If you want to avoid the high travel season, then steer clear of the summer months between June and August, and the holidays. Though the University of California, Berkeley, and its neighboring businesses tend to get a little quieter around these times, the freeways are still pretty congested, which can prove extra frustrating when the 80 is already ill-equipped to handle routine traffic.
September and October are shoulder season for leisure travel but peak season for business travel. While this doesn’t have a huge impact on Berkeley, as most of the business travelers will be headed into San Francisco for the many conventions held there this time of year, you should still anticipate more foot traffic around the area’s transit stations.
January through April is the low season, with January and February usually seeing the deepest dip in travelers.
One of the great things about Berkeley, and more generally East Bay, is that the weather is much better than in frequently overcast and chilly San Francisco. Outside of the annual June gloom and rainy spring, Berkeley is sunny, with clear skies many days of the year. Summers enjoy averages in the high 60s and low 70s, while winters dip into the 50s. Many agree that September and October offer the best weather.