Remote measurements of the Tapera fire have provided an unprecedented look at the physical properties of a free-burning wildland fire. Although the mean radiometric temperature, determined from radiances at 1.6 and 3.9 m, varied only by 128 K across six successive overflights, spatial variation in temperature was much greater: 95 percent of all spatial measurements spanned a range of ca. 600 K. In comparison with fire-line temperature, radiant-flux density, a measure of fire intensity, showed greater variability from regions of actively spreading fire lines to the fire's trailing flank and across the width of some actively spreading fire runs. Fire was observed to spread along vectors with the wind at velocities of up to 0.74 m/s. Fire radiant-flux density was well correlated with the measured radiance of the fire at 3.9-m wavelength; measurements at that single wavelength could be used to map important features of fire behavior. Remote sensing methodology first applied at the Tapera fire is expected to have wide application for understanding the behavior and environmental effects of wildland fires.