Of the four deaths, one was reported in the capital.
At least 959 dengue patients were hospitalised in the 24-hour period, according to data from the Directorate General of Health Services (DGHS).
Dengue has so far claimed at least 1,610 lives this year and nearly 310,046 were infected, making this the deadliest year since the first recorded epidemic in 2000.
According to DGHS data, 3,567 dengue patients were undergoing treatment at different hospitals across the country.
A total of 304,869 patients have so far been released from hospitals across the country this year.