In Ireland, the practice amongst the general populace is to classify the seasons in the following way:
- Winter – November, December, January
- Spring – February, March, April
- Summer – May, June, July
- Autumn – August, September, October
This is different to most other countries in the northern hemisphere, which generally classify each season as beginning a month and a half later than shown above.
In fact, the only other country in the world that shares a similar convention with Ireland is Japan.
Astronomical vs Meteorological Seasons
There are two equally valid ways of classifying seasons:
The Meteorological approach is based on average temperature. It takes the warmest three-month-period of the year as its Summer, and the coldest three-month-period as its Winter.
The Astronomical approach is based on average sunlight hours. It takes the brightest three-month-period as its Summer, and the darkest three-month-period as its Winter.
It’s not quite exact, however. In Ireland, the seasons start on the first day of the appropriate month. The actual astronomical seasons start roughly a week later than this. We can see this in Japan’s similar, but slightly different seasons:
- Winter – 8 November to 4 February
- Spring – 5 February to 6 May
- Summer – 7 May to 8 August
- Autumn – 9 August to 7 November
Usage in Ireland
Both approaches are valid in their respective fields, but it is the latter astronomical approach which is in general usage in Ireland.
We can see this reflected in the names we use for the months in our own language:
- Fómhair is the Irish word for Autumn.
- Meán Fómhair (September) translates literally as “The Middle of Autumn”.
- Deireadh Fómhair (October) translates literally as “The End of Autumn”.