Autumn Similar to Spring, Which Season Is More Comfortable for Outdoor Activities?

Korea Meteorological Administration Compares Spring and Autumn Sunlight Differences Over 29 Years

On the 21st, with a temperature difference of nearly 10 degrees in the Seoul area indicating early autumn weather, yellow cosmos flowers are in full bloom at the Wildflower Hill in Olympic Park, Songpa-gu, Seoul. Photo by Jinhyung Kang aymsdream@

[Asia Economy Reporter Hyunju Lee] Excluding the hot summer and cold winter, which season between spring and autumn is more refreshing and enjoyable for outdoor activities?

On the 26th, the Korea Meteorological Administration announced the results of an analysis of total solar radiation, total ultraviolet index, sunshine duration, and daily average humidity during spring (March to May) and autumn (September to November) from 1991 to 2009. The data was based on 45 observation points across South Korea.

Analyzing the total solar radiation and ultraviolet index over the past 29 years for spring and autumn, the average total solar radiation per square meter in spring was 1516.53 MJ, while in autumn it was 1040.53 MJ, showing that autumn solar radiation was 476 MJ less. The total ultraviolet index was also lower in autumn (5.2) compared to spring (6.5).

The reason why total solar radiation is stronger in spring than in autumn is that the sunshine duration is longer in spring. The average sunshine duration in spring is 640.7 hours, while in autumn it is 544.2 hours. In autumn, as the solar zenith angle gradually increases, starting from the autumnal equinox, the length of daylight shortens, reducing sunshine duration. Conversely, in spring, as the solar zenith angle gradually decreases starting from the vernal equinox, the length of daylight increases, resulting in longer sunshine duration.

Spring Solar Radiation, Ultraviolet Amount, and Sunshine Duration Higher than Autumn; Less Ultraviolet Impact on Skin

The daily average humidity in spring is 61%, while in autumn it is 70%. Since higher humidity reduces the amount of sunlight that penetrates, the amount of sunlight reaching the ground in autumn is less than in spring.

In other words, spring has higher solar radiation, ultraviolet amount, and sunshine duration compared to autumn, but lower humidity. Therefore, outdoor activities feel more comfortable in autumn than in spring.

Spring sunlight has a significant impact on skin that has been protected from ultraviolet rays during winter, whereas autumn affects skin that has been conditioned over the summer, so the impact is less. A Korea Meteorological Administration official stated, "In spring, since melanin pigment that protects against ultraviolet rays is not sufficiently produced, exposure to sunlight causes more severe skin damage. In autumn, however, melanin pigment has already accumulated during the summer, so skin damage may be less compared to spring."

This content was produced with the assistance of AI translation services.