Unless the first law of thermodynamics has been repealed (conservation of energy), even if there may be some localized increase in temperature where the wind turbines are, there would have to be some equivalent amount of cooling downstream.
If anything the net effect should be some very slight cooling, since some of the kinetic energy of the wind is transformed into electric energy by the wind turbines. Eventually though even the electric energy generated by the wind will be reconverted to heat as the electricity generated runs fridges and ovens and laptops and...
Bottom line there should be no global temperature effect by the operation of wind turbines.
So if you think about it, under normal conditions the atmosphere probably cools more rapidly than the land underneath it - radiative cooling off into space. So a wind blowing across the land would be cooler than the ground, and thus extract heat from the ground.
Now we have huge turbine farms. They are extracting kinetic energy, slowing the airflow down. This means less air mass per unit time blowing over the ground, less energy transfer. The ground retains more of its daytime heat.
Well, that's a working theory anyway. Could probably be tested fairly easily with anemometers and thermometers.