WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Appomattox 14 Day Long Range Forecast

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

Virginia, United States Of America

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

For Appomattox in the coming two weeks the average daytime maximum temperature will be around 26°C, with a high for the two weeks of 33°C expected on the afternoon of Sunday 26th. The mean minimum temperature will be 16°C, dipping to its lowest on the morning of Friday 31st at 8°C. Expect the following 14 days ahead to have some days seeing a little precipitation and some days with rain. Predictions are Monday 27th will have the most precipitation with an accumulation of around 8.0mm. On the whole winds are likely to be light.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Wed 22
May
01:00

SSW
SSW

4 / 8 mph 64 / 64°F 88% 1015 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 2%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

SSW
SSW

4 / 9 mph 62 / 62°F 92% 1016 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: medium
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

SW
SW

6 / 9 mph 69 / 66°F 79% 1017 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

SW
SW

6 / 7 mph 83 / 82°F 55% 1015 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
13:00

SSW
SSW

6 / 7 mph 90 / 88°F 41% 1014 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 16%
Most Significant Cloud Type: medium
30%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

S
S

8 / 13 mph 86 / 86°F 53% 1012 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 33%
Most Significant Cloud Type: medium
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

SSW
SSW

6 / 11 mph 80 / 79°F 73% 1013 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: medium
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

SW
SW

5 / 11 mph 71 / 71°F 83% 1013 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 3%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 23
May
19:00

W
W

4 / 7 mph 71 / 68°F 94% 1012 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 0%
Most Significant Cloud Type: medium
22%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

SW
SW

3 / 6 mph 66 / 66°F 96% 1014 mb
Low level cloud: 0%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: medium
20%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 24
May
01:00

NW
NW

3 / 5 mph 64 / 64°F 97% 1013 mb
Low level cloud: 2%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WNW
WNW

1 / 2 mph 62 / 62°F 96% 1012 mb
Low level cloud: 5%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NW
NW

2 / 4 mph 69 / 66°F 87% 1014 mb
Low level cloud: 2%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: medium
20%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

E
E

2 / 2 mph 82 / 80°F 54% 1013 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

S
S

2 / 2 mph 89 / 86°F 42% 1011 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SSW
SSW

3 / 5 mph 83 / 82°F 59% 1010 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: medium
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WSW
WSW

2 / 5 mph 78 / 78°F 77% 1011 mb
Low level cloud: 0%
Mid level cloud: 27%
High level cloud: 3%
Most Significant Cloud Type: medium
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WSW
WSW

3 / 6 mph 71 / 71°F 84% 1011 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
Sat 25
May
01:00

SSW
SSW

2 / 3 mph 67 / 67°F 95% 1011 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 98%
Most Significant Cloud Type: medium
14%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
04:00

WSW
WSW

3 / 6 mph 65 / 65°F 97% 1011 mb
Low level cloud: 8%
Mid level cloud: 33%
High level cloud: 100%
Most Significant Cloud Type: medium
59%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

SW
SW

2 / 3 mph 71 / 68°F 92% 1011 mb
Low level cloud: 4%
Mid level cloud: 26%
High level cloud: 18%
Most Significant Cloud Type: medium
37%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

WSW
WSW

5 / 6 mph 84 / 83°F 55% 1011 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 2%
Most Significant Cloud Type: medium
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SW
SW

5 / 6 mph 90 / 88°F 40% 1009 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 32%
Most Significant Cloud Type: medium
31%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

W
W

5 / 7 mph 90 / 88°F 39% 1008 mb
Low level cloud: 0%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

SW
SW

3 / 6 mph 78 / 78°F 78% 1009 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 32%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WSW
WSW

5 / 10 mph 68 / 68°F 93% 1011 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 6%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 26
May
01:00

SW
SW

3 / 6 mph 67 / 67°F 96% 1011 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WNW
WNW

2 / 5 mph 66 / 65°F 95% 1010 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 8%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

SE
SE

0 / 0 mph 72 / 69°F 90% 1011 mb
Low level cloud: 1%
Mid level cloud: 6%
High level cloud: 4%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

S
S

3 / 3 mph 85 / 84°F 58% 1011 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 21%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SW
SW

9 / 10 mph 91 / 91°F 44% 1010 mb
Low level cloud: 0%
Mid level cloud: 49%
High level cloud: 100%
Most Significant Cloud Type: medium
53%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

