WEATHER FOR BUSINESS

We supply weather data to businesses

Free Weather Plugin

Add this forecast to your website



Local Weather

Locarno 14 Day Long Range Forecast

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

Switzerland

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

For Locarno in the coming two weeks the average daytime maximum temperature will be around 24°C, with a high for the two weeks of 28°C expected on the afternoon of Tuesday 9th. The mean minimum temperature will be 10°C, dipping to its lowest on the morning of Wednesday 3rd at 7°C. Expect the coming 14 days to have some days seeing a little precipitation and some days with rain. The indicators are that Monday 1st will have the most precipitation with an accumulation of around 14.0mm. On the whole winds are likely to be light.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Mon 01
Sep
19:00

SW
SW

1 / 1 mph 59 / 59°F 99% 1012 mb
Low level cloud: 76%
Mid level cloud: 59%
High level cloud: 19%
Most Significant Cloud Type: low
98%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
22:00

ENE
ENE

1 / 1 mph 55 / 55°F 99% 1013 mb
Low level cloud: 80%
Mid level cloud: 47%
High level cloud: 32%
Most Significant Cloud Type: low
100%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
Tue 02
Sep
01:00

N
N

4 / 8 mph 54 / 53°F 97% 1013 mb
Low level cloud: 58%
Mid level cloud: 74%
High level cloud: 33%
Most Significant Cloud Type: low
87%
Expect 0.2 In of precipitation over the past 3 hours.
0.2 In
04:00

N
N

5 / 9 mph 51 / 49°F 96% 1011 mb
Low level cloud: 40%
Mid level cloud: 48%
High level cloud: 19%
Most Significant Cloud Type: low
59%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
07:00

N
N

5 / 9 mph 52 / 49°F 95% 1012 mb
Low level cloud: 35%
Mid level cloud: 30%
High level cloud: 32%
Most Significant Cloud Type: low
48%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
10:00

NNW
NNW

5 / 7 mph 67 / 65°F 74% 1012 mb
Low level cloud: 0%
Mid level cloud: 33%
High level cloud: 0%
Most Significant Cloud Type: medium
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

NNW
NNW

5 / 6 mph 72 / 69°F 60% 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
16:00

NNW
NNW

6 / 7 mph 72 / 69°F 59% 1011 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 7%
Most Significant Cloud Type: medium
24%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

N
N

6 / 12 mph 54 / 51°F 77% 1013 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 32%
Most Significant Cloud Type: medium
15%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

N
N

7 / 14 mph 49 / 47°F 78% 1015 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 15%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Wed 03
Sep
01:00

N
N

7 / 14 mph 48 / 44°F 78% 1016 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 6%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

N
N

7 / 14 mph 46 / 43°F 73% 1016 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 21%
Most Significant Cloud Type: medium
6%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

N
N

6 / 13 mph 48 / 45°F 67% 1016 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 5%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

S
S

3 / 3 mph 74 / 75°F 39% 1016 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 17%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

SSW
SSW

5 / 6 mph 77 / 76°F 38% 1016 mb
Low level cloud: 0%
Mid level cloud: 25%
High level cloud: 40%
Most Significant Cloud Type: medium
27%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SSW
SSW

4 / 4 mph 77 / 77°F 44% 1016 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
19:00

NNW
NNW

2 / 4 mph 58 / 56°F 79% 1017 mb
Low level cloud: 0%
Mid level cloud: 1%
High level cloud: 6%
Most Significant Cloud Type: high
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

N
N

5 / 11 mph 53 / 52°F 76% 1019 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 13%
Most Significant Cloud Type: medium
2%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Thu 04
Sep
01:00

NNE
NNE

5 / 11 mph 50 / 49°F 75% 1019 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 13%
Most Significant Cloud Type: high
13%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

NNE
NNE

5 / 11 mph 49 / 47°F 73% 1018 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 15%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NNE
NNE

5 / 10 mph 53 / 50°F 69% 1018 mb
Low level cloud: 0%
Mid level cloud: 12%
High level cloud: 56%
Most Significant Cloud Type: medium
14%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

