Fast Forecast

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Broadgreen Wood 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Broadgreen Wood

Hertfordshire, United Kingdom

Long range weather outlook for Broadgreen Wood includes 14 day forecast summary:

The forecast for Broadgreen Wood in the coming two weeks is predicting the average daytime maximum temperature will be around 7°C, with a high for the two weeks of 11°C expected on the afternoon of Monday 12th. The mean minimum temperature will be 4°C, dipping to its lowest on the morning of Saturday 10th at -1°C. The coming 14 days will have some days seeing a little precipitation and some days with rain. Predictions are Friday 16th will have the most precipitation with an accumulation of around 7.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Fri 09
Jan		21:00

NNW
NNW

 19 / 26 mph 36 / 26°F 88% 1002 mb
Low level cloud: 100%
Mid level cloud: 100%
High level cloud: 33%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 10
Jan		00:00

NNW
NNW

 18 / 29 mph 33 / 22°F 85% 1006 mb
Low level cloud: 100%
Mid level cloud: 99%
High level cloud: 58%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNW
NNW

 17 / 30 mph 32 / 21°F 88% 1008 mb
Low level cloud: 83%
Mid level cloud: 70%
High level cloud: 33%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNW
NNW

 15 / 24 mph 31 / 20°F 92% 1011 mb
Low level cloud: 97%
Mid level cloud: 46%
High level cloud: 20%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNW
NNW

 14 / 21 mph 34 / 24°F 89% 1015 mb
Low level cloud: 90%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: low
96%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NNW
NNW

 12 / 17 mph 36 / 28°F 82% 1017 mb
Low level cloud: 94%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
97%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NNW
NNW

 9 / 12 mph 38 / 31°F 80% 1019 mb
Low level cloud: 79%
Mid level cloud: 4%
High level cloud: 7%
Most Significant Cloud Type: low
81%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNW
NNW

 5 / 6 mph 37 / 33°F 88% 1021 mb
Low level cloud: 80%
Mid level cloud: 4%
High level cloud: 87%
Most Significant Cloud Type: low
91%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

ESE
ESE

 2 / 4 mph 35 / 33°F 80% 1022 mb
Low level cloud: 43%
Mid level cloud: 22%
High level cloud: 28%
Most Significant Cloud Type: low
54%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 11
Jan		00:00

SSE
SSE

 6 / 11 mph 32 / 26°F 88% 1023 mb
Low level cloud: 0%
Mid level cloud: 48%
High level cloud: 32%
Most Significant Cloud Type: medium
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

SSE
SSE

 8 / 14 mph 32 / 24°F 87% 1022 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 98%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SSE
SSE

 11 / 18 mph 33 / 25°F 81% 1019 mb
Low level cloud: 0%
Mid level cloud: 71%
High level cloud: 90%
Most Significant Cloud Type: medium
74%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SSE
SSE

 15 / 24 mph 36 / 27°F 82% 1018 mb
Low level cloud: 25%
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
12:00

SSE
SSE

 19 / 28 mph 40 / 30°F 77% 1015 mb
Low level cloud: 71%
Mid level cloud: 90%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSE
SSE

 20 / 31 mph 40 / 31°F 87% 1011 mb
Low level cloud: 98%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

S
S

 21 / 33 mph 42 / 33°F 95% 1008 mb
Low level cloud: 100%
Mid level cloud: 87%
High level cloud: 97%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

S
S

 20 / 33 mph 46 / 38°F 97% 1006 mb
Low level cloud: 100%
Mid level cloud: 98%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 12
Jan		00:00

S
S

 21 / 38 mph 47 / 40°F 96% 1004 mb
Low level cloud: 99%
Mid level cloud: 70%
High level cloud: 43%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
03:00

SW
SW

 19 / 39 mph 45 / 38°F 93% 1004 mb
Low level cloud: 97%
Mid level cloud: 8%
High level cloud: 17%
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 / 31 mph 44 / 37°F 83% 1004 mb
Low level cloud: 81%
Mid level cloud: 9%
High level cloud: 100%
Most Significant Cloud Type: low
96%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SW
SW

