Met Office Finds Winter Warmth Bringing More Flowers to Britain and Ireland

Flowers on New Year’s Day, counted and confirmed

On a gray New Year’s morning in Leeds, the pavements were slick and the trees bare. But in the strip of grass between a bus stop and a supermarket car park, a cluster of daisies, dandelions and white dead-nettle were in full bloom as volunteers bent to photograph and log every flower.

Scenes like this have played out across Britain and Ireland for the past decade during the New Year Plant Hunt, a citizen-science project that asks people to spend up to three hours counting wild plants in flower between Jan. 1 and 4. This year, for the first time, the United Kingdom’s national weather service has turned those lists into a precise measure of how much warmer winters are reshaping the country’s flora.

A new Met Office analysis of 10 years of New Year Plant Hunt records finds that for every 1 degree Celsius increase in average temperatures during November and December, about 2.5 additional plant species are found in bloom over the New Year period.

The work, released Jan. 2, links thousands of volunteer observations from winters 2015-16 through 2024-25 with detailed local temperature records. Scientists say it offers one of the clearest, most accessible signals yet that rising temperatures are altering the timing of the seasons for plants in Britain and Ireland.

“Our analysis underscores how rising temperatures and increasing climate extreme events are shifting the natural cycles of our plants and wildlife,” said Debbie Hemming, a climate scientist who leads the Met Office’s vegetation-climate interactions group. “It provides tangible evidence that climate change is directly influencing the world around us.”

How the New Year Plant Hunt works

The New Year Plant Hunt is organized by the Botanical Society of Britain and Ireland (BSBI), a long-established botany society whose data underpin national plant atlases and conservation assessments. The first hunt took place around 2012; by 2026, organizers described it as being in its 14th year.

The rules are simple. Between Jan. 1 and 4, participants of any skill level take a single walk of up to three hours and record every wild or naturalized plant species they can find in flower. Garden plantings are excluded, as are mosses, ferns and fungi. Observers submit their lists, locations and optional photos through a recording app or online form. Even “nil” lists, where no flowers are found, are encouraged and counted as useful data.

Participation has grown rapidly. In 2016, more than 850 people submitted lists of flowering plants, logging 612 species. By the 2024 hunt, 3,336 people had taken part, submitting more than 21,000 records and finding 629 species in bloom. The 2025 event, held from Dec. 29, 2024, to Jan. 1, 2025, drew about 3,000 volunteers, produced roughly 25,000 records and documented 647 species in flower — the third-highest total in the project’s history.

Of those 2025 records, 310 species were native to Britain and Ireland. Met Office scientists noted that botanists would traditionally expect only around 10 native species to be in flower in early January.

“That contrast is striking,” said Kevin Walker, head of science at BSBI. “The new analysis shows a very clear link between rising temperatures and impacts on our plant species. It’s also a visible signal that everyone can see in their own gardens and communities.”

Turning volunteer lists into a climate signal

To conduct the study, Met Office researchers took New Year Plant Hunt data from the 2016 to 2025 surveys and matched each list of flowering species with the average temperature for that location over the preceding November and December. Those two-month means were grouped into 1°C bands, from 3°C to 11°C.

When scientists plotted the mean number of flowering species recorded in each temperature band, a strong linear relationship appeared. On average, each additional degree of warming in late autumn and early winter corresponded to about 2.5 more species in flower during the first days of January.

The pattern reflected both geography and year-to-year variability. Lists from traditionally milder areas — southern England, coastal Ireland, low-lying urban centers — tended to fall in higher temperature bands and contained more species. Lists from colder regions, such as upland Scotland and inland areas more prone to frost, came from cooler bands and usually recorded only a handful of blooms. Warmer or colder winters in a given place also shifted results.

What’s blooming — and why

The plants recorded range from familiar lawn and pavement species to garden escapes that have become naturalized. Daisies (Bellis perennis), dandelions (Taraxacum species) and groundsel (Senecio vulgaris) are among the most frequently recorded natives and appear on top lists year after year. Common non-native species found in winter include Mexican fleabane (Erigeron karvinskianus) and white and red dead-nettles (Lamium album and L. purpureum).

Botanists sort winter flowers into several broad categories:

• Autumn stragglers: species such as yarrow and common ragwort that normally flower after midsummer but can persist into January if hard frosts are absent.
• All-year-rounders: plants like shepherd’s-purse and annual meadow-grass, adapted to flower almost continuously in disturbed habitats.
• Winter specialists: including winter heliotrope, genuinely adapted to bloom in the coldest months.
• Springtime specialists: such as primrose and lesser celandine, which sometimes appear early.

Researchers say the clearest change is how often milder late autumns allow autumn- and summer-flowering species to linger into January.

“We’ve always known that mild, frost-free late autumns lead to more flowers being recorded in the New Year,” Walker said. “What this collaboration with the Met Office does is put robust numbers to that relationship across the whole of Britain and Ireland.”

Why winter flowers matter for ecosystems

The findings land amid a broader backdrop of rapid warming. Provisional Met Office figures show that 2025 was both the United Kingdom’s warmest and sunniest year on record. Globally, agencies report that the planet is now around 1.4°C warmer than in the late 19th century, with most of that increase attributed to greenhouse gas emissions from burning fossil fuels.

Scientists say shifts in flowering time — known as phenological changes — can ripple through ecosystems. If plants bloom earlier or keep flowering into winter while pollinators, insects and birds respond differently to warming, mismatches in timing can emerge. Early blossoms might appear before bees are active, or berries may ripen too late for migratory birds that rely on them.

“Changes like this can affect the availability of food and habitats for many species,” Hemming said. “Understanding these shifts helps us anticipate risks and plan for climate adaptation.”

The winter data also highlight differences between native and non-native plants. Analyses by the botanical society suggest that roughly one-third to one-half of species recorded in flower over New Year in recent years are non-native or alien, many of them thriving in urban heat islands and disturbed ground. Warmer winters may strengthen their foothold, potentially reshaping plant communities and increasing competition for native species.

Limits of the data — and what comes next

The organizations involved stress the limits of the dataset. The New Year Plant Hunt only goes back a little over a decade, and participation has increased sharply, making it difficult to say with confidence how current winter flowering compares with several decades ago. More observers — especially in species-rich southern and urban areas — almost inevitably lead to more species being recorded.

There are also gaps in coverage. Coastal towns in southern England and Ireland are consistently well represented, often producing some of the longest species lists. Mountainous regions and remote rural areas generate fewer records, in part because fewer people live and botanize there.

Because of these factors, the Met Office analysis focuses on the relationship between temperature and flowering, rather than on simple year-by-year species totals. Sharp cold snaps can still cut down winter blooms in any given season, even as the long-term average trend is toward milder conditions.

For BSBI, the collaboration illustrates how data collected by thousands of volunteers can feed into national climate research and, eventually, into conservation planning. For the Met Office, it offers a way to communicate climate change in terms that people can see on their doorstep.

Grace Richardson, an early-career scientist at the Met Office who worked on the analysis, said the project shows “how effectively climate data and detailed plant records can be brought together to explain shifts in our environment.”

As volunteers’ 2026 records are compiled from this year’s hunt, organizers say they are already looking beyond the New Year window, exploring how similar approaches might track seasonal change across spring and autumn, and how plant data can be combined with observations of insects and birds.

For now, the sight of daisies and dandelions on a January pavement has taken on a new meaning. What once seemed like an oddity — or a small winter treat — is now mapped, quantified and tied to temperature records: a quiet but persistent signal that British and Irish winters are not what they used to be.