In the centre of Barcelona you will find most shops and restaurants open. However there will still be plenty of tourists. Barcelona has decent enough beaches but the locals will really appreciate it if visitors do not consider it a beach resort and don’t wear beachwear when visiting churches, restaurants, etc.
Barcelona is great off-season and is a lovely city even in winter months of January and February as long as the possibility of rain is low. During these months the city is not too cold averaging between 9-10°C with sunny and blue skies.
Given the high humidity, 19-23°C is considered comfortable weather, which is normally the temperature between April and June and between late September to November; this is the best time to visit the city – anything warmer can feel too hot.
Easter week, as well as Christmas to New Year’s Eve, are very busy times. If you’d rather avoid the crowds, don’t come during those dates. Also, avoid visiting during the Mobile World Congress or the Formula 1 racing, unless you are ready to pay extremely expensive hotel rates.