Yes, but mostly over the last 100–150 years rather than every single year right now. Height gains are driven mainly by better nutrition, healthcare, and living conditions, and in many rich countries this trend has largely leveled off.
Long‑term trend
Over the past century, average adult height worldwide has increased by about 10 centimeters (around 4 inches) for both men and women, comparing people born around 1900 with those born near 2000. In some countries, such as South Korea and Iran, average adult height has increased by more than 16–20 centimeters over that period.
Why heights increased
The main reasons are environmental, not genetic evolution over such a short time. Key factors include improved childhood nutrition, reduced infectious disease, and better medical care and sanitation, which allow children to reach more of their genetic height potential.
What is happening now
In many high‑income countries, average height has plateaued since roughly the late 20th century, suggesting those populations are near their current genetic and environmental limits. In several low‑ and middle‑income regions, heights are still increasing slowly or have even stalled or declined where nutrition and health conditions have worsened.
Differences between countries
Countries with strong public health systems and good access to food, such as many European nations, tend to have taller average adult heights than countries with persistent undernutrition or high childhood disease burdens. For example, the gap between the tallest and shortest national averages is close to 20 centimeters and has not disappeared over the last century.