Editing Weather station (section)

==Weather instruments==
[[File:NOAA weather station at Wake Island harbor.jpg|thumb|The [[National Oceanic and Atmospheric Administration|NOAA]] weather station at [[Wake Island]] harbor measures and transmits data on [[wind speed]], [[atmospheric pressure]], [[temperature|air temperature]] and [[tide]]s.]]
{{main|Weather instrumentation}}
{{further|List of weather instruments}}
A weather instrument is any device that measures weather related conditions. Since there are a variety of different weather conditions, there are a variety of different weather instruments.  

Typical weather stations have the following instruments and sensors:

* [[Thermometer]] for measuring air and sea surface temperature
* [[Barometer]] for measuring [[atmospheric pressure]]
* [[Hygrometer]] for measuring humidity
* [[Anemometer]] for measuring wind speed
* [[Pyranometer]] for measuring [[solar radiation]]
* [[Rain gauge]] for measuring liquid precipitation over a set period of time.
* [[Wind sock]] for measuring general wind speed and wind direction
* [[Wind vane]], also called a weather vane or a weathercock: it shows which way the wind is blowing.
* [[Pan evaporation|Evaporation pan]] for measuring evaporation.

In addition, at certain [[automated airport weather station]]s, additional instruments may be employed, including:

* [[Present weather sensor]] for identifying falling precipitation
* [[Disdrometer]] for measuring [[Raindrop size distribution|drop size distribution]]
* [[Transmissometer]] for measuring visibility
* [[Ceilometer]] for measuring cloud ceiling

More sophisticated stations may also measure the [[ultraviolet index]], [[leaf wetness]], [[soil moisture]], soil temperature, water temperature in ponds, lakes, creeks, or rivers, and occasionally other data.

===Exposure===
[[File:2008-07-01 Elko ASOS viewed from the south cropped.jpg|thumb|right|[[Automated Surface Observing Station|Automated Surface Observing Stations]] are the source of the most commonly cited weather reports in the United States, located at airports in all major cities and most smaller ones]]
Except for those instruments requiring direct exposure to the elements (anemometer, rain gauge), the instruments should be sheltered in a vented box, usually a [[Stevenson screen]], to keep direct sunlight off the thermometer and wind off the hygrometer. The instrumentation may be specialized to allow for periodic recording, otherwise significant manual labour is required for record keeping. Automatic transmission of data, in a format such as [[METAR]], is also desirable as many weather station's data is required for weather forecasting.