The first fatality of the year, a 20-year-old man, died on Wednesday in the city-state, which is known for fastidious sanitation but is facing a spike in the breeding of the Aedes mosquito that transmits the disease.
More than 7,700 people were infected as of May 25 in Singapore, compared to 4,632 in all of 2012, according to data from the health ministry. The worst year on record was 2005, with 13,984 infections.
"This is the first dengue death case this year and it highlights the urgency for greater community vigilance to stamp out possible mosquito breeding spots," a government statement said late Thursday after the first death was confirmed.
Dengue is endemic in Singapore, a rainy tropical island, as well as neighbouring Southeast Asian countries.
The National Environment Agency said warmer weather from April to October was likely to lead to an increase in dengue cases as the Aedes mosquito and the dengue virus thrive during the hot season.
Weekly cases rose to 638 in the period ending May 25, nearing the all-time high of 713 cases in 2005, according to health ministry data.
Prime Minister Lee Hsien Loong launched a nationwide campaign last month, calling on 30,000 volunteers to fan out and eliminate mosquito breeding spots such as stagnant pools of water, garden pots and roof drains.
The World Health Organization (WHO) warned in January that the disease had global "epidemic potential" after registering a 30-fold increase in the last 50 years to two million cases annually due to climate change and increased travel.
Dengue causes high fever, headaches, itching and joint pains. At an advanced stage it can lead to haemorrhaging and death.
The illness affects between 50 million and 100 million people in the tropics and subtropics each year, according to the WHO.