WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Bristol Mountain 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Bristol Mountain

New York, United States Of America

Long range weather outlook for Bristol Mountain includes 14 day forecast summary:

Taking a look at Bristol Mountain over the coming two weeks and the average daytime maximum temperature will be around 20°C, with a high for the two weeks of 25°C expected on the afternoon of Sunday 2nd. The mean minimum temperature will be 12°C, dipping to its lowest on the morning of Thursday 30th at 6°C. The coming 14 days will have some days seeing a little precipitation and some days with rain. Current predictions suggest Monday 27th will have the most precipitation with an accumulation of around 15.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sun 26
May
01:00

W
W

4 / 8 mph 60 / 60°F 97% 1012 mb
Low level cloud: 37%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
41%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WNW
WNW

4 / 7 mph 56 / 56°F 98% 1013 mb
Low level cloud: 63%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NW
NW

1 / 2 mph 61 / 60°F 94% 1014 mb
Low level cloud: 91%
Mid level cloud: 0%
High level cloud: 9%
Most Significant Cloud Type: low
92%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NNE
NNE

3 / 3 mph 67 / 65°F 79% 1014 mb
Low level cloud: 76%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
75%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SE
SE

5 / 6 mph 74 / 76°F 63% 1013 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

E
E

7 / 9 mph 75 / 76°F 64% 1011 mb
Low level cloud: 4%
Mid level cloud: 0%
High level cloud: 22%
Most Significant Cloud Type: low
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

ENE
ENE

6 / 10 mph 69 / 67°F 86% 1011 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 32%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

ESE
ESE

6 / 13 mph 63 / 63°F 89% 1010 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 98%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Mon 27
May
19:00

WSW
WSW

11 / 18 mph 63 / 61°F 92% 1001 mb
Low level cloud: 4%
Mid level cloud: 13%
High level cloud: 20%
Most Significant Cloud Type: medium
24%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
22:00

WSW
WSW

15 / 26 mph 59 / 56°F 90% 1003 mb
Low level cloud: 16%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 28
May
01:00

SW
SW

12 / 19 mph 59 / 57°F 88% 1003 mb
Low level cloud: 81%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
83%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

12 / 20 mph 58 / 55°F 82% 1003 mb
Low level cloud: 52%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: low
53%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

WSW
WSW

17 / 25 mph 61 / 59°F 74% 1004 mb
Low level cloud: 45%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
46%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

WSW
WSW

18 / 22 mph 67 / 65°F 68% 1004 mb
Low level cloud: 55%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: low
63%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

WSW
WSW

20 / 27 mph 66 / 65°F 75% 1003 mb
Low level cloud: 29%
Mid level cloud: 16%
High level cloud: 8%
Most Significant Cloud Type: low
35%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
16:00

WSW
WSW

20 / 26 mph 62 / 61°F 77% 1004 mb
Low level cloud: 35%
Mid level cloud: 45%
High level cloud: 3%
Most Significant Cloud Type: low
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

W
W

19 / 28 mph 55 / 50°F 83% 1006 mb
Low level cloud: 89%
Mid level cloud: 45%
High level cloud: 33%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

18 / 28 mph 53 / 48°F 82% 1006 mb
Low level cloud: 95%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 29
May
01:00

W
W

17 / 24 mph 51 / 46°F 85% 1007 mb
Low level cloud: 100%
Mid level cloud: 65%
High level cloud: 50%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

W
W

15 / 22 mph 49 / 44°F 92% 1008 mb
Low level cloud: 99%
Mid level cloud: 98%
High level cloud: 11%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

WNW
WNW

16 / 23 mph 48 / 42°F 93% 1011 mb
Low level cloud: 98%
Mid level cloud: 96%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

WNW
WNW

16 / 23 mph 46 / 40°F 94% 1012 mb
Low level cloud: 100%
Mid level cloud: 83%
High level cloud: 13%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

WNW
WNW

14 / 21 mph 47 / 41°F 90% 1014 mb
Low level cloud: 91%
Mid level cloud: 59%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

WNW
WNW

15 / 20 mph 59 / 55°F 68% 1013 mb
Low level cloud: 18%
Mid level cloud: 45%
High level cloud: 15%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WNW
WNW

13 / 22 mph 54 / 49°F 74% 1015 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 7%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

9 / 15 mph 50 / 46°F 73% 1016 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 100%
Most Significant Cloud Type: medium
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 30
May
01:00

WSW
WSW

9 / 17 mph 46 / 41°F 79% 1017 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 100%
Most Significant Cloud Type: medium
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

9 / 17 mph 45 / 40°F 80% 1018 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 3%
Most Significant Cloud Type: medium
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

