You may have noticed people discussing “summer” before the summer solstice has occurred.
That’s because astronomical and meteorological summer follow different cycles.
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Meteorological summer
Meteorological summer is a fixed period from June 1 to Aug. 31.
Meteorologists use this system as it is simpler for record-keeping and weather analysis. With meteorological summer spanning these three months continuously, comparing trends from year to year is easier.
This structure also helps climatologists track long-term weather patterns, such as average temperatures or rainfall, because they can rely on a predictable, uniform time frame.
Astronomical summer
Unlike meteorological summer, the summer solstice date can vary slightly each year because the Earth’s orbit isn’t perfect. While this marks a key point in Earth’s tilt, the actual weather on the ground may not match the “official” start of summer.
The Earth orbits the sun in approximately 365.25 days. That extra quarter of a day accumulates to an additional day every four years, known as a leap year. This slight shift causes the solstices and equinoxes to occur on different dates each year.
The summer solstice is considered the official start of summer in the Northern Hemisphere. It occurs at 9:42 p.m. on June 20, marking the longest amount of daylight and shortest night.
Why this matters
The main difference is that meteorological summer provides a consistent framework for analyzing and comparing weather patterns each year. In contrast, the summer solstice highlights the Earth’s movement and tilt in relation to the sun.
For meteorologists, meteorological summer is crucial when forecasting temperatures, storm trends or other long-term weather patterns. On the other hand, the summer solstice is a milestone for astronomers and anyone interested in the Earth’s changing relationship with the sun.
Which is more important
The summer solstice and meteorological summer are both important, but they highlight different aspects of the arrival of summer.
Whether you’re celebrating the seasonal milestone or analyzing weather trends, each event offers a unique perspective on the changing seasons, bringing us closer to the warmth and sunshine of summer.
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