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
Slow moving rain brings flooding. More alerts live. . . Thursday 27 August 2026
Weather radar at 11:00 on 27.08 showing widespread heavy rain from Liverpool through the Midlands to eastern England, with an arrow indicating rain moving north.
Thursday 27 August 2026

More alerts live

Slow moving rain brings flooding
Violent thunderstorms mark summer's end. Hail and gusts of wind. . Weather Videos. Thursday 27 August 2026
Severe thunderstorm warning map showing a level 3 red zone from eastern France toward Belgium, surrounded by orange and yellow alerts extending into western Germany.
Weather VideosThursday 27 August 2026

Hail and gusts of wind

Violent thunderstorms mark summer's end
Extreme heat in Italy. Up to 45 degrees. . . Wednesday 26 August 2026
Split screen. On the left, a temperature map of Italy. On the right, a view of Taormina and Mount Etna
Wednesday 26 August 2026

Up to 45 degrees

Extreme heat in Italy
All weather news
This might also interest you
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
Historic Storm Éowyn arrives. On this day.... . . Saturday 24 January 2026
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday 24 January 2026

On this day...

Historic Storm Éowyn arrives
A stormy week in the skies above. Your weather - Your shots. . . Sunday 30 August 2026
Split image showing lightning branching beneath dark storm clouds above rooftops on the left and an orange-pink sunset over a calm sea on the right.
Sunday 30 August 2026

Your weather - Your shots

A stormy week in the skies above
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