Most writers would agree that weather is an integral piece of setting the scene. So much so, that in films or television, you may even become blind to the setup due to the expectation of weather. Quick-- what are the conditions in the climactic scene of Titanic? The opening sequence in LOST? Takes a minute or two to remember, doesn’t it? But once you recall the weather, I’ll bet you envisioned the rest of the scene down to minor details. Now I’ll direct your thoughts to how these decisions operate on a subconscious level.
Sun: Along with providing brightness to the landscape, this otherwise bland forecast can offer your reader with optimistic feelings and visceral connections to their own fair-weather memories.