Lomu, 40, died last week at his home in the city. Capped 63 times by his country, he was diagnosed with a rare kidney condition in 1995.
Monday's service will take place at Auckland's Eden Park stadium.
"Jonah touched people's lives across the country and around the world," wrote New Zealand Prime Minister John Key on his official website.
"This service will be open to all members of the public who want to remember the significant contribution Jonah made, not only to rugby here and overseas, but also to the wider community through his work with charities such as Unicef and Kidney Kids NZ."
A private funeral for Lomu will take place the following day.
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Former All Blacks coach John Hart has been acting as a spokesman for the Lomu family.
On Friday, he revealed more about Lomu's death, saying the former player had just returned home to Auckland after "a magic time" at the Rugby World Cup in England, which was won by the All Blacks.
Following a stopover in Dubai with his family, there had been no sign of any issues with his kidney condition when they arrived home, Hart said.
"He went to bed Tuesday night and he was fine, unfortunately when they awoke mid-morning they found him dead," Hart added.
A public memorial service for New Zealand great Jonah Lomu is to be held in Auckland next Monday.