Public hotspots are generally safe enough for general browsing but we’d advise against using them for anything important like banking. The reason for this is twofold: first, there’s no telling who could be monitoring your activities or what they do with the resulting information.
Second, public networks are rarely well-secured, and as such, are prone to attack. A knowledgeable attacker could spoof a hotspot, steal your personal information (including passwords), and leave within a few minutes and you’d be none the wiser.