10
ON THE EASTERN COAST OF LUZON, IN THE EASTERN VISAYAS, AND EASTERN MINDANAO.
Millimeters of rainfall.
Stations.
June.
July.
August.
Septem-
ber.
October.
Total.
Per cent.
Haler . _ _- -
249. (i
339. 5
212.8
450.1
310.1
1,508. 1
41.0
83.8
90. 0
73. 9
116.5
239
009. 8
42. 1
Atimonan .. — — —. -- -
147.4
223. 3
195.1
298. 7
390. 1
1,200.0
47.0
I.egaspi . _ - - - -
200. 7
209. 9
159.1
298. 4
403. 4
1,271.5
40. 0
Albay _ ..
(iuhat _ -- --
207. (1
200. 2
242. 1
299. 8
212.5
1,228.2955. 0
41.5
114
130.3
99.5
270.2
341. 0
32. 9
I’alanoc, __
120. 7
127.9
129
284. 2
130.2
792
54. 8
Calbavog. _
154.0
191.4
159. 4
339
208. 0
1,113
49.5
Horongan _
249. 7
150. 2
140. 7
253. 8
344. 8
1,145.2
31.2
Oatbalogan-
129.4
85
182. 0
250. 8
218. 3
872.1
44.6
Tacloban _ . .
238
110.5
213.4
184
171
916.9
42.3
Ormoc _ _ __-.
190. 3
290. 3
290. 3
334.5
200. 0
1,378
01.0
Maasin. — — -
124.4
100.5
131.3
237. 5
157. 4
817.1
53.5
Surigao_____
55. 9
145. 3
77.4
145.8
222
(>4(>. 4
24.5
Tandag_ ___ -
104. 2
217.1
123. 7
187.4
198. 3
890. 7
20.1
I!utuan_. ___ _ -
140.2
123.9
73
145.4
100.5
055
32.8
(/iirn^n, .. .. __
80.4
142.7
75.7
H7. 4
128. 4
500. 0
20.4
Davao-
209. 7
240. 8
202. 3
149. 8
191.6
1,000.2
49.3
II. WINTER OR NORTHEAST MONSOON RAINFALL.
The winter rainfall in the Philippine Archipelago is due to the northeasterly air currents whicharc caused ]>v the Siberian center of high pressure extending over the Chinese Empire during themonths of November, December, January, and February. These winds necessarily reach our Archi-pelago richly laden with moisture, because they come from the Pacific Ocean. The result areabundant rains on the eastern coasts, which for these regions constitute a second rainy season, ofless importance, however, than the one during the summer and autumn months. Only in theeasternmost and coast stations the total rainfall during the winter months reaches 50 per cent of theannual amount. The winter rains are far from being continuous since, like the summer rains, theycome at intervals varying in frequency and duration. They follow not only the variations of thecontinental high pressure area, but also the barometric oscillations taking place over the southernregions of our Archipelago. Consequently the time of their setting in is very uncertain; sometimesisolated periods of northeast monsoon occur early in November, and even in October, while notunfrequently the first monsoons come late in the second half of December. Something similarhappens at the end of the season. Although the center of high pressure seems to advance towardeast-southeast during the months of January and February, and the winds in the Archipelagoveer dy to the east, vet. it is not unusual to have bursts of northeasters after the middle ofFebruary.
About the character and causes of the northers in the Philippine Archipelago we wrote in the“Climatological Notes” for the year 1903:
Generally, as lias already been mentioned, these “northers” are due to the advance of the China centerof high pressure toward our Archipelago. In this case the barometers rise extraordinarily in the northeast ofthe group and the winds acquire the force of a hard gale, accompanied by squalls of abundant rain. If thepressure continues to rise, the ell'eet of the northers extends as far as the western coasts, especially of Luzon.Thou the sky shrouds itself in heavy clouds and rain begins to fall at short intervals, the whole phenomenonconstituting what are known in these regions as “dirty northers.” The north and northeast winds retain theirviolence all along the eastern coasts of the Archipelago, down to Capo San Agustin, which is situated nearthe sixth parallel of north latitude, although, since the barometers of the Visayas and of ^Mindanao maintainthemselves at almost equal heights, there exists no appreciable gradient south of the thirteenth parallel.