Home / Editor's Pick /

Meteorological vs astronomical autumn: which is it?

17:00
3 September 2025

Season start date
Meteorological vs astronomical autumn

© shutterstock / Volodymyr TVERDOKHLIB

You may be thinking that autumn doesn't start until later in September, and you wouldn't be wrong thinking this. There are two separate dates which can be used to define the start of the season.

Astronomically, the start of autumn takes places on the autumn equinox, when the length of day and night are the same in all parts of the world.

It is defined by the Earth's axis and orbit around the sun, and the exact date varies slightly each year.

This year, the autumn equinox falls on September 22nd at 07:19 pm BST, with the astronomical autumn running until December 21st.

Meteorologically, seasons are a fixed date because it is statistically easier to process the data by taking four equal quarters for each of the four seasons.

The meteorological autumn in the Northern Hemisphere is made up of September (starting on the 1st), October, November, with meteorological winter beginning on December 1st.

While the days are really getting shorter and cooler for us, the opposite is true for those in the Southern Hemisphere.

Learn more about our seasons in our weather explained video here:

What weather does autumn hold for us?read more
More on the topic
Split image with wind radar showing gust of 108 mph on the left, and wind radar showing Hurricane Melissa over Jamaica on the right.
Thursday, 1 January 2026

July to December

2025: The year in weather
Split image showing a family and children playing and sledding on a snowy field with winter hills on the left, and a UK weather forecast map on the right with sun and cloud icons, city temperatures, and cloud cover over northern Scotland, divided by a curved white line.
Wednesday, 24 December 2025

Unlikely this year

Defining a White Christmas
Tsunami damage
Friday, 26 December 2025

On this day...

The 2004 Boxing Day tsunami
All weather news
This might also interest you
Wednesday, 27 August 2025

Breakfast brief

Frontal system brings heavy rain
Illustration of white and yellow fireworks on a blue background.
Wednesday, 31 December 2025

Hello 2026

Happy New Year
Sunday, 24 August 2025

Your weather - Your shots

Mammatus clouds widely spotted
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwittertikToklinkList