The stable fly Stomoxys calcitrans (L.) (Diptera: Muscidae) has been a severe biting pest in North America for the last 250 years. Severe seasonal infestation is a common occurrence on Canadian livestock production sites. The projected effects of climate warming within the next 30 years may lead to even larger infestations of longer duration, increasing both economic losses and concerns regarding animal welfare. To understand the relationship between stable fly population dynamics and the environmental factors that drive population fluctuations, stable fly activity was monitored at three dairy operations near Glenlea, Manitoba for two years (June to October 2017 and May to October 2018). Adult stable flies were trapped using Coroplast® panels for 24-hours once weekly and changes in adult abundance, sex ratios, and age structure were examined. During both years, adult abundance followed a unimodal trend with the highest abundance recorded in July. Pupal stable flies were collected in autumn (November 2017 and September 2018) to determine the potential for overwintering survival under laboratory and field conditions. In the lab, pupae were held at 0°C, 2°C, or 5°C and sampled every two weeks from 24 November 2017 to 8 June 2018, and 26 September 2018 to 22 May 2019 to examine adult emergence, pupal development, and parasitism. Two adults emerged from the 1350 pupae observed in 2017 and 256 adults emerged from the 1440 pupae observed in 2018. There were 166 pupal parasitoids recovered in 2017 and 17 pupal parasitoids recovered in 2018. Significantly more adult flies emerged when held at 5°C, and intrapuparial development was observed under 10°C. As evidenced by the results of this study, large numbers of adult stable flies are unlikely to overwinter unsheltered in Manitoba, but pupal parasitoids are able to. Stable fly population dynamics and overwintering survival of stable flies and pupal parasitoids have important implications for producers looking to reduce economic loss and animal welfare concerns, while also preventing environmental impacts from overusing chemical controls.