud Type: medium
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WSW
WSW

 24 / 34 mph 49 / 41°F 71% 993 mb
Low level cloud: 94%
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
09:00

WSW
WSW

 21 / 29 mph 51 / 44°F 75% 994 mb
Low level cloud: 24%
Mid level cloud: 40%
High level cloud: 0%
Most Significant Cloud Type: low
37%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

 22 / 26 mph 55 / 49°F 68% 996 mb
Low level cloud: 57%
Mid level cloud: 26%
High level cloud: 0%
Most Significant Cloud Type: low
66%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

W
W

 21 / 28 mph 53 / 47°F 71% 997 mb
Low level cloud: 42%
Mid level cloud: 47%
High level cloud: 7%
Most Significant Cloud Type: low
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

W
W

 18 / 27 mph 50 / 44°F 76% 999 mb
Low level cloud: 15%
Mid level cloud: 33%
High level cloud: 3%
Most Significant Cloud Type: low
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

 18 / 28 mph 49 / 42°F 76% 1000 mb
Low level cloud: 23%
Mid level cloud: 17%
High level cloud: 21%
Most Significant Cloud Type: low
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 25
Oct		00:00

W
W

 20 / 37 mph 47 / 39°F 74% 1000 mb
Low level cloud: 89%
Mid level cloud: 59%
High level cloud: 21%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

 21 / 45 mph 45 / 37°F 74% 1000 mb
Low level cloud: 90%
Mid level cloud: 100%
High level cloud: 69%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

WNW
WNW

 19 / 40 mph 44 / 36°F 77% 1000 mb
Low level cloud: 99%
Mid level cloud: 100%
High level cloud: 97%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WNW
WNW

 18 / 30 mph 47 / 40°F 75% 1002 mb
Low level cloud: 93%
Mid level cloud: 51%
High level cloud: 14%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

W
W

 17 / 23 mph 50 / 44°F 70% 1003 mb
Low level cloud: 82%
Mid level cloud: 64%
High level cloud: 25%
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 / 18 mph 51 / 46°F 68% 1003 mb
Low level cloud: 30%
Mid level cloud: 43%
High level cloud: 5%
Most Significant Cloud Type: low
46%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

 14 / 16 mph 50 / 45°F 74% 1004 mb
Low level cloud: 34%
Mid level cloud: 46%
High level cloud: 14%
Most Significant Cloud Type: low
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

 14 / 16 mph 48 / 42°F 74% 1004 mb
Low level cloud: 87%
Mid level cloud: 46%
High level cloud: 18%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 26
Oct		00:00

WNW
WNW

 14 / 21 mph 45 / 38°F 83% 1004 mb
Low level cloud: 18%
Mid level cloud: 21%
High level cloud: 39%
Most Significant Cloud Type: low
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

WNW
WNW

 15 / 23 mph 43 / 36°F 79% 1004 mb
Low level cloud: 22%
Mid level cloud: 20%
High level cloud: 32%
Most Significant Cloud Type: low
33%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NW
NW

 15 / 28 mph 41 / 34°F 75% 1005 mb
Low level cloud: 91%
Mid level cloud: 43%
High level cloud: 5%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NW
NW

 15 / 20 mph 44 / 37°F 87% 1007 mb
Low level cloud: 99%
Mid level cloud: 71%
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

NW
NW

 17 / 25 mph 48 / 42°F 71% 1008 mb
Low level cloud: 99%
Mid level cloud: 16%
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

NW
NW

 16 / 19 mph 50 / 44°F 77% 1010 mb
Low level cloud: 92%
Mid level cloud: 24%
High level cloud: 46%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNW
NNW

 14 / 16 mph 48 / 43°F 74% 1013 mb
Low level cloud: 93%
Mid level cloud: 29%
High level cloud: 2%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NW
NW

 11 / 15 mph 46 / 41°F 68% 1014 mb
Low level cloud: 26%
Mid level cloud: 4%
High level cloud: 100%
Most Significant Cloud Type: low
39%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Mon 27
Oct		00:00

NNE
NNE

 6 / 12 mph 51 / 49°F 83% 1025 mb
Low level cloud: 9%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
10%
0.0 In
06:00

WSW
WSW

 5 / 11 mph 43 / 40°F 84% 1031 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 17%
Most Significant Cloud Type: medium
23%
0.0 In
12:00

WNW
WNW

 13 / 27 mph 59 / 60°F 73% 1027 mb
Low level cloud: 51%
Mid level cloud: 12%
High level cloud: 19%
Most Significant Cloud Type: low
57%
0.0 In
18:00

W
W

 9 / 20 mph 57 / 55°F 85% 1028 mb
Low level cloud: 50%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: low
50%
0.0 In
Tue 28
Oct		00:00

W
W

 6 / 14 mph 49 / 46°F 95% 1025 mb
Low level cloud: 21%
Mid level cloud: 13%
High level cloud: 22%
Most Significant Cloud Type: low
28%
0.0 In
06:00

W
W

 6 / 13 mph 50 / 47°F 94% 1026 mb
Low level cloud: 17%
Mid level cloud: 30%
High level cloud: 10%
Most Significant Cloud Type: low
28%
0.0 In
12:00

W
W

 10 / 21 mph 55 / 52°F 79% 1025 mb
Low level cloud: 80%
Mid level cloud: 3%
High level cloud: 32%
Most Significant Cloud Type: low
84%
0.0 In
18:00

