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
The monsoon has India firmly in its grip. Severe thunderstorms. . . Thursday 9 July 2026
Satellite map of South Asia showing the weather situation over India. An arrow marks a low-pressure system over western and central India, which is causing heavy showers and thunderstorms. Thick clouds and rainfall extend across large parts of India as far as the Himalayas and into Bangladesh. Over Pakistan and south-eastern Iran, however, it is mainly sunny and hot, with temperatures exceeding 40 degrees.
Thursday 9 July 2026

Severe thunderstorms

The monsoon has India firmly in its grip
Cooler nights and lower dew points. Less oppressive heatwave. . . Thursday 9 July 2026
Split image showing the London skyline in hazy golden sunset light in the left and an overnight temperature map of the UK and Ireland on the right, with minimum temperatures ranging from 13°C in northeast Scotland to 18°C in southern England.
Thursday 9 July 2026

Less oppressive heatwave

Cooler nights and lower dew points
Forest fires rage in southern Europe. Drought and wind. . . Monday 6 July 2026
Split screen. On the left, a weather map of France and Spain showing the plumes of smoke from the forest fires. On the right, a fire-fighting aircraft in action.
Monday 6 July 2026

Drought and wind

Forest fires rage in southern Europe
All weather news
This might also interest you
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
Seasonal warmth between spring thunder. Your weather - Your shots. . . Sunday 19 April 2026
Split image showing coastal sunset with layered lenticular clouds over rooftops and palm trees on the left, and a green valley with river and hills under soft daylight on the right.
Sunday 19 April 2026

Your weather - Your shots

Seasonal warmth between spring thunder
New records for England and Wales. Broken again tomorrow?. . . Thursday 25 June 2026
Temperature map of southwest Britain on 25.06 showing extreme heat across southern Wales and southwest England, with Bute Park in Cardiff highlighted at 34.2°C and Yeovilton at 36.4°C amid widespread deep red heat zones.
Thursday 25 June 2026

Broken again tomorrow?

New records for England and Wales
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