The main purpose of the Farmers' Assistance and Immediate Disaster Relief Act is to improve the process for determining eligibility for indemnity payments related to hurricane damage under the Hurricane Insurance Protection-Wind Index endorsement. This legislation aims to ensure that farmers receive timely and accurate assistance when their crops are affected by hurricanes. Key provisions of this act include a requirement for the Secretary of Agriculture to use specific data sets when assessing whether a county qualifies for indemnity payments after a hurricane event.