Johu (調候) is the work of adjusting a chart’s temperature and humidity. When reading a chart, the season you were born in matters as much as the count of characters. The same eight characters receive completely different prescriptions in midsummer and midwinter. A hot chart first needs water to cool it; a frozen chart first needs fire to thaw it. This simple principle is the first criterion of interpretation in the classical tradition.
Johu — a chart has a felt temperature
Among the eight characters, the month branch, which holds the month of birth, sets the chart’s season. The tradition reads this season as cold or warm, dry or damp (寒暖燥濕). If a person is a plant, the natal chart is the variety and the season is the climate. Even the best variety struggles in the wrong climate. That is the johu view: before weighing the strength of the characters, match the temperature.
The grain of each season
Spring-born (寅·卯·辰 months) are born inside growing energy, good at beginnings and growth. Summer-born (巳·午·未 months) sit on a board full of heat, strong in expression and drive, but whether there is Water to cool them is the key. Autumn-born (申·酉·戌 months) are born inside the energy of gathering and sorting, with accurate judgment. Winter-born (亥·子·丑 months) belong to the season of storage and reflection, deep, but whether there is Fire to warm them is the first question of interpretation.
Same season, different day master — the most urgent character for ten combinations
Johu does not stop at the season; it pairs the season with the day master. The classical text Gungtong Bogam (窮通寶鑑) organizes the “most urgent character” for each of the ten day masters in each of the twelve months. The combinations met most often, in summary:
- Summer-born Wood day masters (甲·乙) — a tree standing on a hot board. Water (Gye) to keep it from drying out comes first, and Gap Wood uses Jeong Fire and Gyeong Metal as support (per Gungtong Bogam). With water, a summer tree grows most luxuriantly of all.
- Summer-born Metal day masters (庚·辛) — metal that melts easily. In the 巳 and 午 months water (Im·Gye) is urgent to cool it; entering the 未 month the prescription shifts toward refining the metal with Jeong Fire and Gap Wood. Without water, the talent is there but the stamina to last is not.
- Winter-born Fire day masters (丙·丁) — a small fire on a frozen board. For Jeong Fire, Gap Wood (with Gyeong Metal) as fuel comes first; for Byeong Fire, Im Water and Gap Wood are read together. A winter fire without wood shows up as motivation that keeps going out.
- Winter-born Water day masters (壬·癸) — the season when water turns to ice. Fire (Byeong) to thaw it is urgent, and Im Water is read with Mu Earth to hold back the flood. Without fire, thinking hardens and the body sags. The person changes in a Fire year.
- Winter-born Wood day masters (甲·乙) — a winter tree. Fire comes before water. Eul Wood wants sunlight (Byeong); Gap Wood uses Jeong Fire and Gyeong Metal with Byeong added. A structure waiting for spring, so growth concentrates in Fire and Wood periods.
- Spring- and autumn-born — not temperature extremes, so the balance of forces (eokbu) often comes before johu. But late autumn (戌 month) is dry and late spring (辰 month) damp, so humidity may need adjusting.
Find your day master and month branch in the list above and “which character is welcome in my chart” comes out in one line. The combinations above are an introductory digest of the johu prescriptions in Gungtong Bogam; in an actual reading, the remaining characters change the priority.
Why johu is the first criterion
If the eokbu view that measures strong and weak is a scale of forces, johu is a matter of survival environment, so it comes first. A frozen chart cannot draw out its strength however strong it is, and a parched chart burns even its good characters. That is why the classical tradition fixed the most urgent character for each pairing of season and day master in advance. Know what is urgent in your chart and half the reading is done.
When the cycle fills in the temperature
A chart short on johu is nothing to worry about. The ten-year and annual cycles flow like seasons and bring the needed temperature. When a Fire period comes to a winter chart, things loosen the way a body thaws; when a Water period comes to a summer chart, impatience settles and judgment clears. The stretch when “life is strangely livable these days” is often the one where the temperature lined up.
Know the reverse too. A Fire year stacked on a summer chart, a Water year stacked on a winter chart: these are stretches where the temperature goes to an extreme. In such years, weight condition management over results; that is the trick of managing them. It is exactly why 2026 Byeong-o was so draining for summer-born Fire day masters.
How to read common situations — consultations
“I was born in summer and have no Water at all. Is that serious?” Not serious; a structure with a clear prescription. A summer chart without water has nothing to cool the heat, so impatience and burnout repeat easily, but by the same measure the feeling is vivid when a Water period arrives. In daily life, cooling habits (sleep, rest, activity near water) are the prescription, and a Water day-master partner is a good match. For these people, “you’re so passionate” is both a compliment and something to manage.
“I’m winter-born and get depressed every winter. Is it my chart?” If you are winter-born with weak Fire, it is true that the season amplifies the natal grain. For these people, deliberately raising activity and light in winter is how johu is moved into daily life. But if the heaviness lasts a long time, a professional comes before saju. Saju is used only as far as knowing “I’m a structure that sags more in winter.”
“A friend born on the same day has a completely different personality.” Same johu but a different hour changes the temperature. Even among summer-born, someone with 亥 or 子 (water) in the hour branch and someone with 巳 or 午 (fire) there have different felt temperatures, and that difference shows up as differences in personality and condition. Johu is read not from the month branch alone but from the temperature of all eight characters.
Frequently asked questions
Q. I was born in summer. Is a Fire period bad? Not bad so much as a period when heat is added. Results come hot, but so does burnout. In such stretches, the trick is to consciously keep buffers like rest and hydration. With water in the natal chart, the period can actually become one of activity, so check for water first.
Q. Is johu the same for everyone born in the same season? The seasonal base is the same, but the remaining characters change the temperature. Among summer-born, a chart with plenty of water characters and one without feel different. That is why the principle is to read johu from all eight characters. The day-master list above is the starting point; the remaining characters settle the conclusion.
Q. Where do I check my chart’s temperature? Look at the earthly branch of the birth month (the month branch) on a manseryeok chart to find the season. To go on to which character is urgent, a full natal reading is needed. Simply knowing that 巳·午·未 is summer and 亥·子·丑 is winter lets you find your combination in the list above.
In closing
When saju study feels hard, johu is the most intuitive entrance. Knowing just which season you were born in and which energy is welcome, you start to get a feel for the rhythm of your condition and the periods when things go well.
If you want to know your chart’s season and temperature, and whether the current cycle warms or cools you, check it in Sajuping (sajuping.ai), an AI saju companion built on manseryeok calculation.