Holstein calves (n = 39; initial body weight [BW] = 37.6 ± 5.2 kg) were used to evaluate the effects of 3 milk replacers (MR) feeding programs on performance and metabolism during summer. Calves were randomly assigned to 3 treatments including: control (CON, 0.57 kg/d of a 20% CP and 20% fat MR), intermediate (IL, 0.68 kg/d of a 26% CP and 17% fat MR [26:17]), or high (HL, 0.79 kg/d of 26:17), at 3 d of age (DOA). Calves were managed similarly and housed in polyethylene hutches on sand. Milk replacer (12% solids) was offered twice daily until 42 DOA when MR was fed once a day to reduce its intake by 50%. Calves were weaned at 49 DOA and remained in hutches until 56 DOA. Calf starter and water were offered ad libitum. Ambient temperature and relative humidity in and outside hutches were assessed hourly to calculate temperature-humidity index. Starter and MR intakes were recorded twice daily. Respiration rate and rectal temperature were determined thrice weekly. Body weight was measured at 3 DOA and at 2, 4, 6, 7, and 8 wk of age. Plasma was collected at 2, 5, 10, 14, 28, 42, 43, 45, 47, 49, 51, and 56 DOA to analyze glucose, β-hydroxybutyrate, triglycerides, and nonesterified fatty acids. Data were analyzed using the mixed procedure of SAS. During the trial, temperature-humidity index averaged 75 in and outside the hutches. There was no treatment effect on starter intake, rectal temperature or respiration rate (P > 0.57). By 7 DOA, calves fed IL and HL diets consumed the same amount of MR but higher than CON, but on wk 2 calves from all treatments had similar MR consumption before returning to the projected intake by design (treatment × time, P < 0.01). The IL and HL calves had similar BW but were heavier than CON on wk 6, 7, and 8 (treatment × time, P < 0.01). Calves fed IL and HL diets had similar average daily gain which was higher than CON (P < 0.05). There was no difference among treatments in plasma metabolites (P > 0.38). In summary, feeding an intermediate level of MR during summer improved calf growth than control diet, but a higher MR allowance did not support further improvements in calf performance.