Mungbean is predominantly cultivated within a subtropical climate, and its potential for cultivation in temperate regions as a summer crop has not been comprehensively assessed. This research investigates the influence of temperature and seasonal variation with sowing time on mungbean phenology, growth and yield at five locations within the temperate environment of southeastern Australia (Victoria). Five mungbean varieties (Jade-AU, Celera II-AU, Golden Dragon, Putland and Crystal) were evaluated across two times of sowing (TOS) (spring and early summer) over 2 years (2020-2021 and 2021-2022 summers) at sites in southwestern (Hamilton and Horsham), northeastern (Rutherglen) and northwestern (Ouyen and Woomelang) Victoria. These locations are characterised by winter-dominant rainfall patterns with sporadic summer rainfall events, which can be significant. Annual rainfall varied across sites: low rainfall (< 350 mm, Ouyen and Woomelang), medium rainfall (350-450 mm, Horsham) and high rainfall (> 350 mm, Hamilton and Rutherglen). Early sowing coincided with lower soil temperatures, leading to delayed emergence and reduced establishment. However, TOS did not significantly influence grain yield, except at Rutherglen (TOS 1, 715 kg/ha; TOS 2, 1576 kg/ha). Grain yield was correlated with grain number and biomass, significantly contributing to variations in yield. The variety Jade-AU exhibited superior performance in low and medium rainfall regions in Victoria, whereas Putland and Crystal varieties demonstrated optimal performance in high rainfall zones. Under dryland cropping conditions, northeastern Victoria (e.g., Rutherglen) may represent the most promising opportunity for mungbean cultivation. Nevertheless, when selecting varieties for summer mungbean cultivation in southern Australia, it is imperative to consider differences in days to first flowering, yield potential, heat stress tolerance and rainfall patterns.