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Freshwater turtles are one of the most threatened vertebrate groups. Climate change is a major threat to these species, with impacts affecting all life‐history stages. There is currently a limited understanding of how changes in climate may alter the environmental triggers for hatching and emergence from the nests of freshwater turtle hatchlings. This precludes making predictions about how climate change may impact freshwater turtle recruitment success. The southwestern snake‐necked turtle (Chelodina oblonga) is endemic to south‐western Australia, a global biodiversity hotspot that has undergone severe climatic drying. Recruitment failure is thought to be occurring in many populations of the species. However, there is little understanding as to how environmental change may be influencing recruitment. This study aimed to: (1) determine the incubation duration and hatching and hatchling emergence success of C. oblonga, (2) determine if the species exhibits hatching or emergence synchrony and/or delayed emergence and (3) quantify the effects of temperature and rainfall on hatchling emergence. Using this information, the study assesses how climatic drying and warming may be impacting C. oblonga's early life‐history. Between 2018 and 2020 nest sites were monitored around a large urban wetland with weekly assessments of egg and hatchling status. Incubation duration and hatching and hatchling emergence success were calculated, and generalized linear models were built to determine how temperature and/or rainfall predicted emergence. Hatchlings either emerged shortly after hatching or overwintered in the nest, and both hatching and emergence were asynchronous. Both emergence periods were positively associated with temperature and rainfall. This study reveals that incubation duration, hatching success, hatchling emergence and survival are all likely to be impacted by recent and projected climate change, and especially drying. Warming and drying are predicted for many temperate regions globally, and it is therefore important that their impacts on the early life history of freshwater turtles be better understood. [ABSTRACT FROM AUTHOR]

1. We investigated the influence of duration of inundation-induced diapause, incubation temperature and clutch of origin on incubation duration and survivorship of eggs of the Snake-Necked Turtle, Chelodina rugosa, from the wet–dry tropics of northern Australia. 2. Eggs of C. rugosa survive at least 25 weeks’ inundation, almost 6 months, with a clear optimal inundation duration of 6 weeks. Eggs not held under water suffered the same mortality as eggs inundated for 25 weeks. Underwater nesting is not a facultative capacity but, rather, inundation is essential for optimal survivorship of embryos. 3. Inundation duration had a profound effect on incubation period, reducing it by up to 9 weeks over what would be expected for a given temperature. Eggs inundated for up to 7 weeks complete incubation faster than had they been laid at the same time in dry ground. 4. There was remarkable variability in incubation period remaining after correcting for the effect of incubation temperature, inundation duration and clutch. 5. We interpret these traits as adaptations that match the timing and duration of the period available for nesting to the timing and duration of the period available for successful hatching, emergence from the nest and hatchling survival. Our interpretation is placed in the context of considerable environmental stochasticity in the factors driving these variables. [ABSTRACT FROM AUTHOR]