The junior high section in the United States typically starts school between the end of August and the beginning of September. This timing aligns with the traditional academic calendar, which has been in place for many years. According to the National Center for Education Statistics (NCES), the majority of public schools across the country begin the school year in early September, with a significant number starting between the 1st and 10th of the month. This early start allows for a full academic year, which typically spans from early September to late May or early June.

The reasons for this timing are multifaceted. Firstly, the early start of the school year is influenced by the calendar year and the need to complete a full academic year. This ensures that students have enough time to cover the curriculum and prepare for standardized tests. Secondly, the early start also allows for a more structured and consistent learning environment, as students and teachers can establish routines and expectations from the beginning of the year. Additionally, the early start can help mitigate the effects of summer learning loss, which is a well-documented phenomenon where students lose some of the knowledge and skills they gained during the previous school year.

Data from the NCES reveals that in the 2019-2020 school year, approximately 48% of public schools in the United States started the school year in September, with the majority of these schools beginning between the 1st and 10th of the month. This trend has been consistent over the years, with only a small percentage of schools starting their academic year in August or later.

The early start of the junior high section is also influenced by local and regional factors. For example, some districts may have specific start dates based on local holidays or community needs. However, the overall trend remains consistent, with the majority of junior high schools following the traditional academic calendar.

In conclusion, the junior high section in the United States typically starts school between the end of August and the beginning of September, aligning with the traditional academic calendar. This timing is influenced by the need to complete a full academic year, establish a structured learning environment, and mitigate summer learning loss. Data from the NCES supports this trend, with the majority of public schools starting their academic year in early September.