Measurements of the drift velocities of electrons and holes as functions of electric field and temperature in high-purity n- and p-type silicon with < 100 > lattice orientation are presented. The measurements cover electric held values between 2.5 and 50 kV/cm and temperatures between 233 and 333 K. For both electrons and holes differences of more than 15\%, are found between our < 100 > results and the < 111 > drift velocities from literature, which are frequently also used for simulating < 100 > sensors. For electrons, the < 100 > results agree with previous < 100 > measurements; however, for holes differences between 5 and 15\% are observed for fields above 10 kV/cm. Combining our results with published data of low-held we derive parametizations of the drift. velocities in high-ohmic < 100 > silicon for elections and holes for fields up to 50 kV/cm, and temperatures between 233 and 333 K. In addition, new parametrizations for the drift velocities of ell:irons and holes are introduced, which provide somewhat. better descriptions of existing data for < 111 > silicon than the standard parametrization. (C) 2015 Elsevier B.V. All rights reserved.