June marks the beginning of summer. The maximum temperature reaches 29 °C (84 °F) and the minimum temperature is 21 °C (70 °F). It is a little hot, and summer clothing such as shorts, T-shirts, skirts, etc., is enough. Bring long-sleeve clothing for cool nights. It begins to rain more so when you go out, carry an umbrella with you.
The Chinese Dragon Boat Festival (the 5th day of the 5th month in the Chinese lunar calendar) usually takes place during June. There are dragon boat competitions and other celebrations to enjoy if you visit Nanjing during this special occasion.