Surface wind characteristics inside mature Tropical Cyclones (TC) over the Western North Pacific (WPAC) are analyzed using in-situ observations from the Impact of Typhoons on the Ocean in the Pacific (ITOP 2010) field program. Surface wind speeds obtained from the Stepped Frequency Microwave Radiometer (SFMR) and GPS dropwindsondes were used to calculate four surface wind variables lowest 150 m average wind speeds (WL150), Vsfc, 10-m interpolated wind speed, and SFMR surface wind speeds. Regression analysis is used to establish the consistency for each measured value to estimate the one-minute averaged surface wind speed. Results compared favorably to those computed for large data sets obtained in TCs over the Atlantic. These comparisons support and validate the accuracy of the SFMR wind speed measurements in the WPAC.