W
W

6 / 10 mph 85 / 85°F 61% 1008 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 2%
Most Significant Cloud Type: medium
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WSW
WSW

1 / 2 mph 82 / 82°F 77% 1008 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 7%
Most Significant Cloud Type: medium
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

E
E

5 / 11 mph 69 / 69°F 98% 1010 mb
Low level cloud: 6%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
10%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
Mon 27
May
01:00

S
S

4 / 6 mph 68 / 68°F 99% 1009 mb
Low level cloud: 47%
Mid level cloud: 26%
High level cloud: 37%
Most Significant Cloud Type: low
60%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
04:00

SW
SW

4 / 6 mph 67 / 67°F 99% 1008 mb
Low level cloud: 46%
Mid level cloud: 14%
High level cloud: 11%
Most Significant Cloud Type: low
52%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

SW
SW

6 / 11 mph 74 / 70°F 96% 1009 mb
Low level cloud: 2%
Mid level cloud: 45%
High level cloud: 11%
Most Significant Cloud Type: medium
50%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

SSW
SSW

11 / 12 mph 83 / 83°F 58% 1006 mb
Low level cloud: 1%
Mid level cloud: 7%
High level cloud: 17%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SW
SW

14 / 16 mph 89 / 90°F 44% 1005 mb
Low level cloud: 0%
Mid level cloud: 43%
High level cloud: 0%
Most Significant Cloud Type: medium
43%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SW
SW

7 / 14 mph 81 / 81°F 75% 1004 mb
Low level cloud: 0%
Mid level cloud: 41%
High level cloud: 1%
Most Significant Cloud Type: medium
40%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
19:00

WSW
WSW

8 / 15 mph 77 / 78°F 75% 1006 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: medium
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

8 / 14 mph 71 / 71°F 73% 1008 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 28
May
01:00

WNW
WNW

6 / 11 mph 66 / 66°F 80% 1009 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 3%
Most Significant Cloud Type: medium
9%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

W
W

4 / 8 mph 63 / 63°F 81% 1010 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
07:00

WNW
WNW

7 / 10 mph 66 / 64°F 67% 1012 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: medium
1%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

WNW
WNW

9 / 11 mph 74 / 76°F 47% 1013 mb
Low level cloud: 11%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

WSW
WSW

8 / 9 mph 81 / 78°F 34% 1011 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 0%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

W
W

8 / 11 mph 83 / 79°F 31% 1010 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

NW
NW

2 / 5 mph 76 / 76°F 61% 1010 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WSW
WSW

2 / 5 mph 66 / 67°F 62% 1011 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Wed 29
May
01:00

W
W

3 / 6 mph 65 / 65°F 97% 1009 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 100%
Most Significant Cloud Type: medium
23%
0.0 In
07:00

WSW
WSW

3 / 7 mph 65 / 65°F 95% 1005 mb
Low level cloud: 14%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: low
20%
0.0 In
13:00

WNW
WNW

16 / 34 mph 68 / 69°F 43% 1006 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
46%
0.0 In
19:00

WNW
WNW

9 / 18 mph 65 / 65°F 53% 1009 mb
Low level cloud: 0%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: medium
16%
0.0 In
Thu 30
May
01:00

NW
NW

4 / 8 mph 59 / 59°F 68% 1016 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
07:00

W
W

5 / 11 mph 57 / 56°F 65% 1017 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 6%
Most Significant Cloud Type: medium
7%
0.0 In
13:00

WNW
WNW

6 / 12 mph 75 / 75°F 29% 1018 mb
Low level cloud: 0%
Mid level cloud: 8%
High level cloud: 0%
Most Significant Cloud Type: medium
7%
0.0 In
19:00

W
W

6 / 13 mph 64 / 64°F 59% 1015 mb
Low level cloud: 0%
Mid level cloud: 31%
High level cloud: 0%
Most Significant Cloud Type: medium
31%
0.0 In
Fri 31
May
01:00

N
N

3 / 7 mph 56 / 56°F 61% 1021 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: medium
1%
0.0 In
07:00

WNW
WNW

7 / 14 mph 56 / 54°F 63% 1017 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: medium
8%
0.0 In
13:00

SW
SW

6 / 12 mph 77 / 77°F 31% 1021 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
2%
0.0 In
19:00

WNW
WNW

2 / 4 mph 64 / 64°F 59% 1016 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
45%
0.0 In
Sat 01
Jun
01:00

