In Chengdu,basically November to March is indeed sort of gloomy,and it will probably be rainy and a little chilly.There is a layer of fog-like gray (but not fog) that's nearly perpetually over the sky,but the weather is warm enough for you to wear just a sweater outside.In the summer though,it is definitely not gloomy.It's bright and sunny most days of the week with more visible blue skies than in the larger,more polluted cities,but it's VERY humid and hot.It's known to be a humid region.During the autumn,sometimes it will be gloomy and rainy,and sometimes it will be a fine day with clear autumn sky and crisp air.It's foggy and dry in winter,but not cold.It seldom to have snow there,only one or two times per year.