The data pin must be connected to a digital pin. You will want to place a 10K resistor between VCC and the data pin, to act as a medium-strength pull up on the data line. The Arduino has built in pullups you can turn on but they re very weak, about 20-50K. Use the Adafruit library from Github. To download: click the green Clone or download button in the top right corner and choose to Download ZIP. First uncompress the downloaded folder and then rename it DHT. Check that the DHT folder contains DHT.cpp and DHT.h. Place the DHT library folder your /libraries/ folder. Turns out the folder also contains a hidden folder .github which needs to be deleted.

The DHT library needs the Adafruit sensor abstraction layer. This layer can be installed in the same as described above. The name of the library need not be adapted.

After changing the settings to the right sensor type in the example sketch, that sketch runs, right out of the box in my configuration.

This sensor is not suitable for a project that might face a 100% air humidity like my flora project. Ordered now is it s better brother, the DHT22. Hopefully that one handles intense moisture better. This air sensor turns out to be vulnerable to high humidity and stops functioning after an hour. Maybe its high-end brother functions better.