verb tense after when

Question

1. I feel more positive when the sun is shining.
2. I feel more positive when the sun shines.

Which of the above sentences is correct? If both, Are there any differences in the meaning of?

Answer 1

They would both be taken to mean the same thing, though “is shining” would be more natural and idiomatic; “shines” feels a little more poetic to me.

“Is shining” refers more to the state of the sun, whereas “shines” refers more to something the sun is doing - perhaps you might picture the sun beginning to shine after it hadn’t been shining with “shines”, whereas “is shining” refers purely to the state.