A.     Weather and Climate:

Vigan, like the rest of Ilocos region, undergoes two distinct seasons, the dry season and the wet season. The dry season normally commences from November to April reaching its peak during the torrid months of April and May. The wet months are from July to September, with the month of August as the wettest period. Normally, the average annual rainfall is 228.82 centimeters. The average annual maximum temperature is 30.9 °C, whereas the average annual minimum temperature is 23.2 °C. The average relative humidity is 81 %

B.      The Mestizo River

The Mestizo River played an important role in the development of trade and human activities in Vigan during the 15^th to the 19^th centuries. The river’s waterways were open to small watercrafts while its was used as berth by larger sea crafts. In those times, sea and river transport systems were used.

A 16^th century indicates that Vigan used to be completely surrounded by water that separated it from the mainland like a triangular-shaped island. Geological observations confirmed this because the bodies of water surrounding Vigan were traced to have been the main channels of the Abra River in those times when the river was then flowing in a westerly direction and branched as the river dissected the Vigan ridge.

A brief study was carried out to gather preliminary geological information necessary for the plan of rejuvenating and developing the Mestizo River. The geologist of the National Museum estimated that from the mouth of the river to the bridge of Caoayan with a distance of about 2.5 kilometers long, a width of 90 meters and at a depth of 2 meters, the volume of sediments to be dredged is approximately 450,000 cubic meters.

C.      Functional Role of the Municipality

As a capital town of the Province  of Ilocos Sur and situated at the center of at least five municipalities, the Municipality of Vigan is definitely a growth center. Vigan is the political, commercial, educational and religious center of center of Ilocos Sur. As it is the seat of the provincial government, most of the agencies of the National Government     hold their provincial offices in the municipality. People from adjacent municipalities come to Vigan for secondary to tertiary health services, and for their secondary and higher education. Merchants from different towns come to the market daily to sell their products and others come to Vigan to buy some of their daily needs. Vigan shall continue to be the leading municipality in the province, and has been upgraded to a First Class Municipality as of 1997.

With its historical attractions and beautiful beaches, the municipality is also becoming a tourist destination. Vigan has been identified as and is going to be developed as a major tourist destination under the National and Regional Tourism Master Plans, and the North Luzon Growth Quadrangle Development Plan. Under a grant of UNESCO, a dossier on Vigan is currently being prepared for its nomination to the prestigious UNESCO World Heritage list of Cultural Properties.

D.   Location and Land Area

Situated along the western coast of Northern Luzon, Vigan, the capital town lies in the northwestern part of the Province of Ilocos Sur. It is bounded on the north by the Municipality of Bantay, on the east by the Municipality of Santa, on the south by the Municipality of Caoayan, on the west by the Municipality of Sta. Catalina, and the southwest by China Sea. It is 408 kilometers north of the City of Manila, 80 kilometers from Laoag City and 139 kilometers from San Fernando, La Union, the government center of Region I.

It has an approximate land area of 2,740 hectares or 27.4 square kilometers which represent 1.06 percent of Ilocos Sur land area, divided among thirty nine (39) barangays, of which 9 barangays are classified as urban (created under P.D. No.86) and 30 barangays are classified as rural areas. Of which 60.68% are agricultural; 32.92% are residential; 0.55% is industrial; 1.93% is commercial and 0.91% is institutional. The rest are classified as open spaces, forest reserves, recreational and fishponds. The municipality has intermixture of land uses. Industrial district is intermixed with residential, institutional, commercial and agricultural districts.

Geological Base and Mineral Resources 

Sedimentary and metamorphic rocks are alluvium, fluviatile, lucustine, paludal, and beach deposits, raised coral reefs, atolls and beach rock. These are predominantly found along the coastal areas of Vigan. A very important non-metallic mineral resource that is found in Vigan is a kind of clay used in making earthen jars locally called "burnay".

E.       Fishing and Marine Resources

West of the municipality is the China Sea, where the people of the coastal barangays of Mindoro and San Pedro are engaged in fishing. Different species of salt-water fish such as "tuna", "mackerel", "siganid", "snappers", "buslogan", "lapu-lapu", "sungayan", "pusit", "laki", "baraniti" and others abound in the sea.

Fishponds producing milkfish or "bangus", "malaga", "tilapia", and shellfish such as "padaw" and "arimbukeng" consist of 24.4 hectares.

F.       Transportations

Air Transportation

A secondary airport called Mindoro Airport is located at Brgy. Mindoro. It has one asphalted runway, 900 meters long and 30 meters wide. At present, only chartered and private planes use it. The airport is a sleeping asset of the municipality for it does not, in any way, generate revenue. Plans have been made for the expansion and commercialization of said airport to attract tourist and to enlighten the boredom of coming to Vigan from Manila and some other parts of the Philippines. 

Land Transportation

Vigan has sufficient transport system. There are four Bus Companies operating within the vicinity of Vigan such as: Philippine Rabbit Bus Line, Dominion Bus Corp., Partas Trans. Co. and Aniceto Transportation. They operate direct bus services from Vigan to Manila, Baguio, Laoag and other parts of Luzon. 

Mode of Transport

Mode of transport within the municipality is purely land base. Vehicles for public use include jeepneys, tricycles and calesas.     

Buses, Mini-buses and jeepneys provide transportation to places outside Metro Vigan. The Metro Vigan transport system is serviced by tricycles, which were color-coded for purposes of identifying the municipality to which they belong. The tricycle number is permanently attached on top of the side car specified by different colors; green for Vigan, red for Bantay, yellow for Caoayan, orange for San Vicente and blue for Sta. Catalina.

A horse drawn vehicle, locally called "calesa" is also servicing the locality. It is an ideal transportation for sightseers particularly tourist.

G.   Topography  

Vigan’s terrain is generally flat. A flat slope of 15 degrees is found in Brgy. VII (Pagburnayan), Tamag and Paoa. The hills are already denuded.

The Mestizo River, a tributary of the Abra River, divides the municipality into two as it passes from north to south, east of the poblacion.