Your temps look good. If you want more top end cooling you can mod the fan a little by relocating the thermistor to the space between the fins instead of on the outside. I went for that option rather than clipping the thermistor and hardwiring the fan to full speed. It's still quiet and I get more RPM's at lower temps. It stays at 37C - 39C but will climb to 42C under heavy gaming. I can live with that.
Relocating the sensor is easy. Remove the fan and take a very small screwdriver or other sharp object and separate the thermistor leads from the power leads. Then, push the thermistor down between the fins and apply a small dab of glue to the leads near the fan motor to keep it from hanging by the leads alone. You'll see once you get it apart.
I will add this: I've got some pretty good ventilation so my results may be better than others. Not bragging, just a fact that I discovered after spending another $100 for a new PS with dual fans. Really sucks the heat away from the HS. Temp difference between the case temp and HS temp is usually no more than 5C.
Either way, it sounds like you are in good shape. Nothing to worry about unless you just want more cooling.
Good luck.