 15 / 29 mph 47 / 41°F 85% 1005 mb
Low level cloud: 85%
Mid level cloud: 27%
High level cloud: 35%
Most Significant Cloud Type: low
98%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SSW
SSW

 14 / 22 mph 50 / 45°F 88% 1005 mb
Low level cloud: 94%
Mid level cloud: 24%
High level cloud: 22%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

 13 / 17 mph 52 / 48°F 88% 1004 mb
Low level cloud: 67%
Mid level cloud: 30%
High level cloud: 100%
Most Significant Cloud Type: low
88%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSW
SSW

 12 / 15 mph 51 / 46°F 94% 1005 mb
Low level cloud: 47%
Mid level cloud: 32%
High level cloud: 16%
Most Significant Cloud Type: low
60%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SSW
SSW

 12 / 18 mph 48 / 43°F 95% 1007 mb
Low level cloud: 71%
Mid level cloud: 5%
High level cloud: 16%
Most Significant Cloud Type: low
75%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 13
Jan		00:00

SW
SW

 13 / 21 mph 47 / 41°F 87% 1008 mb
Low level cloud: 88%
Mid level cloud: 1%
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

SSW
SSW

 6 / 10 mph 46 / 44°F 91% 1008 mb
Low level cloud: 81%
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
06:00

SSE
SSE

 6 / 11 mph 46 / 43°F 97% 1008 mb
Low level cloud: 70%
Mid level cloud: 100%
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

S
S

 8 / 14 mph 47 / 43°F 98% 1007 mb
Low level cloud: 91%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
12:00

S
S

 12 / 16 mph 48 / 44°F 97% 1006 mb
Low level cloud: 93%
Mid level cloud: 86%
High level cloud: 98%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
15:00

SSW
SSW

 12 / 14 mph 49 / 44°F 91% 1005 mb
Low level cloud: 94%
Mid level cloud: 67%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSW
SSW

 13 / 17 mph 48 / 43°F 94% 1006 mb
Low level cloud: 99%
Mid level cloud: 52%
High level cloud: 96%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SSW
SSW

 12 / 19 mph 47 / 42°F 95% 1006 mb
Low level cloud: 99%
Mid level cloud: 45%
High level cloud: 98%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 14
Jan		00:00

SW
SW

 11 / 23 mph 45 / 40°F 92% 1006 mb
Low level cloud: 83%
Mid level cloud: 17%
High level cloud: 8%
Most Significant Cloud Type: low
89%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

SW
SW

 9 / 20 mph 44 / 39°F 90% 1007 mb
Low level cloud: 81%
Mid level cloud: 24%
High level cloud: 39%
Most Significant Cloud Type: low
94%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

W
W

 6 / 11 mph 44 / 40°F 96% 1007 mb
Low level cloud: 100%
Mid level cloud: 49%
High level cloud: 4%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

 7 / 9 mph 45 / 42°F 96% 1009 mb
Low level cloud: 97%
Mid level cloud: 57%
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

ENE
ENE

 6 / 8 mph 47 / 44°F 93% 1010 mb
Low level cloud: 98%
Mid level cloud: 20%
High level cloud: 3%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ENE
ENE

 6 / 6 mph 49 / 46°F 94% 1009 mb
Low level cloud: 96%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ESE
ESE

 8 / 9 mph 48 / 44°F 97% 1009 mb
Low level cloud: 85%
Mid level cloud: 100%
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

SE
SE

 6 / 9 mph 46 / 43°F 99% 1008 mb
Low level cloud: 88%
Mid level cloud: 52%
High level cloud: 12%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 15
Jan		00:00

SSW
SSW

 6 / 11 mph 42 / 38°F 97% 1007 mb
Low level cloud: 90%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

SSW
SSW

 5 / 11 mph 41 / 37°F 93% 1006 mb
Low level cloud: 90%
Mid level cloud: 100%
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

WNW
WNW

 7 / 15 mph 40 / 35°F 95% 1006 mb
Low level cloud: 68%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
84%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

WNW
WNW

 6 / 8 mph 42 / 38°F 94% 1007 mb
Low level cloud: 8%
Mid level cloud: 45%
High level cloud: 44%
Most Significant Cloud Type: medium
70%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

