Since the ACT test is the most important test of a student's academic career, everyone wants to know what is the best month to take the test. The short answer is that the best month to register to take the ACT test is in December, on a national test date. There are two reasons.
First, taking the ACT test in December gives you plenty of time to look at your score and determine what areas you need to study more and then get better prepared for a retake in the Spring.
The December ACT test date gives you some great study time over the Thanksgiving break to prepare. It also gives you the Christmas break, by which time you should have your score report, to make a plan and start studying for the Spring.
Second, when you take the ACT test in December on a national test date (that is, it's not just your school administering the test alone), you are able to pay an additional $19 and get a Test Information Release (TIR).
This report will give you the questions and answers from your test so that you will know exactly which questions you got wrong. This is worth its weight in gold! It will be your roadmap for exactly what type of questions you need to study and learn more about to increase your score!
There is nothing magical about getting a high ACT score, but just working hard is not enough. You must work smart. Register to take the test in December and you will be positioned to get your highest possible ACT score when you retake the test in the Spring.