Porto Velho, Brazil · UTC-4 ☆

Porto Velho is in the America/Manaus timezone (AMT/UTC-4), with no daylight saving time observed. Porto Velho grew up around a railroad. The Madeira-Mamoré Railway, built between 1907 and 1912 at enormous human cost, was intended to bypass the Madeira River falls and connect Bolivia’s rubber-producing interior to the Amazon river system. Thousands of workers died during construction, earning it the name “Devil’s Railway.” The line never reached its full commercial potential and was largely abandoned by the 1970s.

Brazil has multiple timezones, and Porto Velho sits in Amazon Time, UTC-4, year-round without daylight saving. This contrasts with the Acre timezone to the west (UTC-5) and places Porto Velho on the same clock as Manaus to the east and much of the Brazilian interior.

the river, dams, and Amazonian forest

The Madeira River at Porto Velho is one of the Amazon’s most powerful tributaries. The Santo Antônio and Jirau hydroelectric dams, built in the early 2010s, flooded vast areas of forest and displaced thousands of people. The river’s energy now runs the region’s clocks in a more literal sense.

Porto Velho sits at 8 degrees south, just into the Southern Hemisphere, tropical and wet. The wet season runs roughly from November to April, bringing flooding to the low riverside areas. The dry season months of July and August see temperature and fires in the surrounding Amazonian forest.

9am in Porto Velho is 1pm in London.

Sources

• IANA Time Zone Database - America/Manaus
• Government of Rondônia