The Balkans are a solid option. Countries like Bosnia & Herzegovina, Montenegro (especially the mountains around Durmitor), and northern Albania are affordable and have great nature without the tourist crush you'd get in Western Europe. The Tatras in Slovakia and Poland are also a great choice for hiking and avoiding crowds.

If you’re open to Latin America, the Andean regions of Peru, Ecuador, and Bolivia are in their dry season and won’t be too hot due to elevation. These areas are some of the cheapest places to backpack, and you’ll get a mix of mountains, indigenous culture, and cheap food. Patagonia is too cold in July, but you could look at the Chilean Lake District if you want something cooler.

Georgia (the country) is another underrated summer destination. Tbilisi gets warm, but the Caucasus Mountains are cool and perfect for trekking.

For Asia, northern Japan (Hokkaido) is a solid bet for escaping the heat, and it’s way less crowded than Tokyo/Kyoto in peak season. Flights to Japan can be expensive, but once you’re there, you can keep costs down with hostels, highway buses, and discount rail passes.

If you want something completely off the usual path, Mongolia is another option. It’s cool in summer, affordable once you’re there, and offers a unique mix of nomadic culture and open landscapes.