Withstanding Extreme Agricultural Threats by Harvesting Economic Resilience Act of 2025 or the WEATHER Act of 2025This bill requires the federal crop insurance program (FCIP) to provide for the research and development of a single index insurance policy to insure against agricultural income losses due to covered weather conditions.Specifically, the FCIP must develop a single index policy that is available in every state, each U.S. territory, and the District of Columbia to insure against agricultural income losses due to one or more covered weather conditions. Covered weather conditions are those&nbsp;found to be closely correlated with agricultural income losses, including high winds, excessive moisture and flooding, extreme heat, abnormal freeze conditions, wildfire, hail, drought, and any other severe weather or growing conditions applicable to small-scale farmers.Under an index policy, claim payments are generally triggered based on a predetermined index that is entirely independent of the individual farm operation (e.g., rainfall level). Under such a policy, the payments are automatically triggered when the index reaches a certain level rather than when an insured farmer files a claim.&nbsp;In carrying out the research and development, the&nbsp;FCIP&nbsp;must hold stakeholder meetings to solicit producer and agent feedback.In addition, the FCIP must make publicly available a report on the results of the research and development, and any recommendations to Congress with respect to those results.&nbsp;