W
W

 7 / 14 mph 59 / 59°F 77% 1024 mb
Low level cloud: 40%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
41%
0.0 In
Wed 29
Oct		00:00

W
W

 9 / 19 mph 50 / 46°F 67% 1022 mb
Low level cloud: 92%
Mid level cloud: 0%
High level cloud: 21%
Most Significant Cloud Type: low
95%
0.0 In
06:00

SSW
SSW

 3 / 6 mph 50 / 50°F 85% 1020 mb
Low level cloud: 28%
Mid level cloud: 47%
High level cloud: 100%
Most Significant Cloud Type: low
55%
0.0 In
12:00

WSW
WSW

 13 / 28 mph 58 / 55°F 67% 1020 mb
Low level cloud: 31%
Mid level cloud: 40%
High level cloud: 100%
Most Significant Cloud Type: low
56%
0.0 In
18:00

SSE
SSE

 4 / 9 mph 54 / 54°F 87% 1015 mb
Low level cloud: 20%
Mid level cloud: 61%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
Thu 30
Oct		00:00

SW
SW

 15 / 31 mph 55 / 51°F 87% 1015 mb
Low level cloud: 45%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
92%
0.0 In
06:00

W
W

 5 / 11 mph 51 / 50°F 86% 1014 mb
Low level cloud: 9%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
72%
0.0 In
12:00

NNW
NNW

 12 / 26 mph 51 / 47°F 82% 1010 mb
Low level cloud: 49%
Mid level cloud: 89%
High level cloud: 100%
Most Significant Cloud Type: low
92%
0.3 In
18:00

SW
SW

 5 / 11 mph 56 / 55°F 86% 1020 mb
Low level cloud: 2%
Mid level cloud: 46%
High level cloud: 100%
Most Significant Cloud Type: medium
56%
0.0 In
Fri 31
Oct		00:00

WSW
WSW

 11 / 23 mph 47 / 42°F 81% 1011 mb
Low level cloud: 5%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: medium
63%
0.0 In
06:00

SSW
SSW

 15 / 32 mph 55 / 51°F 89% 1019 mb
Low level cloud: 21%
Mid level cloud: 77%
High level cloud: 0%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

WSW
WSW

 11 / 23 mph 50 / 46°F 86% 998 mb
Low level cloud: 31%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
47%
0.1 In
18:00

SW
SW

 22 / 47 mph 59 / 59°F 83% 1016 mb
Low level cloud: 33%
Mid level cloud: 61%
High level cloud: 50%
Most Significant Cloud Type: low
60%
0.0 In
Sat 01
Nov		00:00

W
W

 13 / 28 mph 44 / 37°F 82% 1001 mb
Low level cloud: 6%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: low
12%
0.0 In
06:00

SW
SW

 16 / 33 mph 58 / 55°F 97% 1015 mb
Low level cloud: 100%
Mid level cloud: 89%
High level cloud: 1%
Most Significant Cloud Type: low
100%
0.1 In
12:00

WNW
WNW

 15 / 31 mph 49 / 44°F 66% 997 mb
Low level cloud: 57%
Mid level cloud: 26%
High level cloud: 0%
Most Significant Cloud Type: low
65%
0.0 In
18:00

SW
SW

 21 / 45 mph 60 / 60°F 89% 1013 mb
Low level cloud: 100%
Mid level cloud: 4%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
Sun 02
Nov		00:00

NW
NW

 19 / 39 mph 45 / 37°F 79% 996 mb
Low level cloud: 91%
Mid level cloud: 43%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.0 In
06:00

WSW
WSW

 16 / 34 mph 56 / 51°F 90% 1007 mb
Low level cloud: 68%
Mid level cloud: 49%
High level cloud: 75%
Most Significant Cloud Type: low
94%
0.1 In
12:00

NW
NW

 10 / 20 mph 53 / 50°F 60% 998 mb
Low level cloud: 8%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: low
9%
0.0 In
18:00

WSW
WSW

 15 / 31 mph 49 / 44°F 67% 1015 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
0.0 In
Mon 03
Nov		00:00

NNE
NNE

 11 / 23 mph 46 / 40°F 65% 997 mb
Low level cloud: 4%
Mid level cloud: 99%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
06:00

WSW
WSW

 7 / 14 mph 46 / 43°F 87% 1018 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
12:00

NNW
NNW

 16 / 34 mph 45 / 38°F 56% 1001 mb
Low level cloud: 13%
Mid level cloud: 9%
High level cloud: 4%
Most Significant Cloud Type: low
16%
0.0 In
18:00

SW
SW

 9 / 19 mph 50 / 46°F 81% 1014 mb
Low level cloud: 8%
Mid level cloud: 44%
High level cloud: 21%
Most Significant Cloud Type: medium
67%
0.0 In
Tue 04
Nov		00:00

NNW
NNW

 12 / 26 mph 39 / 31°F 70% 1005 mb
Low level cloud: 12%
Mid level cloud: 9%
High level cloud: 13%
Most Significant Cloud Type: low
16%
0.0 In
06:00

SSW
SSW

 21 / 44 mph 51 / 44°F 86% 1004 mb
Low level cloud: 100%
Mid level cloud: 95%
High level cloud: 16%
Most Significant Cloud Type: low
100%
0.0 In
12:00

NW
NW

 13 / 27 mph 45 / 38°F 46% 1010 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 0%
Most Significant Cloud Type: medium
7%
0.0 In
18:00

NNE
NNE

 6 / 13 mph 57 / 56°F 91% 1004 mb
Low level cloud: 96%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.4 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