SW
SW

5 / 11 mph 60 / 60°F 81% 1021 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
0.0 In
07:00

NW
NW

5 / 11 mph 57 / 56°F 58% 1019 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: medium
9%
0.0 In
13:00

SW
SW

7 / 15 mph 86 / 84°F 31% 1019 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: medium
9%
0.0 In
19:00

NE
NE

5 / 11 mph 66 / 66°F 67% 1019 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 12%
Most Significant Cloud Type: medium
10%
0.0 In
Sun 02
Jun
01:00

SSW
SSW

6 / 13 mph 65 / 65°F 76% 1020 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
5%
0.0 In
07:00

NW
NW

4 / 8 mph 61 / 61°F 65% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
13:00

SW
SW

7 / 15 mph 88 / 88°F 34% 1019 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 1%
Most Significant Cloud Type: medium
17%
0.0 In
19:00

E
E

6 / 13 mph 68 / 68°F 66% 1019 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
11%
0.0 In
Mon 03
Jun
01:00

SSW
SSW

5 / 11 mph 69 / 69°F 82% 1018 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 33%
Most Significant Cloud Type: medium
14%
0.0 In
07:00

W
W

3 / 6 mph 63 / 63°F 69% 1020 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: medium
25%
0.0 In
13:00

SW
SW

6 / 13 mph 84 / 86°F 52% 1016 mb
Low level cloud: 5%
Mid level cloud: 55%
High level cloud: 32%
Most Significant Cloud Type: medium
69%
0.0 In
19:00

E
E

4 / 9 mph 72 / 76°F 66% 1014 mb
Low level cloud: 0%
Mid level cloud: 90%
High level cloud: 0%
Most Significant Cloud Type: medium
89%
0.0 In
Tue 04
Jun
01:00

S
S

8 / 16 mph 68 / 68°F 94% 1011 mb
Low level cloud: 21%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: low
48%
0.2 In
07:00

NNE
NNE

1 / 2 mph 67 / 67°F 69% 1014 mb
Low level cloud: 0%
Mid level cloud: 21%
High level cloud: 0%
Most Significant Cloud Type: medium
21%
0.0 In
13:00

SSW
SSW

3 / 6 mph 73 / 77°F 79% 1007 mb
Low level cloud: 26%
Mid level cloud: 29%
High level cloud: 100%
Most Significant Cloud Type: low
47%
0.7 In
19:00

W
W

2 / 5 mph 72 / 76°F 84% 1009 mb
Low level cloud: 0%
Mid level cloud: 37%
High level cloud: 61%
Most Significant Cloud Type: medium
39%
0.0 In
Wed 05
Jun
01:00

SE
SE

2 / 5 mph 67 / 67°F 99% 1006 mb
Low level cloud: 28%
Mid level cloud: 45%
High level cloud: 32%
Most Significant Cloud Type: low
47%
0.5 In
07:00

SSE
SSE

4 / 8 mph 64 / 64°F 97% 1010 mb
Low level cloud: 32%
Mid level cloud: 46%
High level cloud: 57%
Most Significant Cloud Type: low
54%
0.1 In
13:00

SSE
SSE

7 / 15 mph 78 / 80°F 60% 1006 mb
Low level cloud: 2%
Mid level cloud: 25%
High level cloud: 13%
Most Significant Cloud Type: medium
32%
0.2 In
19:00

S
S

9 / 20 mph 64 / 64°F 97% 1011 mb
Low level cloud: 99%
Mid level cloud: 76%
High level cloud: 33%
Most Significant Cloud Type: low
100%
0.2 In
Thu 06
Jun
01:00

ESE
ESE

2 / 4 mph 66 / 66°F 99% 1008 mb
Low level cloud: 46%
Mid level cloud: 43%
High level cloud: 34%
Most Significant Cloud Type: low
65%
0.4 In
07:00

S
S

6 / 12 mph 63 / 63°F 98% 1011 mb
Low level cloud: 70%
Mid level cloud: 18%
High level cloud: 3%
Most Significant Cloud Type: low
76%
0.2 In
13:00

S
S

6 / 12 mph 69 / 69°F 85% 1010 mb
Low level cloud: 48%
Mid level cloud: 7%
High level cloud: 63%
Most Significant Cloud Type: low
58%
0.4 In
19:00

SSW
SSW

4 / 8 mph 73 / 77°F 76% 1007 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 4%
Most Significant Cloud Type: medium
3%
0.1 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