S
S

3 / 3 mph 76 / 76°F 46% 1017 mb
Low level cloud: 0%
Mid level cloud: 22%
High level cloud: 33%
Most Significant Cloud Type: medium
23%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

S
S

5 / 5 mph 80 / 78°F 40% 1016 mb
Low level cloud: 0%
Mid level cloud: 24%
High level cloud: 32%
Most Significant Cloud Type: medium
25%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SSW
SSW

5 / 5 mph 79 / 78°F 46% 1016 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 4%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

N
N

1 / 2 mph 59 / 58°F 77% 1017 mb
Low level cloud: 0%
Mid level cloud: 29%
High level cloud: 100%
Most Significant Cloud Type: medium
33%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

N
N

4 / 9 mph 57 / 56°F 77% 1018 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 87%
Most Significant Cloud Type: medium
47%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Fri 05
Sep
01:00

NNW
NNW

8 / 15 mph 53 / 50°F 90% 1018 mb
Low level cloud: 12%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: medium
79%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

NNE
NNE

7 / 12 mph 50 / 47°F 96% 1019 mb
Low level cloud: 51%
Mid level cloud: 27%
High level cloud: 31%
Most Significant Cloud Type: low
64%
Expect 0.3 In of precipitation over the past 3 hours.
0.3 In
07:00

NNE
NNE

8 / 17 mph 48 / 44°F 93% 1021 mb
Low level cloud: 20%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
24%
Expect 0.1 In of precipitation over the past 3 hours.
0.1 In
10:00

N
N

6 / 6 mph 72 / 76°F 52% 1019 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
13:00

NNE
NNE

5 / 6 mph 78 / 77°F 40% 1018 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
16:00

NE
NE

5 / 6 mph 79 / 77°F 43% 1017 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
19:00

NNE
NNE

5 / 11 mph 58 / 56°F 74% 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
22:00

N
N

7 / 14 mph 51 / 49°F 77% 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
Sat 06
Sep
01:00

N
N

6 / 13 mph 49 / 46°F 76% 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
04:00

NNE
NNE

5 / 11 mph 47 / 44°F 65% 1021 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 33%
Most Significant Cloud Type: high
32%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NNE
NNE

4 / 9 mph 49 / 47°F 65% 1022 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 4%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

S
S

3 / 3 mph 72 / 76°F 46% 1021 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 11%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

S
S

5 / 5 mph 76 / 76°F 46% 1020 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 100%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SSW
SSW

5 / 5 mph 76 / 77°F 55% 1019 mb
Low level cloud: 0%
Mid level cloud: 6%
High level cloud: 33%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

NNW
NNW

1 / 3 mph 58 / 57°F 90% 1021 mb
Low level cloud: 1%
Mid level cloud: 5%
High level cloud: 100%
Most Significant Cloud Type: medium
11%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

NNE
NNE

4 / 8 mph 54 / 54°F 88% 1023 mb
Low level cloud: 1%
Mid level cloud: 5%
High level cloud: 52%
Most Significant Cloud Type: medium
10%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
Sun 07
Sep
01:00

NNE
NNE

4 / 9 mph 52 / 51°F 83% 1023 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 12%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
04:00

NNE
NNE

5 / 10 mph 51 / 49°F 79% 1023 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 33%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
07:00

NNE
NNE

4 / 9 mph 53 / 51°F 75% 1023 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 14%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
10:00

S
S

2 / 3 mph 76 / 77°F 53% 1022 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 7%
Most Significant Cloud Type: medium
3%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
13:00

S
S

4 / 5 mph 81 / 79°F 44% 1021 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 46%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
16:00

SSW
SSW

4 / 5 mph 81 / 80°F 53% 1020 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 15%
Most Significant Cloud Type: medium
4%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
19:00

N
N

3 / 6 mph 62 / 60°F 84% 1022 mb
Low level cloud: 0%
Mid level cloud: 2%
High level cloud: 88%
Most Significant Cloud Type: medium
5%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
22:00

N
N

5 / 11 mph 56 / 55°F 88% 1023 mb
Low level cloud: 1%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
7%
Expect 0.0 In of precipitation over the past 3 hours.
0.0 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Mon 08
Sep
01:00

