All international flights connect to Delhi International airport. From Delhi, a domestic flight will connect you to Chandigarh.
The weather in India varies greatly by region,but generally the best time to visit is during the cool,dry season,which runs from November to March.
The Hola Mohalla ride is held in march,which is an excellent time to visit Punjab, the weather is lovely. Temperatures vary between 24° C to 34° C and make for good riding.