Astroclimatology of Paranal

Air Pressure at Paranal

Pressure (mb)	Min	Ave	Max	Rms	nr. samples
day+night	731	743	749	2.5	5576
dark time	731	743	748	2.4	2553
24h change	0	10	63	1	4800

Statistics of atmospheric pressure at 2m above ground at Paranal (Sep.89-Sep90, hourly averages). The absolute pressure gradient is lower than 0.45mb/hour 80% of the time (95 percentile at 0.6mb/hour). The nighttime average pressure gradient is -0.2mb/hour.