Fast Forecast

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Hampstead Garden Suburb 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Hampstead Garden Suburb

Barnet, United Kingdom

Long range weather outlook for Hampstead Garden Suburb includes 14 day forecast summary:

The next 14 day outlook for Hampstead Garden Suburb shows the average daytime maximum temperature will be around 19°C, with a high for the two weeks of 23°C expected on the afternoon of Friday 24th. The mean minimum temperature will be 11°C, dipping to its lowest on the morning of Tuesday 21st at 8°C. Expect the next 14 days have most days seeing a little rain. Current predictions suggest Wednesday 22nd will have the most precipitation with an accumulation of around 5.0mm. On the whole winds are likely to be light.

DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Wed 15
May		21:00

ESE
ESE

 4 / 5 mph 62 / 62°F 77% 1007 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 2%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 16
May		00:00

E
E

 4 / 5 mph 57 / 57°F 84% 1007 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 37%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

E
E

 3 / 5 mph 55 / 55°F 85% 1006 mb
Low level cloud: 1%
Mid level cloud: 18%
High level cloud: 100%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NE
NE

 4 / 6 mph 57 / 55°F 83% 1006 mb
Low level cloud: 24%
Mid level cloud: 59%
High level cloud: 100%
Most Significant Cloud Type: low
56%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

 6 / 7 mph 59 / 58°F 75% 1006 mb
Low level cloud: 30%
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

N
N

 4 / 5 mph 63 / 61°F 66% 1006 mb
Low level cloud: 40%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
87%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NW
NW

 6 / 8 mph 62 / 62°F 63% 1005 mb
Low level cloud: 32%
Mid level cloud: 100%
High level cloud: 96%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

WNW
WNW

 6 / 7 mph 60 / 60°F 71% 1005 mb
Low level cloud: 15%
Mid level cloud: 69%
High level cloud: 98%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

W
W

 3 / 4 mph 57 / 58°F 84% 1006 mb
Low level cloud: 3%
Mid level cloud: 46%
High level cloud: 95%
Most Significant Cloud Type: medium
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 17
May		00:00

SW
SW

 3 / 4 mph 55 / 56°F 85% 1006 mb
Low level cloud: 14%
Mid level cloud: 21%
High level cloud: 11%
Most Significant Cloud Type: low
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

SSW
SSW

 4 / 6 mph 54 / 53°F 93% 1007 mb
Low level cloud: 20%
Mid level cloud: 7%
High level cloud: 8%
Most Significant Cloud Type: low
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

SSW
SSW

 3 / 4 mph 56 / 54°F 75% 1008 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 11%
Most Significant Cloud Type: high
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

SSW
SSW

 5 / 6 mph 65 / 63°F 58% 1009 mb
Low level cloud: 5%
Mid level cloud: 5%
High level cloud: 7%
Most Significant Cloud Type: low
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

S
S

 7 / 9 mph 67 / 66°F 61% 1010 mb
Low level cloud: 64%
Mid level cloud: 21%
High level cloud: 100%
Most Significant Cloud Type: low
83%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

SSW
SSW

 6 / 7 mph 70 / 68°F 51% 1010 mb
Low level cloud: 68%
Mid level cloud: 8%
High level cloud: 100%
Most Significant Cloud Type: low
82%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

SSW
SSW

 5 / 6 mph 69 / 67°F 63% 1011 mb
Low level cloud: 8%
Mid level cloud: 6%
High level cloud: 100%
Most Significant Cloud Type: medium
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

SW
SW

 3 / 4 mph 60 / 60°F 82% 1013 mb
Low level cloud: 47%
Mid level cloud: 18%
High level cloud: 100%
Most Significant Cloud Type: low
65%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 18
May		00:00

WSW
WSW

 3 / 4 mph 58 / 59°F 90% 1013 mb
Low level cloud: 26%
Mid level cloud: 13%
High level cloud: 100%
Most Significant Cloud Type: low
42%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

W
W

 2 / 4 mph 56 / 57°F 93% 1013 mb
Low level cloud: 19%
Mid level cloud: 56%
High level cloud: 35%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNW
NNW

 2 / 3 mph 58 / 58°F 88% 1013 mb
Low level cloud: 24%
Mid level cloud: 46%
High level cloud: 55%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

