WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Windham 14 Day Long Range Forecast

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

Ohio, United States Of America

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

Taking a look at Windham over the coming two weeks and the average daytime maximum temperature will be around 22°C, with a high for the two weeks of 26°C expected on the afternoon of Sunday 2nd. The average minimum temperature will be 11°C, dipping to its lowest on the morning of Thursday 30th at 5°C. The fortnight ahead will have some days seeing a little precipitation and some days with rain. The current forecast indicates Tuesday 4th will have the most precipitation with an accumulation of around 10.0mm. On the whole winds are likely to be moderate.

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

ENE
ENE

3 / 5 mph 63 / 63°F 95% 1012 mb
Low level cloud: 2%
Mid level cloud: 1%
High level cloud: 0%
Most Significant Cloud Type: low
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

E
E

4 / 9 mph 58 / 58°F 96% 1012 mb
Low level cloud: 13%
Mid level cloud: 5%
High level cloud: 2%
Most Significant Cloud Type: low
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

E
E

5 / 8 mph 65 / 63°F 95% 1013 mb
Low level cloud: 29%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
28%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

SE
SE

9 / 10 mph 77 / 77°F 70% 1012 mb
Low level cloud: 37%
Mid level cloud: 24%
High level cloud: 14%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SE
SE

10 / 12 mph 80 / 80°F 61% 1009 mb
Low level cloud: 24%
Mid level cloud: 10%
High level cloud: 67%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SE
SE

11 / 14 mph 79 / 80°F 65% 1006 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 99%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

SSW
SSW

15 / 27 mph 71 / 69°F 83% 1005 mb
Low level cloud: 6%
Mid level cloud: 44%
High level cloud: 81%
Most Significant Cloud Type: medium
64%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
22:00

SSW
SSW

13 / 20 mph 64 / 64°F 97% 1005 mb
Low level cloud: 99%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
Mon 27
May
19:00

W
W

13 / 20 mph 62 / 62°F 76% 1005 mb
Low level cloud: 78%
Mid level cloud: 25%
High level cloud: 0%
Most Significant Cloud Type: low
87%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

12 / 19 mph 59 / 56°F 81% 1007 mb
Low level cloud: 51%
Mid level cloud: 2%
High level cloud: 0%
Most Significant Cloud Type: low
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 28
May
01:00

WSW
WSW

12 / 19 mph 58 / 55°F 82% 1007 mb
Low level cloud: 31%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: low
34%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

10 / 16 mph 55 / 52°F 90% 1007 mb
Low level cloud: 31%
Mid level cloud: 11%
High level cloud: 0%
Most Significant Cloud Type: low
35%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

W
W

11 / 13 mph 59 / 55°F 83% 1009 mb
Low level cloud: 46%
Mid level cloud: 30%
High level cloud: 0%
Most Significant Cloud Type: low
56%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

W
W

15 / 18 mph 64 / 63°F 74% 1009 mb
Low level cloud: 93%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

WNW
WNW

15 / 21 mph 62 / 60°F 84% 1010 mb
Low level cloud: 38%
Mid level cloud: 46%
High level cloud: 1%
Most Significant Cloud Type: low
54%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
16:00

NW
NW

15 / 20 mph 65 / 64°F 68% 1011 mb
Low level cloud: 79%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: low
84%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

NW
NW

7 / 11 mph 62 / 60°F 79% 1013 mb
Low level cloud: 14%
Mid level cloud: 35%
High level cloud: 0%
Most Significant Cloud Type: low
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WNW
WNW

4 / 9 mph 52 / 51°F 96% 1014 mb
Low level cloud: 61%
Mid level cloud: 17%
High level cloud: 5%
Most Significant Cloud Type: low
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 29
May
01:00

WNW
WNW

4 / 8 mph 51 / 50°F 96% 1014 mb
Low level cloud: 5%
Mid level cloud: 37%
High level cloud: 0%
Most Significant Cloud Type: medium
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WSW
WSW

5 / 10 mph 50 / 48°F 94% 1014 mb
Low level cloud: 1%
Mid level cloud: 59%
High level cloud: 0%
Most Significant Cloud Type: medium
62%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

WSW
WSW

6 / 8 mph 55 / 52°F 96% 1015 mb
Low level cloud: 67%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
82%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NW
NW

8 / 12 mph 63 / 61°F 82% 1015 mb
Low level cloud: 4%
Mid level cloud: 45%
High level cloud: 21%
Most Significant Cloud Type: medium
57%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
13:00

NNW
NNW

11 / 19 mph 59 / 59°F 88% 1016 mb
Low level cloud: 89%
Mid level cloud: 81%
High level cloud: 18%
Most Significant Cloud Type: low
100%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
16:00

