SBS News

News > Society

"Hardly Seen This Summer... Autumn Mosquitoes' Swarm as Weather Turns Cooler

Han Sung-hee

Published : Sep 5, 2026 8:44 AM

Video

[Anchor]
 
Many of you may have noticed that while the weather has turned cooler recently, mosquitoes actually seem to be on the rise. This is attributed to autumn temperatures rising due to climate change, compounded by this summer's record-breaking heatwaves and monsoons. Possibilities are also being raised that their numbers could increase even further starting next week.

Reporter Han Sung-hee has the story.

[Reporter]

On the 2nd, after rain fell for three consecutive days in Seoul and finally stopped, collection work is underway for mosquitoes caught in the city's mosquito monitoring equipment.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: (Can you see mosquitoes flying around here now?) Yes, that's right. Looking at it now, mostly the yellowish ones are likely to be Culex pipiens mosquitoes.]

Even in just about 10 minutes, mosquitoes swarm to various spots.

[Two of them landed right here.]

The collected mosquitoes are moved to a laboratory for analysis.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: These are house mosquitoes. They are species that can be frequently seen indoors.]

Yesterday (the 4th), an average of over 51 mosquitoes per site were captured across 55 equipment locations in Seoul in a single day.

This is a 1.5-fold increase compared to a week ago.

As poikilothermic animals, mosquitoes are most active in spawning and activities when temperatures are around 25 degrees Celsius (77 degrees Fahrenheit). As autumn temperatures rise due to climate change and other factors, autumn mosquitoes have been showing a trend of increasing over time.

While mosquitoes were overwhelmingly numerous in August back in 2015, September mosquitoes have surpassed August mosquitoes starting in 2018.

Particularly this year, puddles dried up due to heatwaves and drought, reducing mosquito spawning in early August. However, precipitation increased after mid-August, leading to an increase in spawning as well.

This is because rainwater pooled in various places, creating breeding grounds for mosquitoes.

When mosquitoes lay eggs in these puddles formed after rain, the eggs grow into adult mosquitoes two weeks later, increasing the population.

As the so-called "secondary monsoon" ended this week, there is a possibility that the mosquito population will increase further.

[Kang Hyojung / Researcher, Sahmyook University Institute of Environmental Ecology: (In previous years as well), as the heatwaves subsided and temperatures dropped slightly, mosquitoes showed a trend of increasing little by little. (This year), I think mosquitoes will likely increase around mid-to-late September.]

Simply getting rid of stagnant water around the house on a regular basis to cut off the environment where larvae can grow helps reduce the mosquito population.

(Video Journalist: Yoon Hyung | Video Editor: Kim Yoon-sung)