During the latter part of the westerly monsoon, on that part of the coast between Cape Villaret and Point Swan, we found the weather remarkably fine, with the exception of an occasional short, but severe squall, from the eastward. During the day there was generally a moderate seabreeze between North-West and South-West commencing in the forenoon, and lasting sometimes nearly until midnight—on which occasions it blew strongest during the night); during the other part of the twenty-four hours the wind was light from the eastward or calm. Captain King experienced similar weather in August.
It was not until we had reached Point Swan, in latitude 16 degrees 20 minutes South that we experienced any of the bad weather that is usually met with, at this season of the year, a few degrees to the northward; it commenced in the last week of January, and continued until the middle of February, during which period, there were some strong gales from the westward, between North-West and South-West accompanied by heavy rain, thunder and lightning; but although there was a good deal of dirty weather, it was by no means constant, as there were occasional intervals of fine weather, with moderate westerly winds. This was the only bad weather on this part of the coast, during the season, that could be said to be caused by the westerly monsoon, if we except the East-South-East squalls, that do not occur in the easterly monsoon.
While this weather lasted, the easterly squalls were quite suspended, and the heavy bank of clouds that had generally been noticed in the South-East had dispersed for the time; but after the strong westerly winds had ceased, the weather was generally fine, and the wind mostly from some western point; there were occasional showers, and the clouds in the eastern horizon resumed their threatening appearance, bringing some hard squalls, and rain from that quarter. In the middle of March (being the time when equinoctial gales are looked for in most parts of the world) there were two or three days of squally, unsettled weather, with rain, that seemed to terminate the season of the westerly monsoon. After the 1st of April, the weather was invariably fine, and the easterly squalls had ceased to trouble us; land and seabreezes became regular, and the easterly monsoon had no doubt set in to the northward; the strongest breezes now were from South-East but, generally speaking, the winds were very light near the land.
It does not appear that the westerly monsoon blows with any degree of regularity, to the southward of the 13th degree of south latitude; although for some degrees south of that, the weather is influenced by it, and winds between West-North-West and South-West will be experienced, and from the appearances on many parts of the coast, there are no doubt strong gales at times from the westward, that send in a very heavy sea. During the easterly monsoon, the weather is fine on the North-West coast, particularly in the months of May, June, July, and August; this is undoubtedly the best time for visiting it; land and seabreezes are regular, and the temperature is very agreeable.