I am traveling in eastern China (Bejing/Chengdu/Guilin/Shanghai) this coming July and I know it will be hot, but can someone give me first-hand experiences of just how hot it may be? I am imagining New Delhi-like heat and humidity in Guilin and Shanghai, but what about Chengdu and Beijing?

I can only speak for Shanghai. July is normally very hot (high in the 90's) and very muggy. Nights are only 10 degrees or so cooler. July is also in the monsoon season.
By the way, Chengdu and Guilin are not in eastern China, but in southwest China.

Take an umbrella to guard yourself from the sun as the local women do. A wet kerchief around your neck helps. Always keep plenty of water handy.

The heat and humidity are oppressive and debilitating. Hard-to-breathe hot. Ninety-seven-degrees-Fahrenheit-at-11-pm hot.

Bejing is slightly better than Shanghai dry instead of muggy, Guilin is slightly better than Beijing but warm enough. Not a pleasant season to travel.

www.weatherbase.com

Shanghai may be muggier, but Beijing has its fair share of humidity. It's a town that's dry as a bone in the winter and hot and humid in the summer. We're leaving China this May and I am so happy we won't suffer through another Beijing summer!

I will also be traveling in China this July and am expecting uncomfortably hot and humid weather. Are there certain areas of China that will be cooler?

So far, I'm planning to be in Beijing, Xi'an and the Guilin/Yangshuo area and will be adding another destination. I've heard Lijiang may be a little cooler as it's in the mountains. Any other "cooler" suggestions would be appreciated.

Chengdu is in the Sichuan Basin, and is also hot in summer too. Average high in July is 85F, but more importantly, it gets 9.1in of rain in July. So, expect extremely high humidity.

Kunming will be in the 70's (at 6,000 feet), often overcast, humidity is tolerable compared to the other cities. Chengdu does get humid.

Do not forget insect repellent. We were consumed by mosquitos when we landed at the airport in Guilin in late May!

it is about 33 degrees in Guilin Yangshuo area.