Jul 23, 2026; Jul 23, 2027 (the moment the term begins, Beijing time).

What are the three pentads of Major Heat?

Pentad 1: 腐草為螢 (Fireflies rise from rotting grass (an old belief)); Pentad 2: 土潤溽暑 (The soil is damp and the heat is heavy); Pentad 3: 大雨時行 (Heavy rains come often).

Where is the Sun at Major Heat?

The Sun reaches ecliptic longitude 120° (entering Leo). Major Heat is a principal term (zhongqi) in summer.

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Major Heat

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Major Heat

大暑 · Dashu

Sun's longitude 120° · Principal term (zhongqi) · Summer · Jul 23, 2026

The hottest time of the year, with plenty of rain: heat and humidity arrive together.

The three pentads

腐草為螢Fireflies rise from rotting grass (an old belief)
土潤溽暑The soil is damp and the heat is heavy
大雨時行Heavy rains come often

Each solar term is split into three pentads of about five days, each marked by a sign in nature.

Customs

People drink herbal “dog-day” tea and dry ginger in the sun; on the Zhejiang coast villages send off a “Dashu boat”.

Sky file

Sun's longitude: 120°
Type: Principal term (zhongqi)
Season: Summer
Chinese month: 未 Wei month (Minor Heat to Start of Autumn)
Sun's position: Enters Leo
Dates: Jul 23, 2026 · Jul 23, 2027

Dates are in Beijing time.

Frequently asked questions

When is Major Heat?: Jul 23, 2026; Jul 23, 2027 (the moment the term begins, Beijing time).
What are the three pentads of Major Heat?: Pentad 1: 腐草為螢 (Fireflies rise from rotting grass (an old belief)); Pentad 2: 土潤溽暑 (The soil is damp and the heat is heavy); Pentad 3: 大雨時行 (Heavy rains come often).
What customs are associated with Major Heat?: People drink herbal “dog-day” tea and dry ginger in the sun; on the Zhejiang coast villages send off a “Dashu boat”.
Where is the Sun at Major Heat?: The Sun reaches ecliptic longitude 120° (entering Leo). Major Heat is a principal term (zhongqi) in summer.

For culture and fun: personality and tradition only, no predictions.