Frequency of Tropical Cyclone

Nine of the 20 tropical cyclones entering the Philippine Area of Responsibility (PAR) affect directly the province of Ilocos Norte. Most of these occur during the wet season. On the average, about 3 cyclones each occurred in the months of July and August, and one each in the months of June, September, and October. Higher probabilities of tropical cyclones occur from June to October with the highest probability occurring during the month of August. This coincides with the highest rainfall also occurring during that time.

Frequency of tropical cyclones in Ilocos Norte (1981-2020).*

*Source: PAGASA-Laoag City
Taken from PAGASA Laoag Synoptic Station
TD - Tropical Depression ( > 62 kph)
TS - Tropical Storm (62-88 kph)
STS – Severe Tropical Storm (89-117 kph
TY - Typhoon (118-220 kph)
STY - Super Typhoon (< 222 kph)

PSSW #1 - winds of 30-60 kph maybe expected in at least 36 hrs or intermittent rains maybe expected within 36 hrs
PSSW #2 - winds of 61-120 kph maybe expected in at least 24 hrs
PSSW #3 - winds of 121-170 kph maybe expected in at least 18 hrs
PSSW #4 - winds of 171-220 kph maybe expected in at least 12 hrs
PSSW #5 – winds of more than 220 kph maybe expected in at least 12 hrs