What are the best months to visit Myrtle Beach?
High season starts in mid-May and goes through mid-August. This is when it is most crowded, premium rates for hotels and condos, crowds etc... However, everything is open and funtioning, fully staffed etc... The heat and humidity are at the highest from mid-June until September. Depending on what you're looking for, may would think this is the "best" time to visit. Living not too far, I can say that this would be the least desirable for me. Later and September and October are perfect for still enjoying the beach, warm days, amazing sunrises and sunsets and no crowds. The best part is the cost of lodging drops significantly after the kids go back to school. Earlier in the season - April / May, leans towards Spring Break and prices tend to be higher and crowds are starting to return. Anytime "off-season" is best but again, this is my opinion and may not be what you're looking for.
That depends primarily upon what you want to do while you're here. If swimming in the ocean is a priority, June and July is probably the best time. It is also the busiest time. If you prefer cooler weather and strolls on the beach suit you better than swimming, October and November would be my pick. Still busy, but not as bad as summer. With only a few exceptions, MB has become a 12-month destination, although January and February usually have some short periods of unpleasant weather. There's always something to do; you just have to pick something that's appropriate for the weather.
My favorite month is Sept, the weather and water are warm and it is far less crowded. I also enjoy May & Oct.
I would have to agree with Len K that after Labor Day is the perfect time to go and for the same reasons. Ocean temperatures will still be around 80 for most of September. Most places don't start cutting hours or shutting down until November so there will still be plenty to keep you occupied as well.
Thank you all for your answers. All helpful.