Fast Forecast

WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

San Rafael 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for San Rafael

California, United States Of America

Long range weather outlook for San Rafael includes 14 day forecast summary:

The forecast for San Rafael in the coming two weeks is predicting the average daytime maximum temperature will be around 15°C, with a high for the two weeks of 20°C expected on the afternoon of Thursday 5th. The mean minimum temperature will be 10°C, dipping to its lowest on the morning of Saturday 14th at 4°C. The next 14 days will have mixed overhead conditions with some days dry and some seeing a significant amount of rain. It looks like Wednesday 11th will have the most precipitation with an accumulation of around 14.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Wed 04
Feb		01:00

NNE
NNE

 5 / 11 mph 52 / 50°F 80% 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
04:00

NNE
NNE

 6 / 13 mph 52 / 50°F 79% 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
07:00

NE
NE

 7 / 15 mph 50 / 47°F 81% 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
10:00

NE
NE

 9 / 10 mph 59 / 56°F 71% 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

ENE
ENE

 8 / 10 mph 64 / 63°F 64% 1022 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

NE
NE

 6 / 10 mph 66 / 65°F 63% 1020 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
19:00

NNE
NNE

 5 / 10 mph 60 / 60°F 76% 1020 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

NNE
NNE

 5 / 9 mph 60 / 60°F 80% 1020 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
Thu 05
Feb		22:00

NNE
NNE

 4 / 9 mph 59 / 59°F 68% 1016 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 90%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 06
Feb		01:00

NNW
NNW

 2 / 4 mph 56 / 57°F 70% 1017 mb
Low level cloud: 0%
Mid level cloud: 87%
High level cloud: 87%
Most Significant Cloud Type: medium
90%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

E
E

 2 / 4 mph 56 / 57°F 73% 1017 mb
Low level cloud: 0%
Mid level cloud: 48%
High level cloud: 100%
Most Significant Cloud Type: medium
51%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NE
NE

 2 / 5 mph 56 / 57°F 70% 1018 mb
Low level cloud: 0%
Mid level cloud: 53%
High level cloud: 15%
Most Significant Cloud Type: medium
53%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

ENE
ENE

 4 / 9 mph 59 / 59°F 62% 1019 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 100%
Most Significant Cloud Type: medium
29%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

ENE
ENE

 2 / 5 mph 62 / 61°F 56% 1018 mb
Low level cloud: 0%
Mid level cloud: 33%
High level cloud: 100%
Most Significant Cloud Type: medium
37%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

NW
NW

 5 / 10 mph 62 / 61°F 64% 1019 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 98%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

W
W

 2 / 4 mph 60 / 60°F 67% 1020 mb
Low level cloud: 0%
Mid level cloud: 23%
High level cloud: 92%
Most Significant Cloud Type: medium
26%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WNW
WNW

 3 / 6 mph 58 / 59°F 69% 1021 mb
Low level cloud: 0%
Mid level cloud: 16%
High level cloud: 10%
Most Significant Cloud Type: medium
16%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sat 07
Feb		01:00

NW
NW

 4 / 9 mph 56 / 56°F 76% 1021 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 4%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

N
N

 3 / 7 mph 55 / 55°F 77% 1022 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
07:00

NNE
NNE

 4 / 7 mph 54 / 53°F 75% 1023 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 32%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NE
NE

 2 / 4 mph 58 / 59°F 67% 1025 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
13:00

W
W

 2 / 5 mph 62 / 61°F 60% 1024 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
16:00

WNW
WNW

 7 / 15 mph 61 / 61°F 60% 1023 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 14%
Most Significant Cloud Type: medium
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

W
W

 7 / 10 mph 60 / 60°F 77% 1024 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: high
1%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

W
W

 6 / 11 mph 54 / 53°F 80% 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
Sun 08
Feb		01:00

W
W

 3 / 6 mph 54 / 54°F 81% 1024 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
04:00

SE
SE

 1 / 2 mph 52 / 53°F 80% 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
07:00

NNE
NNE

 2 / 4 mph 52 / 53°F 75% 1024 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

E
E

 1 / 2 mph 58 / 57°F 66% 1024 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
13:00

WSW
WSW

 3 / 4 mph 63 / 62°F 65% 1024 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 6%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

W
W

 8 / 12 mph 63 / 62°F 78% 1023 mb
Low level cloud: 20%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

W
W

 7 / 13 mph 56 / 55°F 94% 1024 mb
Low level cloud: 46%
Mid level cloud: 28%
High level cloud: 0%
Most Significant Cloud Type: low
55%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WSW
WSW

