China in summer suggestions
 

Hello, my husband, teen son and I are visiting China for the first time starting on the 4th week of June for 2-3 weeks. This trip will proceed a 3 week trip in Japan. We are thinking to start in Hong Kong and then travel north, Chongqing, Chengdu and then Beijing, but are open to suggestions on how to best enjoy China at that time for the year. This is part of a bigger Asia trip. After China we will go to Singapore for a couple of nights, then look for an easy a relaxing place to spend a few nights before we visit family in India at the end of July (maybe Lombok or Langkawi). Do you have suggestions on a tour agency to help us plan the China segment?

No need to work with a tour agency unless you want to -- it's perfectly easy to plan a trip to China independently. You'll need a good guidebook or two. For excellent climate data, consult weatherspark.com. And you might take a look at my old trip report, if for no other reason than to see that traveling independently in China can be quite unexpectedly delightful.
https://www.fodors.com/community/asi...mazing-844129/

If you haven't already seen it, japan-guide.com is a truly excellent resource for travelers to Japan.

Singapore will be hot hot HOT and humid. A couple of nights might suit your interests; I wanted much more time there. This trip report covers time in Singapore and in Bali; you might find some useful information: https://www.fodors.com/community/asi...-bali-1116191/

In order to escape the summer humidity, we arranged for an 8 night trip to the northwest of China, flying into Lanzhou and taking a route to Bingling Si, Xiahe, Labrang Monastery Langmusi, Jiuzhaigou, Huanglong, and Songpan. Nothing but clear skies and mild temps. We had a private car, driver, and guide. We were in an intensely rural part of China with vast stretches of mountains, grasslands, and Tibetan tents. However there were always some other tourists, internet cafes, and the like. It was the trip of a lifetime.

China in summer suggestions
 

That sounds like an incredible multi-country journey for your family! Since you are starting in late June, just be prepared for high humidity and heat in cities like Chongqing and Chengdu.

Moving from Hong Kong up through Chongqing and Chengdu before hitting Beijing is a logical route. For your relaxing finish, Langkawi is often easier to reach from Singapore and has a very laid-back vibe that would contrast well with the busy cities of China.

Regarding a tour agency, many travelers find that booking high-speed rail and internal flights is quite manageable on your own if you prefer flexibility, but having a local guide in Beijing or Chengdu can help navigate the crowds during the summer peak.