 6 / 7 mph 65 / 63°F 69% 1014 mb
Low level cloud: 54%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: low
81%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

 6 / 7 mph 72 / 68°F 53% 1013 mb
Low level cloud: 56%
Mid level cloud: 24%
High level cloud: 65%
Most Significant Cloud Type: low
72%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

 6 / 9 mph 70 / 67°F 72% 1013 mb
Low level cloud: 40%
Mid level cloud: 31%
High level cloud: 0%
Most Significant Cloud Type: low
51%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
18:00

NE
NE

 6 / 9 mph 67 / 65°F 82% 1013 mb
Low level cloud: 17%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
19%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
21:00

NNE
NNE

 6 / 7 mph 58 / 58°F 94% 1015 mb
Low level cloud: 21%
Mid level cloud: 8%
High level cloud: 9%
Most Significant Cloud Type: low
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 19
May		00:00

NNE
NNE

 5 / 7 mph 54 / 53°F 95% 1015 mb
Low level cloud: 39%
Mid level cloud: 31%
High level cloud: 7%
Most Significant Cloud Type: low
50%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

N
N

 5 / 7 mph 52 / 51°F 93% 1015 mb
Low level cloud: 52%
Mid level cloud: 44%
High level cloud: 1%
Most Significant Cloud Type: low
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

N
N

 7 / 9 mph 53 / 51°F 91% 1015 mb
Low level cloud: 81%
Mid level cloud: 42%
High level cloud: 0%
Most Significant Cloud Type: low
95%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NNE
NNE

 9 / 10 mph 57 / 55°F 80% 1016 mb
Low level cloud: 94%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
97%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NNE
NNE

 9 / 10 mph 65 / 63°F 67% 1015 mb
Low level cloud: 76%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: low
83%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

NE
NE

 9 / 13 mph 65 / 63°F 72% 1015 mb
Low level cloud: 19%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
34%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
18:00

NNE
NNE

 11 / 13 mph 63 / 62°F 76% 1016 mb
Low level cloud: 31%
Mid level cloud: 23%
High level cloud: 2%
Most Significant Cloud Type: low
38%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNE
NNE

 10 / 11 mph 54 / 51°F 88% 1018 mb
Low level cloud: 41%
Mid level cloud: 15%
High level cloud: 0%
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

NNE
NNE

 10 / 11 mph 52 / 49°F 80% 1018 mb
Low level cloud: 99%
Mid level cloud: 6%
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

NNE
NNE

 10 / 13 mph 51 / 48°F 77% 1018 mb
Low level cloud: 93%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: low
98%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

 10 / 13 mph 53 / 48°F 73% 1018 mb
Low level cloud: 52%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
56%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

 11 / 12 mph 58 / 55°F 56% 1018 mb
Low level cloud: 2%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: low
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

 10 / 12 mph 64 / 63°F 47% 1018 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
15:00

NE
NE

 11 / 12 mph 66 / 64°F 45% 1016 mb
Low level cloud: 35%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
36%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

NNE
NNE

 11 / 12 mph 63 / 62°F 54% 1017 mb
Low level cloud: 7%
Mid level cloud: 5%
High level cloud: 7%
Most Significant Cloud Type: low
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNE
NNE

 8 / 9 mph 55 / 53°F 74% 1017 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 6%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 21
May		00:00

NNE
NNE

 6 / 7 mph 50 / 47°F 83% 1017 mb
Low level cloud: 14%
Mid level cloud: 18%
High level cloud: 98%
Most Significant Cloud Type: low
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
03:00

NNE
NNE

 6 / 7 mph 48 / 45°F 85% 1016 mb
Low level cloud: 19%
Mid level cloud: 44%
High level cloud: 46%
Most Significant Cloud Type: low
39%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
06:00

NNE
NNE

 6 / 8 mph 50 / 47°F 77% 1015 mb
Low level cloud: 12%
Mid level cloud: 24%
High level cloud: 12%
Most Significant Cloud Type: low
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
09:00

NE
NE

 8 / 9 mph 62 / 60°F 59% 1014 mb
Low level cloud: 53%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
69%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
12:00

