data = WeatherData["London", "Temperature", {2014, 10, 10}];
Transpose[{data["Dates"], QuantityMagnitude /@ data["Values"]}] // Normal
gives
{{{2014,10,10,0,20,0.},13.},{{2014,10,10,0,50,0.},13.},{{2014,10,10,1,20,0.},12.},{{2014,10,10,1,50,0.},12.},{{2014,10,10,2,20,0.},12.},{{2014,10,10,2,50,0.},12.},{{2014,10,10,3,20,0.},12.},{{2014,10,10,3,50,0.},12.},{{2014,10,10,4,20,0.},12.},{{2014,10,10,4,50,0.},11.},{{2014,10,10,5,20,0.},11.},{{2014,10,10,5,50,0.},11.},{{2014,10,10,6,20,0.},12.},{{2014,10,10,6,50,0.},12.},{{2014,10,10,7,20,0.},13.},{{2014,10,10,7,50,0.},13.},{{2014,10,10,8,20,0.},14.},{{2014,10,10,8,50,0.},14.},{{2014,10,10,9,20,0.},15.},{{2014,10,10,9,50,0.},16.},{{2014,10,10,10,20,0.},17.},{{2014,10,10,10,50,0.},17.},{{2014,10,10,11,50,0.},16.},{{2014,10,10,12,20,0.},17.},{{2014,10,10,12,50,0.},15.},{{2014,10,10,13,20,0.},16.},{{2014,10,10,13,50,0.},17.},{{2014,10,10,14,20,0.},17.},{{2014,10,10,14,50,0.},17.},{{2014,10,10,15,20,0.},17.},{{2014,10,10,15,50,0.},17.},{{2014,10,10,16,20,0.},17.},{{2014,10,10,16,50,0.},16.},{{2014,10,10,17,20,0.},16.},{{2014,10,10,17,50,0.},15.},{{2014,10,10,18,20,0.},15.},{{2014,10,10,18,50,0.},15.},{{2014,10,10,19,20,0.},15.},{{2014,10,10,19,50,0.},14.},{{2014,10,10,20,20,0.},14.},{{2014,10,10,20,50,0.},14.},{{2014,10,10,21,20,0.},14.},{{2014,10,10,21,50,0.},14.},{{2014,10,10,22,20,0.},13.},{{2014,10,10,22,50,0.},13.},{{2014,10,10,23,20,0.},13.},{{2014,10,10,23,50,0.},13.}}