Running the Bank of America Chicago Marathon on Sunday? Cheering someone on?
Better bundle up.
As the hours tick closer to the 35th annual race, weather radars point to the same fate for 45,000 runners: Baby, it's gonna be cold outside.
NBC Chicago meteorologist Andy Avalos predicts highs in the upper 30s and light winds at the start of Sunday's marathon. Temps could range from 37 degrees at 7:30 a.m. to 40 degrees at 10 a.m. and 44 at noon.
How can runners and spectators stay warm?
Cindy Hamilton of Nike suggests starting with a good base layer to keep you dry and comfortable and build from there.
"That means looking for a dry-fit fabric that's going to wick away the sweat," Hamilton told NBC Chicago, "and then from there you want to layer up. So add a jacket, add a hat, add gloves."
Rain should stay away for the marathon, and the rest of the day is expected to be partly sunny, breezy and still chilly in the afternoon with highs only in the low to mid 50s.
Conditions won't be much warmer leading up to the marathon either. On Friday, highs in the mid- to low-50s are expected with rain and showers in far southern sections and northwest Indiana. A few more scattered showers could be possible to the south and east of Chicago later in the day.
The unseasonable chill continues Saturday with highs in the upper 40s and lower 50s.