Avocado fruit softening results from the activity of cell wall degrading enzymes. It is widely known that pre- and postharvest factors affect fruit softening. The large fruit-to-fruit variation at harvest complicates the postharvest control management of batch softening behaviour and thus final quality. The aim of this study was to model Chilean ‘Hass’ avocado softening, destined to local and distant markets, taking into account the biological variation introduced by growing location and harvest seasons. A total of 24 batches were obtained during the season 2018-2019 from different agroecological zones within a valley (coast, intermediate and interior) and two harvest seasons. Fruit softening during either regular air (RA) or controlled atmosphere (CA) storage followed by shelf-life was modelled using a simplified mechanistic model. Most of the model parameters were treated as being generic for all fruit except for one specific parameter, tage, that characterized the fruit at harvest based on its preharvest history, determining the initial fruit firmness and active enzyme at harvest. The model was able to describe 89% of the observed variation of all 24 batches studied. Fruit from agroclimatic zones with higher mean growing temperatures during fruit growing presented a wider range of fruit firmness heterogeneity at harvest. Fruit stored in air at 5°C for 30 d presented a higher synchronization in ripening during the shelf life period as compared to CA batches. The developed model can be utilized to predict the batch specific ripening behaviour of Hass avocado given the distribution of tage.