With a vulnerability index of 10-30%, all the 39 barangays of the City are vulnerable to El Nino and La Nina phenomenon. Aside from these phenomena, the City also experiences series of tropical depression and storms over its geographical zone. It is noted that Alaminos City had a recorded frequency of tropical cyclone passage at an average of 20 cyclones in 12 years or 5 cyclones in 3 years. Corollary to this, the City had also observed a range of maximum gustiness during the passage of the tropical cyclones from 1948 - 1995, that ranges from 151- 200 KPH. These destructive winds could cause economic damages within the built-up areas and to various agricultural crop as well.
Based on the result of the study conducted by the Provincial Planning and Development Office, it is estimated that there are 13,238 hectares of about 86.88% of the City’s total land area that is susceptible to flooding. Of this, about 2,933 has is very susceptible, 6,186 has is moderately susceptible and 4,118 that is low susceptible. With regards to rain-induced landslide, about 143 has is moderately susceptible and low susceptibility accounts about 705 has. Meanwhile, 1,796 has is susceptible to storm surge which is broken down as follows: highly susceptible (276.94 has), moderately susceptible (81.69 has) and low susceptible at 1,438.27 has. Should there will be a tsunami with a wave height of seven meters at the coastal, all the 10 coastal barangays will be severely affected. The same report also shows that no barangays will be affected by a natural landslide (Indices of Disaster and Natural Hazards)