A nightly curfew now starts at 10pm, while gyms and some sporting events are to be allowed, although bingo and contact sports remain prohibited.
Mass gatherings are limited to no more than 40 people indoors and 80 outdoors, while kava club meetups are restricted to groups no bigger than four.
Liquor licensed night clubs and bars are allowed to open from Wednesday to Saturday.
Tonga's border remains closed. The kingdom has no confirmed cases of covid-19 to date.