30 
Introduction; Seasons and Winds. 
are July, August and September. June is also a fine month, though somewhat 
more rain falls than in October, when the returning N. W. Monsoon, the true 
rainy wind, can hardly have commenced to blow home. The wettest months 
of the year are from November to March, inclusive, when the N. W. Monsoon 
is in force. It has been stated that while Borneo south of the equator is having 
its rainy season under this wind, the parts of the island north of the equator, 
over which the N. E. Monsoon is blowing, are fine; but this is not altogether 
true. The great w^estern projection of the island upon which Sarawak (near its 
north coast), Sinkawang (west coast), Pontianak (south coast) are situated, receives 
its heaviest amount of wet at the same time as South Borneo. This is also the 
case at Sintang far inland a little north of the equator. The N. E. Trade-wind 
does not blow in force right down to the equator, and, when the N. W. Mon- 
soon is going on in the islands south of the equator , an indraught of the de- 
fiected N. E. wind must needs take place. In the South China Sea in the 
islands of Bintang, etc. this deflected wind is felt for half the year as a pre- 
vailing North wind (see, p. 32), and, no doubt, as such, or even as a N. W. 
wind, it passes over Borneo a little north of the equator, bringing with it great 
quantities of moisture from the China Sea. 
In Northern Borneo the seasons vary much according to locality. Dr. de 
Hollander speaks of the S. AV. (April — October) as the rainy monsoon, and 
the N. E. (October— April) as the fine one, and so also the Sailing Directory 
of the Indian Archipelago; but there is much to take exception at in these 
statements. In an article on the climate of British North Borneo by Mr. Robert 
H. Scott (Journ. R. Met. Soc. 1889, pp. 200—219), to which Dr. van der Stok 
has kindly called our attention, it is stated that “the true wet season occurs at 
Sandakan (on the N. E. coast) in the N. E. Monsoon, and includes the months 
of November, December and January, and generally part of October or Eebruary 
or both . . . The true dry season immediately follows this true wet season, and 
includes March and April, and generally the whole of May and part of Eebru- 
ary . . . This true dry season is followed by a period of moderate rainfall, 
commencing generally about June. The first month or six weeks of this period 
almost deserves to be called a second wet season, and the rest of the period 
up to the commencement of the true wet season might be described as the 
second dry season”. With these variations, the actual figures taken at Sandakan 
and Kudat show that by far the larger half of the total rainfall is deposited 
during the N. E. Monsoon, which is not to be wondered at, seeing that these 
places then present a windward shore to the Monsoon passing over the 
Sooloo Sea. 
At Labuan, the average for 1 1 years shows that the first four months of 
the year — the closing ones of the N. E. Monsoon — are the driest. 
The following tables are taken from those of Dr. van der Stok (Regen- 
waarnemingen in Ned. Ind. 1895, 416, 417), and Scott, I. c. (the inches 
of the latter converted to mm). 
