Home
Weather Dublin
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
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
A graphic for World Meteorological Day featuring weather symbols.
Monday 23 March 2026

World Meteorological Day

Monitor today, protect tomorrow
Split image showing a warning map of the UK and Ireland on the left and a wind forecast map on the right with strong gusts around 40–55 mph, overlaid with a windsock warning symbol.
Tuesday 24 March 2026

Gales return

Increasingly gusty into midweek
On the left is the weather radar showing snowfall in the Alps; on the right is a wintry mountain landscape.
Wednesday 25 March 2026

Plenty of fresh snow

A return to winter in the Alps
All weather news
This might also interest you
plit image showing a double rainbow over a rocky shoreline on the left and sheep grazing in a green field under stormy clouds on the right.
Sunday 2 November 2025

Your weather - Your shots

Mixed conditions on an unsettled week
Illustration of white and yellow fireworks on a blue background.
Wednesday 31 December 2025

Hello 2026

Happy New Year
Outline of Santa Claus with a yellow and white hat, "Ho-Ho-Ho" next to the outline above a Christmas tree.
Thursday 25 December 2025

Merry Christmas!

Wishes from Weather & Radar
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

facebooktwitteryouTubelinkList