SW
SW

 7 / 10 mph 45 / 40°F 80% 1008 mb
Low level cloud: 0%
Mid level cloud: 100%
High level cloud: 1%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

 6 / 8 mph 46 / 43°F 82% 1007 mb
Low level cloud: 32%
Mid level cloud: 45%
High level cloud: 8%
Most Significant Cloud Type: low
49%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSE
SSE

 6 / 9 mph 45 / 42°F 88% 1006 mb
Low level cloud: 86%
Mid level cloud: 78%
High level cloud: 68%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SE
SE

 6 / 11 mph 43 / 39°F 96% 1005 mb
Low level cloud: 89%
Mid level cloud: 92%
High level cloud: 95%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Fri 16
Jan		00:00

SSE
SSE

 9 / 18 mph 43 / 38°F 96% 1010 mb
Low level cloud: 70%
Mid level cloud: 29%
High level cloud: 20%
Most Significant Cloud Type: low
82%
0.0 In
06:00

S
S

 15 / 32 mph 40 / 32°F 88% 1006 mb
Low level cloud: 99%
Mid level cloud: 98%
High level cloud: 96%
Most Significant Cloud Type: low
100%
0.0 In
12:00

SSE
SSE

 17 / 26 mph 45 / 38°F 88% 1001 mb
Low level cloud: 98%
Mid level cloud: 44%
High level cloud: 80%
Most Significant Cloud Type: low
100%
0.0 In
18:00

SSE
SSE

 9 / 12 mph 49 / 44°F 92% 1010 mb
Low level cloud: 86%
Mid level cloud: 100%
High level cloud: 40%
Most Significant Cloud Type: low
100%
0.0 In
Sat 17
Jan		00:00

SSE
SSE

 5 / 8 mph 43 / 40°F 98% 1013 mb
Low level cloud: 62%
Mid level cloud: 31%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.0 In
06:00

S
S

 14 / 24 mph 41 / 33°F 86% 999 mb
Low level cloud: 17%
Mid level cloud: 26%
High level cloud: 97%
Most Significant Cloud Type: low
37%
0.0 In
12:00

NNW
NNW

 10 / 18 mph 44 / 38°F 97% 981 mb
Low level cloud: 100%
Mid level cloud: 78%
High level cloud: 15%
Most Significant Cloud Type: low
100%
0.0 In
18:00

SW
SW

 7 / 12 mph 45 / 41°F 80% 999 mb
Low level cloud: 79%
Mid level cloud: 0%
High level cloud: 45%
Most Significant Cloud Type: low
84%
0.0 In
Sun 18
Jan		00:00

SE
SE

 9 / 13 mph 40 / 35°F 96% 993 mb
Low level cloud: 48%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: low
49%
0.0 In
06:00

SSE
SSE

 6 / 12 mph 39 / 35°F 96% 1003 mb
Low level cloud: 47%
Mid level cloud: 4%
High level cloud: 1%
Most Significant Cloud Type: low
48%
0.0 In
12:00

SSE
SSE

 22 / 33 mph 42 / 33°F 92% 983 mb
Low level cloud: 100%
Mid level cloud: 85%
High level cloud: 21%
Most Significant Cloud Type: low
100%
0.0 In
18:00

S
S

 16 / 25 mph 44 / 37°F 87% 1005 mb
Low level cloud: 74%
Mid level cloud: 7%
High level cloud: 45%
Most Significant Cloud Type: low
81%
0.0 In
Mon 19
Jan		00:00

SSE
SSE

 10 / 15 mph 39 / 32°F 93% 986 mb
Low level cloud: 36%
Mid level cloud: 44%
High level cloud: 100%
Most Significant Cloud Type: low
63%
0.1 In
06:00

S
S

 22 / 35 mph 46 / 38°F 96% 999 mb
Low level cloud: 100%
Mid level cloud: 86%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
12:00

WNW
WNW

 11 / 18 mph 40 / 34°F 84% 996 mb
Low level cloud: 76%
Mid level cloud: 2%
High level cloud: 100%
Most Significant Cloud Type: low
88%
0.1 In
18:00

