MIL-HDBK-310, MILITARY HANDBOOK: GLOBAL CLIMATIC DATA FOR DEVELOPING MILITARY PRODUCTS (23 JUN 1997)., This handbook provides climatic data primarily for use in engineering analyses to develop and test military equipment and materiel. 1.1 Purpose. The data provided are intended to serve as natural environmental starting points for the sequence of engineering analyses to derive environmental design criteria for materiel. The climatic data are also intended toprovide guidance in the development of environmental tests of materiel.