Australia just had their busiest flu season in five years, but how does Australia predict what will happen in the U.S.?

It’s still early for the flu, but doctors are preparing for a rough season and they’re looking at Australia. The Southern Hemisphere is transitioning out of winter after it was hit hard with sickness.

Dr. Devin Minior, from Banner Health, said the strains of flu in the Southern Hemisphere can often parallel what happens in our own hemisphere.

“It’s a good indicator. It’s not absolutely guaranteed that we’re going to be having the same type of flu season but it gives us a good estimate a good general understanding of the type of flu strains that are out that people are getting sick with.”

Minior said flu season usually starts in November and December but this year it might come as early as October.