WEATHER
Forecasters: 1 March
Meteorological spring runs from 1 March to 31 May. Fixed three-month seasons make long-term climate records easier to compare.
Compare the datesWHAT THE MET OFFICE SAYS
Spring has
two start dates.
Ask when spring starts and you can get two answers.
1 OR 20? both are right
8.08°C Average UK spring temperature, 1991–2020
- 1 March for weather
- Equinox for the sky
- Nature keeps its own time
- How March turns the seasons
Forecasters say 1 March. Astronomers say the equinox, around 20 March. For centuries, England even started its year in March. Here is how the dates fit together.
THE SHORT ANSWER
It depends
who you ask.
Three ways of marking spring.
Each one is useful for a different job.
SKY
Astronomers: the equinox
Astronomical spring starts at the vernal equinox, around 20 March. The exact date shifts a little each year with Earth's tilt and orbit.
Equal day and night?
SNOW
March can still bite
The Met Office says snow or sleet is statistically more likely in March than in December, so snow at Easter is not unusual.
See the numbersA QUICK DATE CHECK
Which start
of spring?
Pick a way of marking the start of spring to see where it comes from. The bar shows how fixed that date is from year to year.
Based on Met Office guidance, the US National Weather Service, Newcastle University and the Woodland Trust.
FOUR THINGS TO DO IN MARCH
Watch the season
turn for yourself.
March is a good month to notice how the seasons change. These simple habits connect what you see outside with the science behind it.
Note 1 March
Meteorological spring begins. Keep an eye on how cold the nights still are compared with the days.
Track the sunrise
After the equinox, daylight increases more quickly, with earlier sunrises and later sunsets.
Record a first sighting
Log the first leaf buds, butterflies or swallows you see with a citizen-science project such as Nature's Calendar.
Keep a coat handy
Snow or sleet is statistically more likely in March than in December, so spring can still turn wintry.
TWO NUMBERS WORTH KNOWING
Warmer than winter,
watched for centuries.
One figure on how warm a UK spring is on average,
one on how long people have recorded its signs.
8.08°C
Average UK spring temperature, 1991–2020
That compares with 4.09 °C for the average UK winter over the same years. Nights can stay cool in spring even as the sun climbs higher.
UK SPRING · MET OFFICE
1736
Year the seasonal wildlife record dates back to
Volunteers record events such as leaf buds bursting and the first swallows, helping scientists study how weather and climate affect the timing of nature.
NATURE'S CALENDAR · WOODLAND TRUST
The Met Office explains that Earth's axis is tilted at 23.5 degrees, and this tilt, as Earth orbits the Sun, causes the changing seasons.
EQUAL NIGHT?
Not quite
twelve and twelve.
The word equinox comes from Latin and roughly means equal night. But on the equinox itself, day is a little longer than night, because sunrise is timed from when the edge of the Sun's disc first appears, and the atmosphere bends sunlight so we see it before it has truly risen.
The day when daylight and darkness really are equal is called the equilux. It falls on a different date from the equinox and varies with latitude, according to the US National Weather Service.
Questions
Questions people ask
When does spring start in the UK?
It depends which definition you use. Meteorological spring runs from 1 March to 31 May. Astronomical spring starts at the vernal equinox, around 20 March.
Why do forecasters start spring on 1 March?
The Met Office splits the year into four fixed three-month seasons, which makes it easier to compare long-term climate records of temperature, rainfall and sunshine.
Are day and night equal on the equinox?
Roughly, but not exactly. Sunrise is timed from when the edge of the Sun first appears, and the atmosphere bends sunlight, so day is slightly longer. The truly equal day is called the equilux.
Is snow in March unusual?
No. The Met Office says snow or sleet is statistically more likely in March than in December, so snow at Easter is not unusual.
Did the year really begin in March?
Yes. For much of England's history, the year began on Lady Day, 25 March, until the Calendar (New Style) Act 1750. Old records dated January to 24 March often belong to the next year in modern terms.
Where the facts come from
Updated