Yes unless the wi-fi hotspot owner makes any charges they're usually free.
O2 never charge for wi-fi use.
It's helpful to turn off the data settings on your phone, and turn off voicemail before you leave the UK.
To support Disasters Emergency Committee: http://www.dec.org.uk/appeals text Nepal to 70000 to send £5
Sky Unlimited Broadband - Windows 10 - Nexus 4 Android 5.1.1
