The heating in his flat had been turned up even though it was the middle of summer.
Times, Sunday Times
The leaf colour fades as spring progresses so that by the middle of summer they are a rich, deep green.
Times, Sunday Times
This month's weather has been more like the middle of summer than early spring.
Times, Sunday Times
That could be clear by the middle of summer.
Times, Sunday Times
The centre gets badly snarled up by traffic in the middle of summer.
Times, Sunday Times