Meteorologists and climatologists use fixed three-month periods to simplify record-keeping and data comparison. These seasons always start on the first day of their respective months. Meteorological Versus Astronomical Seasons | News
: These groupings more closely match the actual temperature patterns observed on Earth. For example, June, July, and August are typically the three warmest months of the year, fitting the logical definition of "summer".
The changing seasons are caused by the Earth's tilt on its axis, which is approximately 23.5 degrees. As the Earth orbits the Sun, its tilt causes the amount of sunlight that reaches the planet to vary throughout the year. This variation in sunlight leads to the changing temperatures, daylight hours, and weather patterns that we experience during each season.
Meteorologists and climatologists adopted the meteorological system for data consistency. Because the astronomical seasons vary in length (from 89 to 93 days), comparing temperature data from one year to the next becomes statistically difficult when the season lengths change. By splitting the year into clean three-month blocks (spring: March, April, May), scientists at NOAA and the World Meteorological Organization (WMO) can accurately compare climate trends month-to-month and year-to-year. months for the seasons verified
Spring is the season of renewal, bringing milder temperatures, increased rainfall, and the blooming of plants 0.5.3 .
| Season | Meteorological Months (Southern Hemisphere) | | :--- | :--- | | | December, January, February | | Autumn (Fall) | March, April, May | | Winter | June, July, August | | Spring | September, October, November |
It’s simple. Meteorological spring always starts on March 1st, making it much easier to compare weather patterns from year to year without worrying about shifting equinox dates. 2. The Astronomical Calendar (The Nature Way) For example, June, July, and August are typically
Because a year is not exactly 365 days, the exact dates of these transitions shift by a day or two each year. Northern Hemisphere
and groups months by temperature cycles [23, 24, 28]. In the Northern Hemisphere, this is the most common way to track seasons: March, April, May Awakening and renewal June, July, August Warmest temperatures September, October, November Cooling and harvest December, January, February Coldest temperatures 2. The Astronomical Seasons (Sun-Based)
| Season | Verified Start (Event) | Verified End (Event) | Months Spanned | | :--- | :--- | :--- | :--- | | | March Equinox (Mar 19-21) | June Solstice (Jun 20-21) | Second half of March, all of April & May, first half of June | | Summer | June Solstice (Jun 20-21) | September Equinox (Sep 22-23) | Second half of June, all of July & August, first half of September | | Autumn | September Equinox (Sep 22-23) | December Solstice (Dec 21-22) | Second half of September, all of October & November, first half of December | | Winter | December Solstice (Dec 21-22) | March Equinox (Mar 19-21) | Second half of December, all of January & February, first half of March | This variation in sunlight leads to the changing
Nature is dormant, making it a time for resting, introspection, and, in many cultures, festivals and holiday celebrations 0.5.2.
The occurs around September 22 in the North and March 20 in the South.
Here is the verified breakdown of months for the Northern Hemisphere according to the two official systems.
Fall, or autumn, is the transitional season that brings cooling temperatures and prepares the environment for winter 0.5.3.
The question of does not have a single answer—it has two verified answers, each authoritative for different purposes. If you are speaking meteorologically, the months are clean, fixed blocks (Mar-May, Jun-Aug, Sep-Nov, Dec-Feb). If you are speaking astronomically, the seasons start on equinoxes and solstices, spilling across month boundaries.