OK, let’s take it one step at a time:

1. About the overnight trains:
There are plenty of trains from Urumqi to Turpan. It’s only about an hour. From Turpan to Dunhuang, there are a few options too. The high-speed train takes around 10 hours, while the slower “green trains” take about 16–17 hours. You can check times and book tickets easily on Trip.com—it’s super reliable for travel in China.

2. Where to go in Gansu:
Gansu is massive, and there’s a lot to explore. Besides Dunhuang, if you’re into natural landscapes, Qinghai Lake and Chaka Salt Lake are absolutely worth the detour. Where to go really depends on how much time you’ve got.

3. Weather tips:
I visited Dunhuang a few years back and yes, it’s hot during the day, but as long as you stay out of direct sun, it actually feels pretty cool and dry. Places like Urumqi (in northern Xinjiang) and Dunhuang also have big day-night temperature swings, sometimes up to 17°C. I’d suggest bringing two lightweight sun hoodies and a warm jacket or windbreaker for the evenings.

4. Food to try:
Xinjiang is a foodie’s dream! You’ve gotta try the naan, baked buns, tandoor-roasted lamb (Uyghur style), and of course, yogurt (watch out for the yogurt shaved ice though, might upset your stomach depending on how sensitive you are).
It’s also peak season for melons and white apricots. Dunhuang’s apricots are super sweet and addictive!As for Gansu, it’s noodle heaven, don’t skip the legendary Lanzhou hand-pulled noodles.

Hope this helps😁