Complex sentence: August is the hottest month and the average temperature is about 25 ℃; the average temperature of January, the coldest month, is -0.7 ℃; and the average temperature of the year is 12.7 ℃.
Split into simpler sentences: August is the hottest month and the average temperature is about 25 ℃. The average temperature in January, the coldest month, is -0.7 ℃ and the average temperature of the year is 12.7 ℃.