NE
NE

 9 / 10 mph 62 / 62°F 67% 1013 mb
Low level cloud: 87%
Mid level cloud: 88%
High level cloud: 21%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
15:00

ENE
ENE

 8 / 10 mph 64 / 63°F 74% 1012 mb
Low level cloud: 93%
Mid level cloud: 25%
High level cloud: 10%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
18:00

ENE
ENE

 9 / 12 mph 60 / 60°F 81% 1012 mb
Low level cloud: 85%
Mid level cloud: 97%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
21:00

NNE
NNE

 6 / 7 mph 57 / 56°F 82% 1013 mb
Low level cloud: 86%
Mid level cloud: 63%
High level cloud: 100%
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
Wed 22
May		00:00

SW
SW

 6 / 13 mph 56 / 55°F 97% 1009 mb
Low level cloud: 73%
Mid level cloud: 28%
High level cloud: 32%
Most Significant Cloud Type: low
86%
0.0 In
06:00

NE
NE

 4 / 9 mph 55 / 55°F 83% 1013 mb
Low level cloud: 64%
Mid level cloud: 46%
High level cloud: 29%
Most Significant Cloud Type: low
83%
0.0 In
12:00

NNW
NNW

 4 / 7 mph 59 / 59°F 96% 1010 mb
Low level cloud: 100%
Mid level cloud: 44%
High level cloud: 15%
Most Significant Cloud Type: low
100%
0.0 In
18:00

N
N

 8 / 17 mph 65 / 65°F 80% 1012 mb
Low level cloud: 75%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: low
79%
0.0 In
Thu 23
May		00:00

NNE
NNE

 3 / 7 mph 59 / 60°F 93% 1013 mb
Low level cloud: 80%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
86%
0.0 In
06:00

SSW
SSW

 3 / 7 mph 66 / 66°F 84% 1021 mb
Low level cloud: 8%
Mid level cloud: 5%
High level cloud: 33%
Most Significant Cloud Type: low
13%
0.0 In
12:00

N
N

 15 / 31 mph 55 / 51°F 96% 1017 mb
Low level cloud: 100%
Mid level cloud: 100%
High level cloud: 21%
Most Significant Cloud Type: low
100%
0.0 In
18:00

E
E

 6 / 12 mph 67 / 67°F 82% 1017 mb
Low level cloud: 25%
Mid level cloud: 43%
High level cloud: 3%
Most Significant Cloud Type: low
40%
0.0 In
Fri 24
May		00:00

NE
NE

 8 / 16 mph 58 / 56°F 99% 1019 mb
Low level cloud: 97%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.1 In
06:00

NNE
NNE

 8 / 16 mph 60 / 60°F 82% 1017 mb
Low level cloud: 7%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
7%
0.0 In
12:00

NNE
NNE

 2 / 4 mph 64 / 64°F 87% 1021 mb
Low level cloud: 90%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: low
97%
0.0 In
18:00

NE
NE

 10 / 21 mph 71 / 71°F 59% 1017 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 3%
Most Significant Cloud Type: high
3%
0.0 In
Sat 25
May		00:00

SSW
SSW

 3 / 6 mph 68 / 68°F 85% 1021 mb
Low level cloud: 17%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
22%
0.0 In
06:00

NNE
NNE

 8 / 16 mph 59 / 59°F 78% 1019 mb
Low level cloud: 2%
Mid level cloud: 6%
High level cloud: 35%
Most Significant Cloud Type: medium
13%
0.0 In
12:00

SW
SW

 6 / 12 mph 74 / 77°F 51% 1019 mb
Low level cloud: 72%
Mid level cloud: 6%
High level cloud: 1%
Most Significant Cloud Type: low
74%
0.0 In
18:00

NNE
NNE

 8 / 16 mph 68 / 68°F 58% 1016 mb
Low level cloud: 14%
Mid level cloud: 17%
High level cloud: 100%
Most Significant Cloud Type: low
31%
0.0 In
Sun 26
May		00:00

NNW
NNW

 2 / 5 mph 67 / 67°F 85% 1019 mb
Low level cloud: 6%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: medium
36%
0.0 In
06:00