NNE
NNE

4 / 9 mph 56 / 56°F 94% 1022 mb
Low level cloud: 23%
Mid level cloud: 22%
High level cloud: 0%
Most Significant Cloud Type: low
30%
0.0 In
07:00

N
N

5 / 10 mph 58 / 58°F 81% 1022 mb
Low level cloud: 0%
Mid level cloud: 10%
High level cloud: 0%
Most Significant Cloud Type: medium
9%
0.0 In
13:00

SSW
SSW

5 / 10 mph 85 / 85°F 41% 1021 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
19:00

N
N

2 / 5 mph 67 / 67°F 78% 1020 mb
Low level cloud: 0%
Mid level cloud: 11%
High level cloud: 35%
Most Significant Cloud Type: medium
12%
0.0 In
Tue 09
Sep
01:00

N
N

5 / 10 mph 57 / 56°F 76% 1018 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 5%
Most Significant Cloud Type: medium
46%
0.0 In
07:00

NNE
NNE

4 / 9 mph 59 / 59°F 73% 1017 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 2%
Most Significant Cloud Type: medium
7%
0.0 In
13:00

S
S

5 / 11 mph 80 / 81°F 53% 1014 mb
Low level cloud: 0%
Mid level cloud: 17%
High level cloud: 0%
Most Significant Cloud Type: medium
17%
0.0 In
19:00

N
N

2 / 4 mph 64 / 64°F 83% 1016 mb
Low level cloud: 0%
Mid level cloud: 5%
High level cloud: 0%
Most Significant Cloud Type: medium
4%
0.0 In
Wed 10
Sep
01:00

N
N

3 / 7 mph 59 / 59°F 86% 1016 mb
Low level cloud: 1%
Mid level cloud: 25%
High level cloud: 100%
Most Significant Cloud Type: medium
30%
0.0 In
07:00

NNE
NNE

4 / 9 mph 56 / 56°F 85% 1015 mb
Low level cloud: 0%
Mid level cloud: 14%
High level cloud: 0%
Most Significant Cloud Type: medium
14%
0.0 In
13:00

SSW
SSW

5 / 11 mph 76 / 79°F 63% 1014 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: medium
45%
0.0 In
19:00

N
N

3 / 6 mph 58 / 59°F 85% 1014 mb
Low level cloud: 0%
Mid level cloud: 42%
High level cloud: 89%
Most Significant Cloud Type: medium
45%
0.3 In
Thu 11
Sep
01:00

N
N

2 / 5 mph 57 / 58°F 95% 1014 mb
Low level cloud: 37%
Mid level cloud: 45%
High level cloud: 97%
Most Significant Cloud Type: low
64%
0.1 In
07:00

NE
NE

2 / 4 mph 55 / 55°F 92% 1016 mb
Low level cloud: 9%
Mid level cloud: 72%
High level cloud: 9%
Most Significant Cloud Type: medium
96%
0.2 In
13:00

WSW
WSW

2 / 5 mph 65 / 65°F 95% 1011 mb
Low level cloud: 54%
Mid level cloud: 57%
High level cloud: 89%
Most Significant Cloud Type: low
84%
0.3 In
19:00

N
N

3 / 7 mph 56 / 56°F 94% 1020 mb
Low level cloud: 18%
Mid level cloud: 62%
High level cloud: 16%
Most Significant Cloud Type: medium
100%
0.1 In
Fri 12
Sep
01:00

NNW
NNW

2 / 4 mph 63 / 63°F 99% 1012 mb
Low level cloud: 78%
Mid level cloud: 49%
High level cloud: 91%
Most Significant Cloud Type: low
100%
0.7 In
07:00

N
N

2 / 5 mph 54 / 55°F 95% 1022 mb
Low level cloud: 31%
Mid level cloud: 84%
High level cloud: 36%
Most Significant Cloud Type: low
64%
0.0 In
13:00

ESE
ESE

0 / 0 mph 65 / 65°F 95% 1010 mb
Low level cloud: 33%
Mid level cloud: 96%
High level cloud: 51%
Most Significant Cloud Type: medium
100%
0.2 In
19:00

