Hailun's spring is marked by gradual warming, with temperatures rising from around 5°C in early March to a high of 12°C by the end of the month. April brings further increases, with an average temperature range of 10-18°C. Summer months are warm and humid, with July highs often reaching above 25°C, while August sees a slight dip to averages of 20-23°C. Autumn is characterized by cooling temperatures, with September averaging around 15-20°C. Winter brings cold snaps, with January temperatures ranging from -10 to -5°C.