<p>Climate change and sea level rise may increase pressure on Belém’s drainage network, which is already affected by the tides that invade the city. Due to insufficient data and the interference of river flows bordering the study area, current methods are limited in analysing the complexity of the climate variables involved in tidal simulation. Thus, to fill this gap, this study proposes a mathematical model based on Bayesian inference techniques to provide hourly forecasts of current and future tidal heights associated with mean sea level projection data from climate scenarios (SSP2-4.5 and SSP5-8.5). Statistical performance indicated that MCMC has good predictive capacity, considering a 95% reliability in tidal height simulations, returning KGE and NSE values above 0.9 and RMSE values below 0.035 m in both calibration and validation. The MCMC model proposed in this study accurately reproduced the tidal amplitude and phase, both spring and neap tides, despite the influence of river flow, has proven to be suitable in scenarios where measurements are scarce or have high variability. The set of maximum tidal values associated with sea level rises above 4 m were more frequent in the simulations 2050 onward for the SSP2-4.5 and SSP5-8.5 climate scenarios, demonstrating that coastal flooding rates will be significantly higher if adaptation measures to mitigate the effects in the most vulnerable areas are not implemented in the near future.</p> Graphical Abstract <p>This graphical summary visually demonstrates the impact of tidal height associated with sea level rise on climate change scenarios in Belém, in the Brazilian Amazon. It illustrates tidal heights considering NASA projections (sea level projection tool) for future climate scenarios (2020–2099). A framework based on Bayesian inference techniques is used, combining the Markov Chain Monte Carlo (MCMC) method with the Metropolis-Hastings (MH) algorithm to provide hourly forecasts of current and future tidal heights. This contribution aims to explore the challenges associated with predictive capability for tidal heights, where the consistent presence of rising water levels and increased precipitation are prevalent. The results obtained for the SSP2-4.5 and SSP5-8.5 scenarios simulated with MCMC are consistent with the observed data used as inputs to reduce model uncertainty. The main changes in maximum tide as a function of sea level rise are highlighted. These tidal forecasts are essential for flood prediction and provide data for formulating strategies to mitigate the effects of climate change in the region. This is necessary for implementing realistic policies based on tidal projections in the Amazon, especially in topographically more vulnerable areas. Improved visualizations, including integrated techniques and historical data, clarify complex tidal forecasts, alerting us specifically to the consequences of sea level rise and increased tides, essential for policymakers and researchers.</p>