Analysing shifts in the warmest day of the year in Tanzania (1981–2023): Implications for climate adaptation

This study investigates temporal and spatial shifts on a single warmest day per year across Tanzania from 1981 to 2023, utilising ERA5 reanalysis data and advanced spatial analytics. The findings reveal significant changes in the timing and intensity of temperature peaks. Notably, northern regions influenced by Lake Victoria experience their warmest days later in the year (August–September), while coastal and central regions encounter earlier peaks (January–March). Quantitative analysis shows an average shift of 17 days later on the warmest day for 1.5% of the study area, primarily in western highlands. In comparison, coastal and central areas report a shift up to 65 days earlier. Spatial analyses, including Emerging Hot Spot and Local Outlier Analysis, identified warming trends in 0.6% of southern Tanzania, indicating persistent delays in peak temperatures. Conversely, 24.9% of the study area exhibits oscillating temperature patterns, reflecting increased climate variability. Regions with significant trends were statistically validated using the Mann-Kendall test (p < 0.05), revealing critical temporal patterns. These findings underscore the need for tailored adaptation strategies. Delayed warming in western highlands requires adjusted agricultural calendars, while earlier warming in coastal and central areas necessitates water management reforms. The study bridges critical research gaps on temperature extremes in Tanzania, providing actionable insights for agriculture, water management, and public health planning. This framework offers a model for addressing similar challenges in other regions undergoing climate variability.