Do I need a jacket in March on SL?

Extremely specific question here - probably unanswerable but we’ll try! I’m trying to travel with just a carry-on and I’m wondering if I can eliminate a jacket/hoodie? I’m one of those people who’s always cold, so I take a sweatshirt on 90° days because grocery stores and restaurants are always cold. How chilly are the public areas of SL? And outside at night, do you need a jacket? Worse comes to worst, I’ll just weamultiple layers on my flight! Thanks.