You may find the following resources useful when planning your drone flight:

NOTAMs: notaminfo.com/ukmap

UAV Forecast: www.uavforecast.com/#/

BBC Weather: www.bbc.co.uk/weather/

CAA: www.caa.co.uk

CAA Documents:

CAA Guidance Document CAP 722: www.publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=415

SkyDemon Flight Planning (clear, custom built vector charts): www.skydemon.aero

SkyDemon Flight Planning Light (free version with limit functionality): www.skydemonlight.com