Spring is the peak time to visit Chapel Hill. The campus is famous for its dogwoods and azaleas, which bloom from late March through April and transform the grounds into something genuinely beautiful. The weather is mild — warm days, cool evenings — and the town is in full swing before exams draw students indoors.
Fall is the second best season. The trees turn in October, football season is underway at Kenan Stadium, and the academic year brings energy back to the streets after a quieter summer. October and early November hit a sweet spot of good weather and full town activity.
Summer is hot and humid by North Carolina standards, and the university is much quieter with students gone. The Botanical Garden is still worth visiting, and the restaurants stay open, but the town loses some of its character.
The UNC vs. Duke basketball game — the rivalry match of the year — is played once or twice annually between January and March. Getting tickets is nearly impossible unless you know someone, but the atmosphere in town around game time is worth experiencing even if you're watching from a bar.
Halloween on Franklin Street is a Chapel Hill tradition. The street closes to traffic and tens of thousands of people show up in costume for an unofficial street party that has grown into one of the largest Halloween celebrations in the South.