Used by meteorologists for consistent data comparison. Chinese Solar Calendar (24 Solar Terms) Divides the year into 24 periods (~15 days each), based on sun longitude. Seasons each contain 6 terms.
Note: Dates vary slightly due to leap years. Simpler for climate records: split calendar into 3-month blocks based on temperature cycles. seasons by calendar
| Season | Northern Hemisphere | Southern Hemisphere | Astronomical Markers | |--------|--------------------|--------------------|----------------------| | Spring | March equinox (Mar 19–21) to June solstice (Jun 20–22) | September equinox (Sep 22–23) to December solstice (Dec 20–22) | Increasing daylight | | Summer | June solstice to September equinox | December solstice to March equinox | Longest day | | Autumn | September equinox to December solstice | March equinox to June solstice | Decreasing daylight | | Winter | December solstice to March equinox | June solstice to September equinox | Shortest day | Used by meteorologists for consistent data comparison