This site uses cookies for ad optimization and service analytics. Privacy Policy
Daeseo means "greater heat," the hottest time of the year. Overlapping the dog-day heat, the swelter reaches its peak.
Daeseo, around July 23, is when the heat wave rages. Falling near the mid-summer dog day, it is the hottest stretch.
Along with the heat come frequent showers and typhoons. Fruit ripens and crops mature, while drought and flood damage are also feared.
People beat the heat with warming tonics like samgyetang (ginseng chicken soup), fighting heat with heat. Watermelon and melon are at their sweetest and most plentiful now.
Daeseo (Greater Heat) begins when the Sun reaches 120° of ecliptic longitude and is the last term of summer. · First pentad, 腐草爲螢 — rotting grass turns into fireflies. · Second pentad, 土潤溽暑 — the soil is damp and the heat is muggy. · Third pentad, 大雨時行 — heavy rain pours down from time to time. The first pentad is an old explanation born from watching fireflies rise out of damp undergrowth and concluding that the grass had turned into them. In reality the larvae grow in water or moist soil and fly up after pupating, but the observation that fireflies come from damp places was accurate. The second and third pentads describe the nature of the heat: Daeseo's heat is not dry but a steam-bath heat from waterlogged ground, and the moisture it builds up comes down all at once in cloudbursts. That matches late July in Korea closely, when humid heatwaves and sudden local downpours alternate after the monsoon ends.
Daeseo is also when summer holidays peak in Korea. Before you leave, clear the fridge of anything that spoils quickly, and if the house will be empty for several days, be sure to empty the food-waste bin so you don't come home to fruit flies and smells. Peaches move into their season now, and waxy corn, fresh green soybeans and summer eggplants are at their height. Tropical nights — when the temperature stays at or above 25°C all night — tend to run on at this point, so switch the bedroom to summer mode. Use bedding that doesn't cling, such as rayon (ingyeon) or hemp, and take a lukewarm shower an hour or two before bed to help the body shed heat. Rather than running the air conditioner hard all night, set a sleep timer, and turn the fan toward the wall so it circulates air instead of blowing directly on you.
A Korean saying has it that 'at Daeseo even a goat's horns melt.' It is an exaggeration — heat strong enough to soften something as hard as horn — and it captures how people experienced Daeseo as the most sweltering point of the year. Daeseo lies close to jungbok, the middle dog day, and often sits right in the heart of the sambok heat, so in many years the saying hardly feels like an overstatement. Measuring the heat not against the human body but against something as solid as horn shows how heavily this term's heat weighed on people.
| Year | Begins at |
|---|---|
| 2024 | Jul 22, 16:44 |
| 2025 | Jul 22, 22:29 |
| 2026 this year | Jul 23, 04:13 |
| 2027 | Jul 23, 10:05 |
| 2028 | Jul 22, 15:54 |
Greater Heat is a jungi (中氣) rather than a jeol (節), so the Four Pillars month pillar does not change here. It marks the middle of a season.
Taking Greater Heat alone: it fell at Jul 22, 22:29 in 2025 and at Jul 23, 04:13 in 2026 — roughly 5.7 hours later. The date jumps back a day in 2028 because that is a leap year, so February 29 falls before the term begins.
By longitude, Greater Heat sits at 120° and the next term Start of Autumn at 135° — about 15 days apart.
Eat dog-day tonics like ginseng chicken soup
Watch for heat illness in the heat wave
Enjoy seasonal fruit like watermelon and melon
Get plenty of water and rest
Adjacent terms:
Explore related fortunes
Greater Heat is the 12th of the 24 solar terms, falling around July 23. The "greater heat"—the hottest term of the year. The dog-days heat peaks.
Daeseo means "greater heat," the hottest time of the year. Overlapping the dog-day heat, the swelter reaches its peak.
Eat dog-day tonics like ginseng chicken soup Watch for heat illness in the heat wave Enjoy seasonal fruit like watermelon and melon Get plenty of water and rest