The CAMEX-4 Aerosonde dataset contains temperature, humidity, and atmospheric pressure measurements collected to study the boundary layer below levels where traditional hurricane reconnasissance aircaft fly. The Aerosonde is an unmanned aerial vehicle with a wingspan of 2.9 meters (~9 feet) weighing approximately 14 kg (~31 lbs). Carrying a payload of air pressure, temperature and humidity probes, the aircraft can fly at altitudes from near the surface to 21,000 feet at speeds of 50-95 mph for periods of up to 30 hours. Controlled by dual computers and navigated by GPS, the Aerosonde is designed to economically collect meteorological data over a wide area.