High Quality Content by WIKIPEDIA articles! A pressure system is a region of the Earth`s atmosphere where air pressure is a relative peak or lull in the sea level pressure distribution. The surface pressure at sea level varies minimally, with the lowest value measured 870.0 hectopascals (25.69 inHg) and the highest recorded 1,085.7 hectopascals (32.06 inHg). High- and low-pressure systems evolve due to interactions of temperature differentials in the atmosphere, temperature differences between the atmosphere and water within oceans and lakes, the influence of upper-level troughs and shortwaves, as well as the amount of solar heating or radiational cooling an area receives. Pressure systems cause the day-to-day weather experienced locally. Low-pressure systems are associated with clouds and precipitation that minimize temperature changes through the day, whereas high-pressure systems normally associated with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day. Pressure systems are analyzed by those in the field of meteorology within surface weather maps.