NW
NW

1 / 2 mph 60 / 60°F 97% 1022 mb
Low level cloud: 46%
Mid level cloud: 30%
High level cloud: 4%
Most Significant Cloud Type: low
57%
0.0 In
Sat 13
Sep
01:00

N
N

2 / 4 mph 55 / 56°F 96% 1015 mb
Low level cloud: 38%
Mid level cloud: 95%
High level cloud: 47%
Most Significant Cloud Type: low
77%
0.5 In
07:00

N
N

3 / 7 mph 54 / 54°F 86% 1021 mb
Low level cloud: 1%
Mid level cloud: 44%
High level cloud: 21%
Most Significant Cloud Type: medium
47%
0.0 In
13:00

SSW
SSW

5 / 10 mph 68 / 68°F 76% 1017 mb
Low level cloud: 3%
Mid level cloud: 45%
High level cloud: 98%
Most Significant Cloud Type: medium
56%
0.1 In
19:00

SSW
SSW

2 / 4 mph 60 / 60°F 99% 1021 mb
Low level cloud: 83%
Mid level cloud: 44%
High level cloud: 82%
Most Significant Cloud Type: low
100%
0.0 In
Sun 14
Sep
01:00

N
N

2 / 5 mph 55 / 56°F 95% 1021 mb
Low level cloud: 40%
Mid level cloud: 48%
High level cloud: 16%
Most Significant Cloud Type: low
58%
0.0 In
07:00

NNE
NNE

3 / 7 mph 55 / 55°F 95% 1022 mb
Low level cloud: 26%
Mid level cloud: 86%
High level cloud: 100%
Most Significant Cloud Type: medium
100%
0.5 In
13:00

S
S

4 / 10 mph 72 / 76°F 76% 1021 mb
Low level cloud: 3%
Mid level cloud: 32%
High level cloud: 0%
Most Significant Cloud Type: medium
41%
0.1 In
19:00

N
N

4 / 8 mph 57 / 57°F 91% 1021 mb
Low level cloud: 4%
Mid level cloud: 20%
High level cloud: 21%
Most Significant Cloud Type: medium
32%
0.2 In
Mon 15
Sep
01:00

NNE
NNE

4 / 8 mph 53 / 52°F 93% 1022 mb
Low level cloud: 13%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: medium
82%
0.1 In
07:00

NNE
NNE

4 / 8 mph 54 / 54°F 86% 1019 mb
Low level cloud: 1%
Mid level cloud: 58%
High level cloud: 5%
Most Significant Cloud Type: medium
59%
0.0 In
13:00

S
S

5 / 11 mph 72 / 76°F 70% 1020 mb
Low level cloud: 4%
Mid level cloud: 28%
High level cloud: 22%
Most Significant Cloud Type: medium
38%
0.0 In
19:00

N
N

3 / 7 mph 57 / 57°F 93% 1019 mb
Low level cloud: 15%
Mid level cloud: 44%
High level cloud: 9%
Most Significant Cloud Type: medium
85%
0.0 In
Tue 16
Sep
01:00

ENE
ENE

2 / 4 mph 61 / 61°F 98% 1020 mb
Low level cloud: 68%
Mid level cloud: 82%
High level cloud: 4%
Most Significant Cloud Type: low
97%
0.4 In
07:00

N
N

5 / 10 mph 55 / 54°F 85% 1020 mb
Low level cloud: 0%
Mid level cloud: 20%
High level cloud: 0%
Most Significant Cloud Type: medium
19%
0.0 In
13:00

S
S

6 / 12 mph 74 / 77°F 59% 1016 mb
Low level cloud: 0%
Mid level cloud: 28%
High level cloud: 0%
Most Significant Cloud Type: medium
27%
0.0 In
19:00

N
N

3 / 6 mph 59 / 59°F 91% 1020 mb
Low level cloud: 3%
Mid level cloud: 31%
High level cloud: 32%
Most Significant Cloud Type: medium
38%
0.2 In

Other Locations Near to Locarno

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