However, the upward trend in seasonally-adjusted traffic has slowed down since January 2016.
Passenger capacity, measured in available seat kilometres (ASKs), increased by 5.6%, while the load factor fell by 0.3% points to 80.7%.
IATA director general and CEO Tony Tyler said: “The demand for travel continues to increase, but at a slower pace.
“The fragile and uncertain economic backdrop, political shocks and a wave of terrorist attacks are all contributing to a softer demand environment.”
Compared to June, the international passenger demand rose by 5% during the same month this year.
Regions in Latin America revealed an increase in international passenger demand, while capacity rose by 6.4%, causing load factor to slide 1.1% points to 79.4%.
The IATA data demonstrated a growth of 5.7% in the demand for domestic passenger traffic in June 2016 compared to June 2015.
Capacity rose by 4.3%, causing load factor to rise to 83.2%.
With the exception of Brazil, all markets demonstrated an increase in passenger travel demand.
Tyler added: “The latest figures show that aviation and aviation related tourism delivers $2.7 trillion in economic impact and supports some 62.7 million jobs worldwide.”
IATA has also released data for global air freight demand in June 2016, revealing a year-on-year growth of 4.3% in freight tonne kilometres (FTK), which was the fastest pace of growth over the past 14 months.