September is Ovarian Cancer Awareness Month, and their colour is teal. OC runs in my family and is what took my mother from us when I was so little, so this month is a big deal in my family as we remember those we've lost and hope/fight for a brighter future.
I do a social media thing every year called "30 Days of Teal" aka "Find the Teal in Every Day" where you post a picture of something teal every day, so some of that tends to bleed over into 365 (though I hope to get other pictures some days too)!
September is also when I paint my nails most-- by far, lol. They're plain finger/toe nails almost all the time, but in September they are often teal!