"in summer" is also correct. "We do not go to school in summer" should be accepted. Reported on Nov. 19, 2017.
"we don't go to school in summer" is what I had also. Agree it should be accepted
during the summer, we do not attend school should be accepted (jan 4th 2018)
Why is 夏 by itself summer but we still have to write 夏天 ?
I suppose is to avoid misunderstandings with many other homophones in Chinese. There are a lot of examples like this: 干燥，衣服，付款，计算，洗澡 ecc.
Last question ”这里在冬天下雪吗“ uses 在 before the season. Can this be omitted as is the case for this question?
The, is not needed in this sentence and is awkward when used.
Why is it not 在夏？ would that mean the same thing?