BarometerA barometer is a scientific instrument used to measure air pressure. Pressure tendencycan forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis to help find surface troughs, high pressure systems and frontal boundaries.AnemometerAn anemometer is a device used for measuring wind speed, and is also a common weather station instrument. The term is derived from the Greek word anemos, which means wind, and is used to describe any wind speed instrument used in meteorology.Weather VaneA weather vane, wind vane, or weathercock is an instrument for showing the direction of the wind. It is typically used as an architectural ornament to the highest point of a building. The word vane comes from the Old English word fana meaning "flag".HygrometerA hygrometer is an instrument used to measure the amount of humidity and water vapor in the atmosphere, in soil, or in confined spaces.ObservationObservation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the recording of data via the use of scientific instruments. The term may also refer to any data collected during the scientific activity.