Drive Temps

Hello all, new to this forum. I just purchased 4 HGST 6TB NAS drives for my server, and as i’m testing them to insure they will hold up, I noticed that compared to my WD reds, the HGST drives all operate at 12 degrees warmer than the WD’s… That makes for a temperature of 45 degrees, in some cases 48 depending on what i’m doing. Is this normal?