 6 / 11 mph 55 / 54°F 96% 1023 mb
Low level cloud: 38%
Mid level cloud: 24%
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 09
Feb		01:00

W
W

 9 / 13 mph 55 / 52°F 91% 1023 mb
Low level cloud: 32%
Mid level cloud: 34%
High level cloud: 32%
Most Significant Cloud Type: low
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WNW
WNW

 9 / 13 mph 52 / 50°F 88% 1024 mb
Low level cloud: 7%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
65%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NW
NW

 9 / 13 mph 51 / 48°F 85% 1024 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

NNW
NNW

 7 / 8 mph 56 / 53°F 67% 1025 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

NNW
NNW

 4 / 5 mph 60 / 59°F 65% 1023 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

WNW
WNW

 11 / 17 mph 61 / 60°F 60% 1021 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 7%
Most Significant Cloud Type: medium
12%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

WNW
WNW

 10 / 21 mph 52 / 49°F 76% 1021 mb
Low level cloud: 0%
Mid level cloud: 26%
High level cloud: 0%
Most Significant Cloud Type: medium
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

NW
NW

 9 / 15 mph 50 / 46°F 75% 1021 mb
Low level cloud: 0%
Mid level cloud: 30%
High level cloud: 12%
Most Significant Cloud Type: medium
30%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Tue 10
Feb		01:00

NW
NW

 7 / 12 mph 49 / 46°F 72% 1019 mb
Low level cloud: 0%
Mid level cloud: 96%
High level cloud: 73%
Most Significant Cloud Type: medium
98%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

WNW
WNW

 4 / 7 mph 50 / 48°F 68% 1019 mb
Low level cloud: 0%
Mid level cloud: 99%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NW
NW

 4 / 6 mph 50 / 48°F 68% 1018 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
10:00

WNW
WNW

 7 / 8 mph 54 / 51°F 58% 1018 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

WNW
WNW

 7 / 9 mph 58 / 56°F 56% 1016 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 2%
Most Significant Cloud Type: high
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

WNW
WNW

 15 / 17 mph 55 / 51°F 68% 1015 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
19:00

W
W

 10 / 12 mph 53 / 50°F 78% 1015 mb
Low level cloud: 8%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: low
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

WSW
WSW

 6 / 8 mph 51 / 49°F 83% 1015 mb
Low level cloud: 46%
Mid level cloud: 61%
High level cloud: 0%
Most Significant Cloud Type: low
67%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust		Temp/
Feels Like		HumidityPressureCloud AmountPrecip AmountWeather
Wed 11
Feb		04:00

SE
SE

 10 / 12 mph 49 / 45°F 86% 1007 mb
Low level cloud: 97%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.0 In
10:00

NE
NE

 15 / 21 mph 51 / 46°F 76% 1011 mb
Low level cloud: 3%
Mid level cloud: 23%
High level cloud: 100%
Most Significant Cloud Type: medium
35%
0.0 In
16:00

SW
SW

 9 / 14 mph 56 / 53°F 56% 1013 mb
Low level cloud: 14%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: low
23%
0.0 In
22:00

NW
NW

 4 / 6 mph 53 / 52°F 84% 1019 mb
Low level cloud: 8%
Mid level cloud: 99%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
Thu 12
Feb		04:00

NE
NE

 16 / 28 mph 47 / 41°F 87% 1013 mb
Low level cloud: 85%
Mid level cloud: 11%
High level cloud: 3%
Most Significant Cloud Type: low
88%
0.0 In
10:00

N
N

 4 / 5 mph 60 / 60°F 59% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
16:00

WNW
WNW

 7 / 11 mph 61 / 61°F 59% 1023 mb
Low level cloud: 0%
Mid level cloud: 15%
High level cloud: 29%
Most Significant Cloud Type: medium
16%
0.0 In
22:00

NW
NW

 7 / 12 mph 55 / 54°F 78% 1024 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 99%
Most Significant Cloud Type: medium
9%
0.0 In
Fri 13
Feb		04:00

W
W

 7 / 13 mph 52 / 50°F 83% 1020 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 100%
Most Significant Cloud Type: medium
11%
0.0 In
10:00

NW
NW

 2 / 4 mph 53 / 54°F 74% 1025 mb
Low level cloud: 48%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: low
47%
0.0 In
16:00

WNW
WNW

 13 / 24 mph 56 / 52°F 62% 1020 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 18%
Most Significant Cloud Type: high
18%
0.0 In
22:00

NNE
NNE

 5 / 8 mph 57 / 57°F 80% 1019 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 13%
Most Significant Cloud Type: high
13%
0.0 In
Sat 14
Feb		04:00

