2021 — Meteorological Seasons

In the Northern Hemisphere, the meteorological seasons are fixed as follows:

The traditional astronomical seasons are based on the Earth's tilt and orbit around the Sun. The four seasons are defined as: meteorological seasons

Meteorological seasons are a method of dividing the year into four distinct periods—Winter, Spring, Summer, and Autumn—based on the annual temperature cycle and the calendar month. Unlike astronomical seasons, which are defined by the Earth’s axial tilt and solstices/equinoxes, meteorological seasons are fixed to specific dates for consistency in climate analysis, weather forecasting, and statistical record-keeping. This report outlines the definition, timing, scientific rationale, advantages, and limitations of meteorological seasons. In the Northern Hemisphere, the meteorological seasons are

Key reasons for adoption:

This system aligns closely with the concept of . For example, the period of June through August typically encompasses the warmest months of the year in the Northern Hemisphere due to the delay in the atmosphere heating up (thermal inertia), despite the solstice occurring mid-way through this period. This report outlines the definition