Lucas (7th) & Lucy (4th) · 2026–2027

24 Solar Terms & Seasonal Rhythms

The 24 Solar Terms (二十四节气) organize a full year of scientific observation, beginning at 大暑 on July 22, 2026 — where the action research project ended — and closing the cycle a year later.

Why the Solar Terms

The 24 Solar Terms contain rich knowledge of astronomy, climate, and phenology, and are recognized as UNESCO intangible cultural heritage. Each term offers an occasion for embodied waiting (候), data collection, and scientific documentation.

The framework mirrors the seasonal round used in Indigenous science education, where observation of natural cycles plays a central role in a way of life. Earth science, life science, and physical science are integrated through direct observation.

Summer 2026

Continuation of the action research project

Solar TermDate4th Grade Focus7th Grade FocusDocumentation
大暑 Great HeatJul 22Hottest temperatures; how heat affects plants and animalsThermal energy transfer; heatwave patterns (MS-PS1-4)Temperature tracking; weather journal
立秋 Beginning of AutumnAug 7Signs of autumn; leaves changingTemperature shift; plant senescence (MS-LS1-5)Seasonal journal; leaf observations
處暑 End of HeatAug 23Cooling temperatures; weather changesWeather patterns; air mass interactions (MS-ESS2-5)Weather record; temperature graph
白露 White DewSept 7Dew on grass; water on surfacesDew formation; states of matter (MS-PS1-4)Dew measurement; observation journal
秋分 Autumnal EquinoxSept 22Equal day and nightEarth's tilt and orbit; seasons (MS-ESS1-1)Day/night length recording
寒露 Cold DewOct 8Cooler temperatures; frost beginsTemperature decline; plant dormancyFrost record; temperature tracking
霜降 First FrostOct 23First frost; plants preparing for winterPhenology; ecosystem changes (MS-LS2-1)First frost date; plant journal

Winter 2026

Deep cold, snow, and the returning light

Solar TermDate4th Grade Focus7th Grade FocusDocumentation
立冬 Beginning of WinterNov 7Shorter days; animals preparingEarth's orbit; light patterns (MS-ESS1-1)Light tracking; animal behavior notes
小雪 Light SnowNov 22Snow begins; cold weatherSnow formation; states of matter (MS-PS1-4)Snow observation; weather journal
大雪 Heavy SnowDec 7Measuring snow; winter weatherPrecipitation; water cycle (MS-ESS2-4)Snow measurement; data collection
冬至 Winter SolsticeDec 21Shortest day of the yearEarth's tilt; solstice (MS-ESS1-1)Solstice observation; daylight graph
小寒 Slight ColdJan 6How animals survive the coldAnimal adaptations; thermal energy (MS-LS1-4)Temperature tracking; adaptation notes
大寒 Great ColdJan 20Deep winter; snow and iceWinter ecosystems; energy transfer (MS-LS1-6)Temperature tracking; ecosystem observation

Spring 2027

Waking, melting, and growing

Solar TermDate4th Grade Focus7th Grade FocusDocumentation
立春 Beginning of SpringFeb 4Days getting longer; signs of springSeasonal shift; Earth's orbit (MS-ESS1-1)Light tracking; observation journal
雨水 Rain WaterFeb 19Rain and melting snowWater cycle; states of matter (MS-ESS2-4)Water cycle diagram; precipitation data
驚蟄 Awakening of InsectsMar 5Animals waking up; insects appearEmergence from dormancy; ecosystems (MS-LS1-4)Animal observation journal
春分 Spring EquinoxMar 20Equal day and nightEarth's tilt; equinox (MS-ESS1-1)Day/night recording
清明 Fresh GreenApr 4Plants growing; flowers bloomingWeather; plant growth (MS-LS1-5)Plant growth record; weather data
穀雨 Grain RainApr 20Rain helps plants growPhenology; photosynthesis (MS-LS1-6)Plant growth observation

Summer 2027

Completing the full-year cycle

Solar TermDate4th Grade Focus7th Grade FocusDocumentation
立夏 Beginning of SummerMay 5Warmer weather; plants growingPlant growth; energy flow (MS-LS1-5)Temperature graph; growth journal
小滿 Lesser FullnessMay 21Plants growing tall; bloomingPlant maturity; energy flow (MS-LS1-6)Plant growth observation
芒種 Grain in EarJun 5Crops growing; summer beginsPlant maturity; photosynthesis (MS-LS1-6)Observation notes; plant journal
夏至 Summer SolsticeJun 21Longest day of the yearEarth's tilt; solstice (MS-ESS1-1)Solstice observation; full-year comparison
小暑 Slight HeatJul 7Summer heat; warm temperaturesTemperature rise; thermal energy (MS-PS1-4)Temperature tracking
大暑 Great HeatJul 22Hottest days of summerHeatwave patterns (MS-PS1-4)Year-end comparison; full-year reflection

Documentation by Subject Area

Subject Area4th Grade7th Grade
Earth ScienceSeasonal observations, weather data, temperature tracking, day/night lengthFull data collection; solstice & equinox records; water cycle models
Life SciencePlant growth drawings; animal behavior observationsPhenology data; ecosystem analysis; photosynthesis notes
Physical ScienceTemperature tracking; states of matterStates of matter; thermal energy analysis
Scientific PracticesObservation and recording; drawing conclusionsData collection; measurement; graphing; comparative analysis

Grade-Level Differentiation

Element4th Grade7th Grade
ComplexitySimple observation and descriptionAnalysis, comparison, and data interpretation
WritingShort sentences; labeled drawingsData tables; graphs; written conclusions
ConceptsBasic plant/animal/weather observationsChemical reactions; energy transfer; genetics; evolution
Earth-Sun RelationshipObserving day/night and seasonsModeling Earth's tilt; analyzing solstices & equinoxes
Citizen ScienceParticipate and observeParticipate; analyze data; connect to climate change