Daffodils are in flower, the days are getting longer, but what is the official first day of spring in the UK in 2023?


As soon as we edge into March, the age-old question of ‘when does spring start?’ begins to crop up. Whether you define the start of spring as trees coming into blossom or soil temperature warming up, we are all bound to seasonality, especially as gardeners.

Marking the start of spring by changes to the plants in our gardens is the phenological approach. But there are two other distinct definitions for the start of spring, the astronomical and the meteorological, which are determined by different factors.

What is the first day of spring 2023?

What is Astronomical Spring?

In astronomical terms spring begins with the vernal equinox. This is determined by the Earth’s orbit of the sun. When the sun crosses the equator line heading northwards, this marks the start of spring in the northern hemisphere. The date on which this occurs can vary slightly from year to year between the 19th and 21st of March. This year, the astronomical start of spring is the 20th of March 2023.

Prunus 'Accolade'
© Richard Bloom

What is Meteorological Spring?

The meteorological start of spring is marked by the first day of March every year. Changes in annual temperature determine when the meteorological seasons change, and the year is divided into four sections aligning with the Gregorian calendar. Under this system, spring lasts from the 1st of March to the 31st of May 2023.

Magnolia ‘Star Wars’. A recent and excellent cross between M. campbellii and M. liliiflora. It grows into a smallish tree and produces masses of pink flowers in spring just before the foliage emerges. 6m. AGM. RHS H5, USDA 5a-8b.
Magnolia ‘Star Wars’ © Jason Ingram

What is the first day of spring in gardening terms?

When it comes to your garden, it’s best not to get too hung up on dates and solar activity. Paying attention to the weather forecast and the average nighttime temperature will be the most important things when it comes to sowing seeds and moving tender plants back outside. If you’re really keen to divide up the year then consider March to be early spring, April to be mid spring and May to be late spring.

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Narcissus 'Monique'
© Jason Ingram


Molly Blair
Molly Blaireditorial and digital assistant

Molly is the Gardens Illustrated's editorial and digital assistant. She has a roof garden and has her RHS level 2.