NNW
NNW

11 / 16 mph 59 / 56°F 83% 1016 mb
Low level cloud: 62%
Mid level cloud: 21%
High level cloud: 8%
Most Significant Cloud Type: low
69%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
19:00

NNW
NNW

9 / 12 mph 56 / 52°F 78% 1018 mb
Low level cloud: 1%
Mid level cloud: 39%
High level cloud: 0%
Most Significant Cloud Type: medium
43%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WNW
WNW

5 / 10 mph 46 / 44°F 71% 1019 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 7%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 30
May
01:00

NW
NW

5 / 11 mph 44 / 41°F 84% 1020 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

NW
NW

5 / 10 mph 42 / 39°F 94% 1020 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
07:00

NNW
NNW

6 / 8 mph 52 / 48°F 70% 1021 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

NNW
NNW

7 / 8 mph 62 / 60°F 47% 1020 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
13:00

N
N

10 / 11 mph 65 / 63°F 41% 1019 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
16:00

N
N

11 / 12 mph 63 / 62°F 46% 1019 mb
Low level cloud: 0%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

N
N

6 / 10 mph 57 / 54°F 69% 1020 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

NNW
NNW

6 / 13 mph 48 / 45°F 77% 1022 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
Fri 31
May
01:00

NNW
NNW

6 / 12 mph 46 / 43°F 88% 1022 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
04:00

N
N

5 / 11 mph 43 / 40°F 94% 1022 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 9%
Most Significant Cloud Type: medium
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

N
N

5 / 7 mph 53 / 50°F 75% 1023 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NNW
NNW

8 / 9 mph 65 / 63°F 51% 1024 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 1%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

N
N

9 / 10 mph 69 / 67°F 42% 1023 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 95%
Most Significant Cloud Type: medium
19%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

N
N

10 / 12 mph 67 / 65°F 48% 1023 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 5%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

N
N

4 / 5 mph 65 / 63°F 74% 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

NNW
NNW

4 / 8 mph 56 / 55°F 84% 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
Sat 01
Jun
01:00

NW
NW

5 / 11 mph 49 / 47°F 89% 1025 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
04:00

NNE
NNE

1 / 3 mph 48 / 48°F 92% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 15%
Most Significant Cloud Type: high
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NE
NE

2 / 2 mph 57 / 55°F 80% 1025 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
10:00

NE
NE

2 / 3 mph 70 / 67°F 52% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 6%
Most Significant Cloud Type: high
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

NNW
NNW

0 / 0 mph 76 / 76°F 42% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 3%
Most Significant Cloud Type: high
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

WSW
WSW

3 / 3 mph 76 / 76°F 45% 1021 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 4%
Most Significant Cloud Type: medium
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

NNW
NNW

2 / 4 mph 68 / 64°F 74% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 46%
Most Significant Cloud Type: high
45%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

E
E

5 / 10 mph 58 / 58°F 87% 1021 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 99%
Most Significant Cloud Type: medium
6%
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

ESE
ESE

2 / 4 mph 56 / 57°F 75% 1020 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: high
2%
0.0 In
07:00

S
S

8 / 16 mph 61 / 61°F 74% 1020 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: medium
6%
0.0 In
13:00

S
S

6 / 13 mph 76 / 78°F 46% 1022 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: medium
12%
0.0 In
19:00

WSW
WSW

6 / 13 mph 76 / 79°F 80% 1017 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 21%
Most Significant Cloud Type: medium
15%
0.0 In
Mon 03
Jun
01:00

SW
SW

7 / 15 mph 59 / 57°F 96% 1015 mb
Low level cloud: 1%
Mid level cloud: 41%
High level cloud: 0%
Most Significant Cloud Type: medium
42%
0.0 In
07:00

SW
SW

11 / 23 mph 63 / 63°F 96% 1011 mb
Low level cloud: 92%
Mid level cloud: 32%
High level cloud: 9%
Most Significant Cloud Type: low
100%
0.0 In
13:00

WSW
WSW

5 / 10 mph 71 / 71°F 82% 1011 mb
Low level cloud: 66%
Mid level cloud: 12%
High level cloud: 51%
Most Significant Cloud Type: low
76%
0.0 In
19:00

SSE
SSE

4 / 8 mph 63 / 63°F 98% 1012 mb
Low level cloud: 44%
Mid level cloud: 50%
High level cloud: 99%
Most Significant Cloud Type: low
100%
0.0 In
Tue 04
Jun
01:00

S
S

6 / 13 mph 66 / 66°F 99% 1011 mb
Low level cloud: 39%
Mid level cloud: 6%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
07:00

WSW
WSW

5 / 10 mph 63 / 63°F 95% 1011 mb
Low level cloud: 48%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
63%
0.1 In
13:00