SW
SW

 21 / 35 mph 52 / 46°F 80% 995 mb
Low level cloud: 28%
Mid level cloud: 20%
High level cloud: 11%
Most Significant Cloud Type: low
36%
0.8 In
Tue 20
Jan		00:00

SE
SE

 7 / 12 mph 40 / 35°F 92% 1001 mb
Low level cloud: 19%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
06:00

SW
SW

 17 / 32 mph 45 / 38°F 79% 998 mb
Low level cloud: 19%
Mid level cloud: 15%
High level cloud: 14%
Most Significant Cloud Type: low
25%
0.0 In
12:00

S
S

 15 / 24 mph 51 / 46°F 90% 1000 mb
Low level cloud: 94%
Mid level cloud: 86%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
18:00

SSW
SSW

 17 / 29 mph 48 / 42°F 84% 1002 mb
Low level cloud: 72%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
74%
0.0 In
Wed 21
Jan		00:00

S
S

 12 / 19 mph 50 / 46°F 95% 1004 mb
Low level cloud: 99%
Mid level cloud: 92%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
06:00

SW
SW

 16 / 31 mph 41 / 33°F 84% 1009 mb
Low level cloud: 91%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.0 In
12:00

S
S

 11 / 18 mph 50 / 46°F 97% 1001 mb
Low level cloud: 100%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.1 In
18:00

SSW
SSW

 14 / 25 mph 47 / 40°F 81% 1014 mb
Low level cloud: 7%
Mid level cloud: 28%
High level cloud: 100%
Most Significant Cloud Type: medium
52%
0.0 In
Thu 22
Jan		00:00

WSW
WSW

 10 / 16 mph 46 / 41°F 95% 1006 mb
Low level cloud: 97%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.2 In
06:00

WNW
WNW

 15 / 29 mph 45 / 38°F 88% 1007 mb
Low level cloud: 68%
Mid level cloud: 46%
High level cloud: 47%
Most Significant Cloud Type: low
89%
0.2 In
12:00

SW
SW

 8 / 13 mph 49 / 46°F 79% 1013 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: high
1%
0.0 In
18:00

WNW
WNW

 21 / 40 mph 48 / 41°F 74% 1017 mb
Low level cloud: 93%
Mid level cloud: 29%
High level cloud: 1%
Most Significant Cloud Type: low
100%
0.0 In
Fri 23
Jan		00:00

SSW
SSW

 6 / 11 mph 43 / 39°F 96% 1015 mb
Low level cloud: 42%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
88%
0.0 In
06:00

SSW
SSW

 13 / 24 mph 43 / 37°F 92% 1018 mb
Low level cloud: 72%
Mid level cloud: 80%
High level cloud: 13%
Most Significant Cloud Type: low
100%
0.0 In
12:00

SW
SW

 10 / 16 mph 47 / 43°F 93% 1018 mb
Low level cloud: 71%
Mid level cloud: 15%
High level cloud: 31%
Most Significant Cloud Type: low
80%
0.0 In
18:00

W
W

 8 / 15 mph 45 / 41°F 88% 1018 mb
Low level cloud: 3%
Mid level cloud: 10%
High level cloud: 74%
Most Significant Cloud Type: medium
21%
0.1 In
Sat 24
Jan		00:00

SW
SW

 12 / 21 mph 45 / 39°F 93% 1025 mb
Low level cloud: 28%
Mid level cloud: 9%
High level cloud: 21%
Most Significant Cloud Type: low
33%
0.0 In
06:00

SW
SW

 15 / 28 mph 41 / 33°F 90% 1014 mb
Low level cloud: 20%
Mid level cloud: 98%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
12:00

SW
SW

 13 / 20 mph 50 / 46°F 93% 1028 mb
Low level cloud: 72%
Mid level cloud: 1%
High level cloud: 100%
Most Significant Cloud Type: low
84%
0.0 In
18:00

WNW
WNW

 11 / 21 mph 46 / 41°F 94% 998 mb
Low level cloud: 97%
Mid level cloud: 98%
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