Agate has a Remote Access Weather Station (RAWS) that records hourly temperature, humidity, wind speed, maximum wind speed, wind direction, precipitation, and fuel stick temperature and moisture. Based on data from 1997 through 2002 (NPS 2002), Agate temperatures range from a maximum of 95°F. to 104°F. from June-August, to a December-February minimum of -5°F to -22°. The mean annual precipitation at the park is 10.91" with most of it falling from January to August, but during that period in 2002 only 5.85" were recorded. The prevailing winds are from the northwest, west, or southwest, but have been recorded from all other directions at various times. Maximum annual windspeeds of 43-50 mph occur from November through February, but 49-50 mph winds have been recorded in May. There is no reliable record for the wind being calm at any recorded time.
The Niobrara River valley and its included wetlands through the Agate Fossil Beds National Monument are incised some 250' below the surrounding tablelands. The prevailing northwesterly and westerly winds across these tablelands are often drier and warmer than the air down in the valley, resulting in local inversions that hold cool moist air in the valley. For example, from 1 October 2001 through 28 February 2002, Agate's daily RAWS-recorded humidity reached 100% 40 nights, about 25% of the time, with most of the humidity in October and November.
Last updated: April 10, 2015