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 longest day of the year. Summer solstice. . . Sunday 21 June 2026
Split image showing crowds gathered at Stonehenge at dawn beneath a hazy sunrise sky on the left, and a UK and Ireland temperature map on the right with temperatures reaching 30 °C near London and a thermometer icon highlighting hot conditions.
Sunday 21 June 2026

Summer solstice

The longest day of the year
Glaciers unprepared for coming heatwave. Little snow protection. . . Wednesday 17 June 2026
On the left is a webcam image of the Aletsch Glacier; on the right is the temperature radar, which shows the heat distribution in the Alps.
Wednesday 17 June 2026

Little snow protection

Glaciers unprepared for coming heatwave
Rising UV levels at the end the week. Mostly to the south. . . Wednesday 17 June 2026
Split graphic showing a UK temperature map with temperatures reaching 30°C near London on the left and a person applying sunscreen in bright sunshine on the right, with a UV warning symbol highlighting elevated ultraviolet levels.
Wednesday 17 June 2026

Mostly to the south

Rising UV levels at the end the week
All weather news
This might also interest you
Storm Chandra makes impact. Severe gales & heavy rain. . . Tuesday 27 January 2026
Split image showing strong winds over the UK on a forecast map and widespread rain and snow on a weather radar map.
Tuesday 27 January 2026

Severe gales & heavy rain

Storm Chandra makes impact
Unsettled conditions into the weekend. Breakfast brief. . . Friday 29 August 2025
Weather map of the UK and Ireland showing scattered showers with cloudy patches across much of the region, especially around western and northern areas. Sunshine symbols appear over London, Cardiff, and parts of southern England, while temperatures range from 17°C to 18°C in most places. Areas of heavier rain are visible over the Atlantic to the west.
Friday 29 August 2025

Breakfast brief

Unsettled conditions into the weekend
A frozen start to the weekend. Icy conditions. . . Friday 13 February 2026
UK temperature map dated 14.02 showing widespread subzero values in blue shading, with readings such as −4 in Glasgow, −3 in Dublin, and −2 in London, alongside a blue thermometer icon.
Friday 13 February 2026

Icy conditions

A frozen start to the weekend
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