Along with pumpkin spice everything, crisp outdoors runs, and anything-but-basic sweaters-and-leggings combos, fall also spells flu season. Early findings have indicated that 2018’s vaccine is about 17 percent effective in combatting the flu. But apart from giving you a greater chance of avoiding the illness yourself, the National Institute of Allergy and Infectious Diseases notes that, when as many people as possible get the shot, entire communities become less at risk for an outbreak.

According to one doctor, there’s also an ideal date range to mark “flu vac” on your Google Cal.  “When it comes to timing for your flu shot, you have to balance getting it early enough to have protection before the flu arrives (as early as October), while also wanting that protection to last through the season (as late as May),” says Darria Long Gillespie, MD, an ER doctor and author of Mom Hacks. 

The expert explains that the season really peaks in December through February, so she likes to “play the odds” and get vaccinated some time between late September and the second week of October. She also notes that the CDC recommends the tail-end of October at the very, very latest.

The expert explains that the season really peaks in December through February, so she likes to “play the odds” and get vaccinated some time between late September and the second week of October.

Just to be on the safe side though—try to get yours before Halloween. “Beware waiting too long—offices can run out of the vaccine, so make sure you have an appointment and are proactive this season, so you don’t get caught off guard by shortages,” advises Dr. Gillespie. No need for a spooky case of chills, fever, and sore throat ruining your GNI movie marathon.

Wondering how your state stacks up health coverage-wise—here’s your answer. And if you’re not quite sure if you’ve caught a cold, or just have allergies, these eight signals will clue you in.