I. In unusual circumstances requiring prompt attention and for the purpose of developing or altering a growth management process under RSA 674:22, or a master plan or capital improvement program, a city, town, or county in which there are located unincorporated towns or unorganized places may adopt an ordinance imposing interim regulations upon development as provided in this section.

 
    II. An interim regulation may be proposed by the planning board if it determines that the requirements of paragraph I exist and makes findings of fact so indicating. Any such proposal shall be submitted to the local legislative body as a zoning ordinance and shall be subject to all procedures and provisions relative to enactment of zoning ordinances except that:

       (a) There shall be at least one hearing on the interim regulation held by the planning board at which parties in interest and citizens shall have an opportunity to be heard. At least 10 days' notice of the time and place of the hearing shall be published in a paper of general circulation in the municipality, and a legal notice of the hearing shall also be given in accordance with RSA 675:7. The notice shall include either the text or an adequate statement of the proposed regulation. After the hearing, the planning board, by vote, shall determine the final form of the regulation to be submitted to the local legislative body, which form of regulation shall conform, in substance, to the initial proposal and may include editorial revisions and textual modifications resulting from the public hearing which the planning board votes to adopt.

       (b) The local legislative body shall act upon the proposed interim regulation not later than 90 days after the posting of the notice for the public hearing under subparagraph (a).

    III. An interim regulation adopted under this section shall expire at the earliest of the following occurrences: one year after its adoption by the local legislative body; such earlier time as specified in the ordinance; or upon the effective date of an ordinance adopted under RSA 674:22 which addresses the unusual circumstances.