There were 5,857 new Covid-19 cases and 55 more fatalities registered during the previous 24 hours, the Public Health Ministry reported on Wednesday morning.
There were 5,629 cases in the general population and 228 among prison inmates.
The number of new cases rose from 5,126 announced on Tuesday, when the country recorded 53 more deaths.
On Tuesday, 7,318 Covid-19 patients were discharged from hospitals after recovering from the coronavirus.
Since April 1, when the third wave of Covid-19 began, Thailand has treated 2,053,129 Covid-19 patients, 1,952,445 of whom have recovered to date.
Since the pandemic started early last year, there have been 2,081,992 Covid-19 cases, with 1,979,871 complete recoveries so far.
The death toll stood at 20,450 during the third wave and 20,544 since the beginning of the pandemic.
Sumanee Wacharasin, hazard communication director of the Department of Disease Control, said the 55 latest fatalities were between the ages of 42 and 100 years.
They included four bed-ridden people who caught the disease from minders or relatives. Of the new fatalities, 41 (75%) had not been vaccinated, she said.
Bangkok recorded 13 more deaths while a further six were reported in the adjacent provinces of Samut Prakan (3) and Pathum Thani (3).
Other central plain provinces further from the capital recorded nine more deaths - in Ratchaburi (5), Rayong (2), Kanchanaburi (1) and Ayutthaya (1).
The South reported 18 more deaths – in Pattani (3), Nakhon Si Thammarat (3), Satun (2), Phatthalung (2), Phuket (2), Songkhla (1), Yala (1), Surat Thani (1), Chumphon (1), Phangnga (1) and Ranong (1).
The North saw nine fatalities – in Phitsanulok (3) Chiang Rai (1), Chiang Mai (2), Kamphaeng Phet (1), Nakhon Sawan (1) and Nan (1).
The 5,857 new cases included 5,618 local infections and 11 imported cases. Of the local infections, 5,349 were confirmed at hospitals and 269 via mass testing.
Bangkok had 734 new cases, followed by 426 in Songkhla, 290 in Nakhon Si Thammarat, 245 in Chiang Mai, 237 in Surat Thani, 235 in Samut Prakan, 205 in Chon Buri, 177 in Pattani, 140 in Yala and 129 in Trang.
“New cases are declining overall … including those in Greater Bangkok,” Dr Sumanee said.
However, officials were closely monitoring the situation in 13 provinces where new cases were steadily occurring.
She said Songkhla, Trang, Surat Thani, Krabi, Nakhon Si Thammarat, Khon Kaen, Sa Kaeo and Nakhon Ratchasima each had more than 100 new cases a day, while Saraburi, Ubon Ratchathani, Udon Thani, Kanchanaburi and Prachuap Khiri Khan each reported 80-100 new cases a day.
Phrae and Amnat Charoen had no new cases over the past 24 hours.
The 11 imported cases were from Austria (2), Germany (1), Russia (1), Laos (1), Singapore (1), France (1), Malaysia (3) and the Netherlands (1).
Since the country reopened to visitors on Nov 1, 94,756 people had arrived by air and 126 of them (0.13%) were diagnosed with Covid-19, as of midnight.
On Tuesday 81,577 people received Covid-19 treatment at hospitals (down from 83,093), including 1,529 seriously ill patients (down from 1,535) and 358 dependent on ventilators (down from 363).
Global Covid-19 cases rose by 553,076 in 24 hours to 259.01 million. The worldwide death toll went up by 7,603 to 5.18 million.
The United States had the most cases at 48.83 million, up 86,016, and the most deaths at 796,319, up 1,237.