NNW
NNW

 4 / 7 mph 44 / 42°F 75% 1018 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 99%
Most Significant Cloud Type: medium
50%
0.0 In
10:00

E
E

 4 / 7 mph 55 / 54°F 82% 1014 mb
Low level cloud: 25%
Mid level cloud: 79%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.0 In
16:00

S
S

 6 / 11 mph 60 / 60°F 60% 1012 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 32%
Most Significant Cloud Type: medium
25%
0.0 In
22:00

SSE
SSE

 16 / 27 mph 51 / 46°F 80% 1009 mb
Low level cloud: 44%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
52%
0.0 In
Sun 15
Feb		04:00

SSE
SSE

 9 / 17 mph 48 / 44°F 89% 1009 mb
Low level cloud: 98%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.9 In
10:00

S
S

 20 / 36 mph 51 / 44°F 89% 1005 mb
Low level cloud: 87%
Mid level cloud: 56%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.6 In
16:00

SSE
SSE

 11 / 22 mph 57 / 55°F 92% 1004 mb
Low level cloud: 97%
Mid level cloud: 100%
High level cloud: 100%
Most Significant Cloud Type: low
100%
1.5 In
22:00

WSW
WSW

 6 / 13 mph 52 / 50°F 79% 1009 mb
Low level cloud: 45%
Mid level cloud: 59%
High level cloud: 0%
Most Significant Cloud Type: low
66%
0.1 In
Mon 16
Feb		04:00

SSW
SSW

 3 / 7 mph 51 / 51°F 72% 1008 mb
Low level cloud: 38%
Mid level cloud: 21%
High level cloud: 3%
Most Significant Cloud Type: low
46%
0.3 In
10:00

SW
SW

 15 / 32 mph 51 / 46°F 74% 1009 mb
Low level cloud: 51%
Mid level cloud: 13%
High level cloud: 29%
Most Significant Cloud Type: low
58%
0.2 In
16:00

SSW
SSW

 9 / 20 mph 53 / 50°F 72% 1006 mb
Low level cloud: 79%
Mid level cloud: 69%
High level cloud: 99%
Most Significant Cloud Type: low
100%
0.2 In
22:00

W
W

 12 / 26 mph 47 / 41°F 74% 1008 mb
Low level cloud: 18%
Mid level cloud: 79%
High level cloud: 0%
Most Significant Cloud Type: medium
100%
0.3 In
Tue 17
Feb		04:00

W
W

 7 / 14 mph 47 / 44°F 85% 1010 mb
Low level cloud: 7%
Mid level cloud: 13%
High level cloud: 0%
Most Significant Cloud Type: low
11%
0.3 In
10:00

NNW
NNW

 5 / 10 mph 49 / 47°F 68% 1016 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 0%
Most Significant Cloud Type: medium
6%
0.1 In
16:00

NW
NW

 21 / 43 mph 47 / 39°F 58% 1015 mb
Low level cloud: 17%
Mid level cloud: 29%
High level cloud: 0%
Most Significant Cloud Type: low
27%
0.0 In
22:00

NNE
NNE

 4 / 9 mph 53 / 52°F 79% 1020 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 0%
Most Significant Cloud Type: high
0%
0.0 In
Wed 18
Feb		04:00

NW
NW

 12 / 25 mph 45 / 39°F 66% 1023 mb
Low level cloud: 0%
Mid level cloud: 9%
High level cloud: 32%
Most Significant Cloud Type: medium
10%
0.0 In
10:00

NNE
NNE

 4 / 8 mph 52 / 52°F 68% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 1%
Most Significant Cloud Type: high
1%
0.0 In
16:00

NNW
NNW

 4 / 8 mph 53 / 52°F 50% 1026 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 22%
Most Significant Cloud Type: medium
30%
0.0 In
22:00

NNW
NNW

 6 / 13 mph 53 / 51°F 68% 1022 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 7%
Most Significant Cloud Type: high
7%
0.0 In
Thu 19
Feb		04:00

N
N

 6 / 12 mph 48 / 46°F 72% 1029 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 99%
Most Significant Cloud Type: medium
8%
0.0 In
10:00

NE
NE

 5 / 11 mph 53 / 52°F 54% 1022 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 13%
Most Significant Cloud Type: medium
2%
0.0 In
16:00

NE
NE

 1 / 2 mph 62 / 62°F 57% 1027 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 12%
Most Significant Cloud Type: medium
3%
0.0 In
22:00

NNE
NNE

 4 / 7 mph 58 / 58°F 67% 1020 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
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