The great debate: When does spring officially start, February 1 or March 1? 

A St. Brigid's Cross hangs from a tree at St Brigid's holy well in Co Kildare. February 1st marks St Brigid's Day which is seen by many in Ireland as the first day of Spring. Picture: Brian Lawless/PA Wire

Most Irish people believe that today, February 1, and St Brigid's Day, marks the start of spring.

This belief stems from a traditional Gaelic festival called Imbolc.

Imbolc lands about halfway between the winter solstice and spring equinox, and is one of four Gaelic seasonal festivals alongside Bealtine, Lughnasadh and Samhain.

Imbolc features in Irish literature dating back as far as the 10th century, it  and was associated with the lambing season, the idea of rebirth, and St Brigid. 

However, meteorologically, spring does not begin on February 1, but March 1 instead.

Met Éireann considers March 1 to be the start of spring "for meteorological and climatological purposes."

According to the national forecaster, December, January and February are winter months; March, April and May are the months of spring; June, July and August make up the summer months and the autumn months consist of September, October and November. 

Met Éireann say that this grouping is based on air temperature and is "a common grouping in the meteorological practice of many countries in the middle and northern latitudes."

Yet, as well as having meteorological seasons, we also have astronomical seasons which are grouped slightly differently again. 

Astronomical seasons are based on the position of the earth as it rotates around the sun, they are grouped using two equinoxes and two solstices.

"Astronomical seasons occur on slightly different dates year to year but generally around the same time period," Met Éireann said. 

For example, the astronomical spring season for 2023 is between March 20 - June 21, whilst astronomical spring 2024 is from March 20 - June 20.