WSW
WSW

10 / 21 mph 70 / 70°F 89% 1005 mb
Low level cloud: 99%
Mid level cloud: 27%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.3 In
19:00

NW
NW

4 / 8 mph 71 / 71°F 78% 1009 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
0.1 In
Wed 05
Jun
01:00

WNW
WNW

3 / 6 mph 63 / 63°F 96% 1007 mb
Low level cloud: 7%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
11%
0.1 In
07:00

W
W

5 / 11 mph 64 / 64°F 85% 1010 mb
Low level cloud: 6%
Mid level cloud: 10%
High level cloud: 6%
Most Significant Cloud Type: low
10%
0.0 In
13:00

W
W

3 / 7 mph 75 / 78°F 68% 1008 mb
Low level cloud: 26%
Mid level cloud: 19%
High level cloud: 100%
Most Significant Cloud Type: low
44%
0.1 In
19:00

NNE
NNE

2 / 4 mph 68 / 68°F 75% 1009 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 21%
Most Significant Cloud Type: medium
46%
0.0 In
Thu 06
Jun
01:00

SSW
SSW

4 / 8 mph 65 / 65°F 91% 1007 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 32%
Most Significant Cloud Type: medium
16%
0.0 In
07:00

SSE
SSE

4 / 8 mph 58 / 59°F 97% 1007 mb
Low level cloud: 72%
Mid level cloud: 100%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.1 In
13:00

WSW
WSW

11 / 24 mph 71 / 71°F 90% 1004 mb
Low level cloud: 38%
Mid level cloud: 6%
High level cloud: 3%
Most Significant Cloud Type: low
40%
0.1 In
19:00

SSE
SSE

2 / 5 mph 67 / 67°F 87% 1003 mb
Low level cloud: 34%
Mid level cloud: 20%
High level cloud: 100%
Most Significant Cloud Type: low
52%
0.0 In
Fri 07
Jun
01:00

W
W

9 / 19 mph 61 / 61°F 98% 1002 mb
Low level cloud: 82%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: low
84%
0.2 In
07:00

NNE
NNE

6 / 14 mph 58 / 57°F 99% 1002 mb
Low level cloud: 97%
Mid level cloud: 90%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.4 In
13:00

WNW
WNW

16 / 33 mph 72 / 76°F 59% 1002 mb
Low level cloud: 15%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
22%
0.0 In
19:00

NNW
NNW

11 / 22 mph 64 / 64°F 82% 1009 mb
Low level cloud: 22%
Mid level cloud: 15%
High level cloud: 0%
Most Significant Cloud Type: low
27%
0.1 In
Sat 08
Jun
01:00

W
W

15 / 30 mph 54 / 50°F 84% 1001 mb
Low level cloud: 29%
Mid level cloud: 30%
High level cloud: 0%
Most Significant Cloud Type: low
39%
0.1 In
07:00

NW
NW

8 / 16 mph 59 / 58°F 86% 1014 mb
Low level cloud: 4%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: low
3%
0.0 In
13:00

WNW
WNW

12 / 26 mph 60 / 60°F 91% 1005 mb
Low level cloud: 90%
Mid level cloud: 43%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.1 In
19:00

NNW
NNW

6 / 12 mph 65 / 65°F 79% 1016 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Sun 09
Jun
01:00

WNW
WNW

4 / 9 mph 53 / 53°F 96% 1011 mb
Low level cloud: 31%
Mid level cloud: 46%
High level cloud: 13%
Most Significant Cloud Type: low
48%
0.1 In
07:00

SSW
SSW

1 / 2 mph 64 / 64°F 81% 1018 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
13:00

N
N

7 / 15 mph 70 / 70°F 51% 1013 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 0%
Most Significant Cloud Type: medium
44%
0.0 In
19:00

WSW
WSW

5 / 10 mph 71 / 71°F 79% 1013 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 5%
Most Significant Cloud Type: high
5%
0.0 In
Mon 10
Jun
01:00

NW
NW

4 / 9 mph 52 / 51°F 68% 1017 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 4%
Most Significant Cloud Type: medium
5%
0.0 In
07:00

SSW
SSW

8 / 16 mph 63 / 64°F 81% 1012 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 15%
Most Significant Cloud Type: medium
12%
0.0 In
13:00

NNE
NNE

6 / 13 mph 73 / 75°F 39% 1016 mb
Low level cloud: 0%
Mid level cloud: 18%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
0.0 In
19:00

SSW
SSW

6 / 12 mph 76 / 79°F 81% 1007 mb
Low level cloud: 0%
Mid level cloud: 19%
High level cloud: 33%
Most Significant Cloud Type: medium
19%
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