Predicting the angle of the sun can be a difficult and challenging task. I remember planting tomatoes against the south-facing wall of our house one year. A full sun exposure in April turned into full shade by June because of the roof overhang.
My husband taught me a trick to help me anticipate the sun’s pattern. Go outside at midnight on the night of a full moon, and note where buildings and trees cast their shadows in the moonlight. This is approximately where the sun’s shadows will fall six months later. If you check the full moon’s shadow in December, for example, you will have a good idea of where the shadow of noontime sun will fall in June.