During Christmas time, I happened to revisit a photo location at sunrise. The scene jogged my memory to photos I took from near the same vantage just a few months earlier. However, the lighting was drastically different. The two greatest differences were the haze and the snow. The first photo was taken amidst thick smoke from nearby wildfires accentuating the haze naturally occurring due to the distance of the hills and mountains. The second photo was taken on a crisp winter day just moments after sunrise.
Despite the former picture being taken about an hour after sunrise and the latter taken a few minutes after sunrise, the greatest difference to note is the angle of the sunlight. The summer photo was taken on July 28. The winter photo was taken on Christmas day. The difference in the sunrise azimuth is 63°. The July sunrise azimuth was 61° and the Christmas sunrise azimuth was 124°. Look at what a difference 63° makes to the lighting. Of course, the lack of haze and clear skies definitely helps the winter sunrise capture. (Another note: the summer shot was taken at 280mm while the winter shot was taken at 400mm.)