W
W

9 / 13 mph 50 / 46°F 73% 1019 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NW
NW

9 / 11 mph 59 / 56°F 60% 1019 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

NW
NW

10 / 11 mph 63 / 61°F 50% 1018 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
46%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

NW
NW

11 / 16 mph 61 / 59°F 54% 1018 mb
Low level cloud: 0%
Mid level cloud: 28%
High level cloud: 0%
Most Significant Cloud Type: medium
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WNW
WNW

6 / 11 mph 56 / 53°F 73% 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
22:00

W
W

6 / 13 mph 48 / 45°F 73% 1020 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: medium
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 31
May
01:00

WSW
WSW

7 / 15 mph 47 / 44°F 80% 1020 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: medium
21%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

7 / 15 mph 46 / 43°F 81% 1020 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

W
W

7 / 10 mph 52 / 49°F 77% 1022 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NW
NW

9 / 10 mph 62 / 61°F 60% 1021 mb
Low level cloud: 0%
Mid level cloud: 97%
High level cloud: 0%
Most Significant Cloud Type: medium
97%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

NNW
NNW

12 / 14 mph 67 / 65°F 48% 1021 mb
Low level cloud: 0%
Mid level cloud: 16%
High level cloud: 32%
Most Significant Cloud Type: medium
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

NW
NW

11 / 15 mph 66 / 65°F 57% 1021 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 32%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WNW
WNW

6 / 12 mph 62 / 60°F 77% 1021 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 3%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

8 / 17 mph 54 / 51°F 80% 1022 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 1%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 01
Jun
01:00

W
W

7 / 15 mph 51 / 48°F 81% 1023 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

6 / 13 mph 49 / 47°F 81% 1023 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 1%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

W
W

6 / 9 mph 55 / 52°F 73% 1024 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
10:00

NW
NW

6 / 7 mph 66 / 64°F 59% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

N
N

7 / 9 mph 71 / 69°F 48% 1023 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 17%
Most Significant Cloud Type: high
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

NNE
NNE

6 / 8 mph 72 / 69°F 50% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 8%
Most Significant Cloud Type: high
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

S
S

1 / 1 mph 70 / 68°F 71% 1023 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

S
S

3 / 7 mph 57 / 58°F 69% 1024 mb
Low level cloud: 0%
Mid level cloud: 1%
High level cloud: 14%
Most Significant Cloud Type: high
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Sun 02
Jun
01:00

SSW
SSW

6 / 13 mph 51 / 49°F 53% 1020 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 100%
Most Significant Cloud Type: medium
6%
0.0 In
07:00

SSW
SSW

8 / 18 mph 61 / 62°F 71% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
13:00

SE
SE

4 / 8 mph 74 / 77°F 50% 1023 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 19%
Most Significant Cloud Type: medium
9%
0.0 In
19:00

WNW
WNW

6 / 12 mph 73 / 77°F 91% 1016 mb
Low level cloud: 0%
Mid level cloud: 26%
High level cloud: 1%
Most Significant Cloud Type: medium
26%
0.0 In
Mon 03
Jun
01:00

SSW
SSW

8 / 16 mph 58 / 57°F 85% 1014 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
0.0 In
07:00

S
S

15 / 25 mph 60 / 60°F 91% 1012 mb
Low level cloud: 65%
Mid level cloud: 46%
High level cloud: 33%
Most Significant Cloud Type: low
85%
0.0 In
13:00

NW
NW

6 / 13 mph 71 / 71°F 75% 1009 mb
Low level cloud: 37%
Mid level cloud: 11%
High level cloud: 1%
Most Significant Cloud Type: low
41%
0.0 In
19:00

S
S

6 / 14 mph 72 / 77°F 89% 1012 mb
Low level cloud: 1%
Mid level cloud: 46%
High level cloud: 100%
Most Significant Cloud Type: medium
52%
0.0 In
Tue 04
Jun
01:00

WSW
WSW

4 / 9 mph 60 / 60°F 95% 1009 mb
Low level cloud: 10%
Mid level cloud: 1%
High level cloud: 17%
Most Significant Cloud Type: low
12%
0.1 In
07:00

W
W

8 / 17 mph 60 / 60°F 97% 1008 mb
Low level cloud: 62%
Mid level cloud: 65%
High level cloud: 0%
Most Significant Cloud Type: low
85%
0.4 In
13:00

N
N

6 / 12 mph 66 / 66°F 80% 1011 mb
Low level cloud: 70%
Mid level cloud: 6%
High level cloud: 25%
Most Significant Cloud Type: low
74%
0.0 In
19:00