NNE
NNE

 5 / 11 mph 59 / 59°F 56% 1017 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
0.0 In
12:00

ENE
ENE

 11 / 22 mph 78 / 80°F 56% 1017 mb
Low level cloud: 7%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
10%
0.0 In
18:00

ESE
ESE

 5 / 10 mph 71 / 71°F 54% 1017 mb
Low level cloud: 26%
Mid level cloud: 0%
High level cloud: 100%
Most Significant Cloud Type: low
37%
0.0 In
Mon 27
May		00:00

ENE
ENE

 10 / 21 mph 65 / 65°F 71% 1017 mb
Low level cloud: 2%
Mid level cloud: 3%
High level cloud: 9%
Most Significant Cloud Type: low
3%
0.0 In
06:00

NW
NW

 7 / 15 mph 57 / 56°F 66% 1018 mb
Low level cloud: 7%
Mid level cloud: 31%
High level cloud: 36%
Most Significant Cloud Type: medium
52%
0.0 In
12:00

NE
NE

 15 / 33 mph 65 / 65°F 47% 1016 mb
Low level cloud: 18%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
19%
0.0 In
18:00

NW
NW

 11 / 23 mph 66 / 66°F 57% 1018 mb
Low level cloud: 39%
Mid level cloud: 22%
High level cloud: 27%
Most Significant Cloud Type: low
49%
0.0 In
Tue 28
May		00:00

NNE
NNE

 13 / 27 mph 53 / 49°F 94% 1010 mb
Low level cloud: 92%
Mid level cloud: 50%
High level cloud: 5%
Most Significant Cloud Type: low
100%
0.1 In
06:00

NW
NW

 9 / 19 mph 57 / 55°F 73% 1019 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 3%
Most Significant Cloud Type: high
3%
0.0 In
12:00

NE
NE

 6 / 13 mph 64 / 64°F 65% 1005 mb
Low level cloud: 94%
Mid level cloud: 44%
High level cloud: 77%
Most Significant Cloud Type: low
100%
0.0 In
18:00

NNW
NNW

 11 / 22 mph 64 / 64°F 49% 1020 mb
Low level cloud: 50%
Mid level cloud: 1%
High level cloud: 16%
Most Significant Cloud Type: low
52%
0.0 In
Wed 29
May		00:00

NE
NE

 3 / 6 mph 61 / 61°F 97% 1007 mb
Low level cloud: 38%
Mid level cloud: 65%
High level cloud: 32%
Most Significant Cloud Type: low
64%
0.1 In
06:00

W
W

 7 / 15 mph 58 / 57°F 69% 1020 mb
Low level cloud: 2%
Mid level cloud: 15%
High level cloud: 100%
Most Significant Cloud Type: medium
24%
0.0 In
12:00

SW
SW

 3 / 6 mph 68 / 68°F 69% 1006 mb
Low level cloud: 82%
Mid level cloud: 66%
High level cloud: 32%
Most Significant Cloud Type: low
100%
0.5 In
18:00

W
W

 13 / 27 mph 63 / 63°F 53% 1016 mb
Low level cloud: 5%
Mid level cloud: 44%
High level cloud: 40%
Most Significant Cloud Type: medium
59%
0.0 In
Thu 30
May		00:00

SW
SW

 3 / 7 mph 64 / 64°F 84% 1007 mb
Low level cloud: 1%
Mid level cloud: 32%
High level cloud: 0%
Most Significant Cloud Type: medium
35%
0.0 In
06:00

W
W

 8 / 16 mph 56 / 55°F 81% 1015 mb
Low level cloud: 72%
Mid level cloud: 30%
High level cloud: 51%
Most Significant Cloud Type: low
88%
0.0 In
12:00

WSW
WSW

 8 / 17 mph 63 / 63°F 80% 1007 mb
Low level cloud: 1%
Mid level cloud: 52%
High level cloud: 37%
Most Significant Cloud Type: medium
56%
0.0 In
18:00

NNW
NNW

 3 / 7 mph 64 / 64°F 88% 1013 mb
Low level cloud: 68%
Mid level cloud: 44%
High level cloud: 9%
Most Significant Cloud Type: low
84%
0.1 In

Other Locations Near to Hampstead Garden Suburb

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