There is no forecast for a cold snap on the day of the 2026 College Scholastic Ability Test (CSAT) on the 13th. However, the morning will be chilly and the afternoon will warm up, with a large temperature swing between day and night, so it would be best to layer thin clothes.
The Korea meteorological Administration said in an ad-hoc forecast briefing on the 10th that "the morning temperature, which is when most test-takers enter the test sites on CSAT day, will be around 5 degrees, so it will feel chilly," and "some areas may have fog, so extra caution is needed for morning road traffic safety."
However, during the day, temperatures will rise sharply to at least 15 degrees. An official at the Korea meteorological Administration said, "There will be a large temperature difference between day and night on the day," and added, "During the day, wearing thick clothes may feel hot, so it's important to adapt to temperature changes by wearing several thin layers that can be put on or taken off."
There is no "CSAT cold snap." On the morning of the 13th, the low will be 2–11 degrees and the daytime high will be around 14–19 degrees, which is about 1–4 degrees higher than average. To check detailed weather information near your test site, refer to the "2026 CSAT test site weather information" banner at the bottom left of the Korea meteorological Administration website.
Meanwhile, rapidly turning cold and then mild again has been repeating recently. This is the typical samhan saon (three cold days and four warm days) pattern in winter. This week, temperatures fell on Monday and Tuesday, the 10th–11th, and will recover starting on the 12th. The weather will be mostly clear on the 14th–15th, and on Sunday the 16th, temperatures will drop again with a chance of light rain.