Our objective was to clarify the reproductive characteristics of English Berkshire female pigs in a humid subtropical zone. We examined interactions between 2 breeds (English Berkshire and crossbred females) and climatic factors for reproductive performance. We analyzed 63,227 first-service records of 11,992 females in 12 herds. Climate data were obtained from 4 weather stations located close to the studied herds. Mean daily maximum temperatures (Tmax) and daily average relative humidity (ARH) for different periods around servicing and farrowing of each female were coordinated with that female’s reproductive performance data. Multilevel mixed-effects models were applied to the data. There were 2-way interactions between the breed and either Tmax or ARH for weaning-to-first-mating interval (WMI), total born and farrowing rate (P < 0.05). The WMI in Berkshire sows increased by 0.10 (SE: 0.008) days as Tmax increased by each degree Celsius (P < 0.05), whereas in crossbred sows it only increased by 0.01 (0.005) days (P < 0.05). The WMI in crossbred sows also increased by 0.03 (0.007) days as ARH increased by one percent (P < 0.05). However, there was no such association in Berkshire sows (P = 0.37). In Berkshire females total born decreased by 0.02 (0.003) pigs for each degree Celsius increase in Tmax (P < 0.05), whereas that in crossbred females decreased by 0.03 (0.002) pigs (P < 0.05). With regard to farrowing rates, the odds ratios in Berkshire and crossbred females were 0.973 (95% confidence intervals: 0.967–0.979) and 0.986 (0.981–0.991) for Tmax, respectively. Therefore, we recommend producers applying advanced cooling systems for Berkshire females as well as crossbred females.