<p>I've heard many different answers on how important grades are your senior year and it would be nice to know.</p>
<p>In most cases, yes. But it’s not that they check. Rather, you will have your school send them your first-semester grades.</p>
<p>Some schools don’t request mid-year grades. I was kind of surprised when my state flagship didn’t. But very many do. Your school will send an updated transcript along with your mid-year report. (See the Common Application.) The purpose of the mid-year report is to verify that you are still enrolled in the classes you told colleges you would be taking–or to update them if there have been changes–and to report your grades from the first semester of senior year. Very little besides that.</p>
<p>If you have applied Early Action or Early Decision, colleges will have to make their decisions before mid-year grades are available, so in the case of EA or ED, colleges will not base their admissions decisions on your senior-fall grades. But for regular decision, most colleges and universities will be given those grades by your high school, and most will weigh them heavily. After all, if you’re a senior, the classes you’re taking now probably come closer to approximating college classes than anything else you’ve taken in high school.</p>
<p>Most colleges that release regular admission decisions in March to early April require you to provide mid-year grades after you have applied and those are used to determine admission along with other grades. Most colleges (which includes the majority of public universities) that send out regular admission decisions in Feb or before use grades through junior year to determine admission.</p>
<p>All colleges, after you are admitted, reserve the right to withdraw your admission once they get your final senior year grades.</p>
<p>Note that if you apply to a college that requires the mid-year grades for the admission decison, you should not assume your high school will automatically send them and you should make sure that you request your high school do so.</p>
<p>Senior first semester grade may help RD application. If your test scores and/or GPA are not at the admission average yet, I would suggest not to apply EA/ED by apply ED after improving them in the first semester for a better chance. Even for students accepted in EA/ED, you still need to submit senior transcript. If your grades go below their expectation, you may be rescinded.</p>