For the Final Run, the V07 record ends in September 2025 because the parent products feeding into the IMERG algorithm (CORRA and GPROF) are being upgraded to V08. If processing were to go beyond September, the Final record would have to use V08 inputs instead of V07 inputs. Since the IMERG V07 code is configured with the expectation of V07 inputs, this would introduce potential discontinuities in the Final record. The IMERG V08 Final Run is planned for release in the summer of 2026, though this timeline assumes that V08 of the parent products behaves within expected bounds. When this release is computed, it will be a retrospective processing of the full record, starting from January 1998 to the present day with the usual 4-month latency.

For the Late and Early Runs, the V07 production will continue as the parent products are being upgraded to V08. Already, IMERG V07 Late and Early are operating in “hybrid” mode, using the IMERG V07 algorithm but ingesting GPROF V08. As such, there may be discontinuities in the record. To mitigate these discontinuities, the dynamic calibration of the GPROF passive microwave precipitation estimates to the CORRA reference has been modified.  Starting March 1, the CORRA calibration has been set to climatological values that are periodically updated to reflect seasonal conditions. That is, the calibration of GPROF V08 to CORRA V07 is being computed from selected seasonal periods in previous years, then used for the same time period in 2026. The Late and Early Runs will be in this “hybrid V07” posture until the near-real-time processing system is ready to switch to V08, which is expected to take place no sooner than fall of 2026. Our plan is to provide users with a retrospective record (i.e., beginning 1998) of IMERG V08 Late and Early Runs prior to this switch but after the release of IMERG V08 Final Run. The set of diagrams below summarizes the different steps in the transition of the Late and Early Runs.