“The climate of western New Britain is what might be expected of a region of jungle-covered mountains and swamps. At all times during the year, the humidity is high, and the daytime temperature range hovers around 90 degrees; at night the temperature seldom drops below 72 degrees. The annual rainfall usually totals 150–200 inches and much of this, an average of 30 inches a month, comes during the period of the northwest monsoon, mid-December to mid-February. In this wettest season, rain may fall almost every day and squalls with torrential downpours are frequent. The northwest winds are strong and fairly steady, making the sea rough and the surf heavy. The dry season at Cape Gloucester occurs during the summer months when the prevailing southeast winds vent most of their force on the south slopes of the mountains. The periods between the two seasons, and the period of the southeast monsoon itself, are times of comparatively calm weather. The campaign to seize control of western New Britain would be fought in the worst possible weather of the year. Low-lying terrain would disappear beneath a cover of standing water, and, on the higher ground, the trees, the undergrowth, and the land itself would become and remain, rainsoaked. The prospect was that attacker and defender alike, mired in combat in the dripping jungle, would curse the day they set foot on the island.” – Henry I. Shaw, Jr., and Major Douglas T. Kane, USMC, Isolation of Rabaul , History of U.S. Marine Corps Operations in World War II, Vol.II, “Part IV, The New Britain Campaign”