WSW
WSW

7 / 14 mph 65 / 65°F 87% 1008 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
0.1 In
Wed 05
Jun
01:00

W
W

4 / 9 mph 58 / 58°F 95% 1013 mb
Low level cloud: 13%
Mid level cloud: 5%
High level cloud: 7%
Most Significant Cloud Type: low
15%
0.0 In
07:00

WSW
WSW

9 / 18 mph 60 / 60°F 81% 1008 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
0.0 In
13:00

NNW
NNW

6 / 13 mph 61 / 61°F 88% 1015 mb
Low level cloud: 90%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: low
95%
0.0 In
19:00

W
W

4 / 9 mph 66 / 66°F 83% 1009 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 80%
Most Significant Cloud Type: medium
12%
0.0 In
Thu 06
Jun
01:00

NNW
NNW

3 / 7 mph 61 / 60°F 97% 1016 mb
Low level cloud: 86%
Mid level cloud: 57%
High level cloud: 85%
Most Significant Cloud Type: low
100%
0.0 In
07:00

SSW
SSW

5 / 10 mph 63 / 63°F 75% 1008 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 73%
Most Significant Cloud Type: medium
15%
0.0 In
13:00

N
N

8 / 16 mph 64 / 64°F 79% 1018 mb
Low level cloud: 74%
Mid level cloud: 23%
High level cloud: 0%
Most Significant Cloud Type: low
81%
0.0 In
19:00

ESE
ESE

5 / 10 mph 67 / 67°F 88% 1003 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 13%
Most Significant Cloud Type: medium
12%
0.0 In
Fri 07
Jun
01:00

SSW
SSW

2 / 5 mph 60 / 60°F 92% 1016 mb
Low level cloud: 2%
Mid level cloud: 5%
High level cloud: 100%
Most Significant Cloud Type: medium
15%
0.0 In
07:00

ESE
ESE

3 / 7 mph 63 / 63°F 85% 1004 mb
Low level cloud: 3%
Mid level cloud: 22%
High level cloud: 32%
Most Significant Cloud Type: medium
32%
0.0 In
13:00

SW
SW

7 / 15 mph 69 / 69°F 72% 1010 mb
Low level cloud: 0%
Mid level cloud: 67%
High level cloud: 76%
Most Significant Cloud Type: medium
70%
0.0 In
19:00

N
N

5 / 10 mph 67 / 67°F 91% 1007 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 32%
Most Significant Cloud Type: medium
23%
0.1 In
Sat 08
Jun
01:00

WSW
WSW

6 / 12 mph 61 / 61°F 96% 1000 mb
Low level cloud: 2%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: medium
12%
0.4 In
07:00

W
W

9 / 19 mph 58 / 56°F 90% 1010 mb
Low level cloud: 26%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: low
32%
0.0 In
13:00

W
W

14 / 30 mph 62 / 62°F 85% 1000 mb
Low level cloud: 81%
Mid level cloud: 60%
High level cloud: 6%
Most Significant Cloud Type: low
100%
0.0 In
19:00

WNW
WNW

11 / 23 mph 64 / 64°F 78% 1013 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: medium
22%
0.0 In
Sun 09
Jun
01:00

W
W

9 / 18 mph 55 / 52°F 95% 1000 mb
Low level cloud: 80%
Mid level cloud: 35%
High level cloud: 4%
Most Significant Cloud Type: low
92%
0.0 In
07:00

W
W

6 / 13 mph 61 / 61°F 81% 1016 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
0.0 In
13:00

N
N

4 / 9 mph 61 / 61°F 80% 1001 mb
Low level cloud: 55%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: low
65%
0.0 In
19:00

NNW
NNW

4 / 8 mph 74 / 77°F 80% 1012 mb
Low level cloud: 10%
Mid level cloud: 26%
High level cloud: 6%
Most Significant Cloud Type: low
20%
0.0 In
Mon 10
Jun
01:00

NE
NE

1 / 3 mph 53 / 53°F 96% 1003 mb
Low level cloud: 29%
Mid level cloud: 39%
High level cloud: 1%
Most Significant Cloud Type: low
42%
0.0 In
07:00

SW
SW

9 / 18 mph 66 / 66°F 80% 1010 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 16%
Most Significant Cloud Type: medium
13%
0.0 In
13:00

NE
NE

7 / 15 mph 67 / 67°F 58% 1004 mb
Low level cloud: 1%
Mid level cloud: 6%
High level cloud: 2%
Most Significant Cloud Type: medium
8%
0.0 In
19:00

SW
SW

3 / 6 mph 77 / 80°F 81% 1007 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 18%
Most Significant Cloud Type: medium
47%
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