1. The temperature here is of medium.

Question

2. The temperature here is of average.
3. The temperature here is neither low now high.

(Would you correct errors?)

Answer 1

3. is probably best. But we don't know what the lows and highs are.

1 and 2 are wrong. The word "of" shouldn't be there. Also -- we have no frame of reference to what is "medium" or "average."

We might say: "We have moderate temperatures here."

But without a reference point -- that isn't very clear. To me, moderate temperatures are in the 60s and 70s Fahrenheit. But to many people in the world, those are either cold or hot temperatures.

Answer 2

3. small typing error:
The temperature here is neither low nor high.