Dairy calves are susceptible to heat stress when environmental temperatures exceed 68°F. Heat stress conditions cause decreases in feed intake and calf health. The objective of this study was to compare the behavior and well-being of Holstein heifer calves housed in 2 different housing systems during hot weather. This study was conducted over the course of 2 summers (Trial 1 and Trial 2). At the age of 24 - 48 h, calves were assigned to one of 2 treatments: 1) housed in stalls in a barn (S; n = 14) or 2) housed in hutches placed outside (H; n = 8). Each calf was observed until weaning at 42 d of age. Temperature and relative humidity within the housing systems were recorded at 1-h intervals using data loggers (HOBO) and used to calculate the temperature humidity index (THI). Calf body temperatures were measured hourly using temperature recording devices (iButton). Calf BW were measured weekly and ADG was calculated. Blood samples were collected at 7, 24, and 42 d of age via jugular venipuncture and analyzed for thyroxine concentrations using enzyme-linked immunosorbent assays. Data were analyzed using Pearson correlations and mixed model ANOVAs with repeated measures. No differences between trials were detected so data were combined. The THI was significantly lower in hutches (63.79 ± 0.20) than in stalls (66.44 ± 0.16; P < 0.0001). Calves housed in hutches had higher body temperatures (S: 38.59 ± 0.008°C; H: 38.92 ± 0.01°C; P < 0.0001), ADG (S: 0.6 ± 0.04 kg/d; H: 1.1 ± 0.06 kg/d; P < 0.0001), and tended to have higher plasma thyroxine concentrations (S: 15.83 µg/dL; H: 16.37 ± 0.22 µg/dL; P = 0.08) than calves housed in stalls. Although the THI was lower in hutches than in stalls, calves housed in hutches had higher body temperatures, but these effects did not negatively impact calf growth. Future studies may investigate how calf behavior is affected by hot weather in these housing systems.