The average high temperature for the month of April is 12°C (54°F) which is a big improvement on March, with averages of 6°C (42°F) and an average overnight low of 4°C (38° F).
Temperature will be okay ( around 10-12 degree ) at both the places . However its very breezy/windy in europe so even a 12 degrees will feel like 6 . Atleast that's my experience over 3-4 visits . So carry your warm clothes accordingly
A small tip...Before planning a trip, I always check the weather of the destination online on accuweather.com... it gives a day wise, month wise and even hourly forecast...hv found it pretty accurate and reliable over the years.