Is climate change good or bad for UK bees overall?

The net effect is negative for most UK bee species. Some low-elevation, warm-adapted species are expanding, but upland specialists are losing suitable habitat, phenological mismatches are increasing, and drought periods are reducing summer nectar availability.

What is phenological mismatch in the context of bees?

Phenological mismatch occurs when bee emergence and flower flowering dates shift at different rates due to warming, creating timing gaps. Bees may emerge before key flowers open, or flowers may peak before bees are active enough to visit at high frequency.

Which UK bee species are most threatened by climate change?

Upland and northern species like the mountain bumblebee (Bombus monticola) are most at risk as warming temperatures push their suitable habitat to higher elevations and ultimately to no remaining suitable UK terrain.

Are UK honey yields affected by climate change?

Yes. Dry summers reduce nectar flow in July and August, a period already prone to honey bee forage gaps in southern England. Warmer winters reduce the broodless period that beekeepers use for oxalic acid Varroa treatment, complicating pest management.

What does the University of Reading research show about UK bees and climate?

University of Reading researchers including Professor Simon Potts have studied the effects of land use and climate on UK pollinators. Their work confirms that combined pressures of habitat loss, climate variability, and pesticide exposure reduce pollinator diversity more than any single factor alone.

How does warmer weather affect Varroa mite populations?

Warmer winters mean honeybee colonies may continue rearing brood later in the year and resume earlier in spring, extending the period when Varroa can reproduce in capped brood. This complicates the timing of oxalic acid treatment, which is most effective in the broodless period.

Are any UK bee species moving northward due to warming?

Yes. The ivy bee (Colletes hederae) has expanded from southern England northward since the 1990s, now recorded across most of England and into Wales. Several solitary bee species previously confined to the south are establishing populations in the Midlands and Yorkshire.

What do DEFRA's climate projections mean for UK pollinators?

DEFRA's 25-Year Environment Plan and UK climate projections both acknowledge that warmer, drier summers will reduce summer nectar flow, and that the combination of habitat loss and climate pressure requires active habitat restoration to maintain pollinator populations.

Honey guide

Climate Change and Britain's Bee Populations

How rising temperatures, shifting seasons, drought, and phenological mismatch are reshaping UK bee populations — and what beekeepers can do about it.

By Honey Honey Honey · Published 3 June 2026

How is climate change already affecting UK bee species?

Climate change is reshaping UK bee distributions, emergence timing, and colony dynamics through temperature increase, altered precipitation patterns, and more frequent extreme weather events. Average UK temperatures have risen approximately 1°C since pre-industrial baselines, with greater warming in summer maxima and a measurable reduction in frost days per year. These changes are not uniform — upland areas are warming faster in some seasons, and southern England has seen sharper increases in summer temperature extremes.

The effects on bees are already measurable. Range expansions for warm-adapted southern species are documented. The ivy bee (Colletes hederae), first recorded in the UK in Dorset in 2001, has spread northward at approximately 10km per year and is now present across England into Wales and the southern edge of Scotland. Several mining bee species (Andrena) previously confined to southern counties are now recorded regularly in the Midlands.

At the other end of the spectrum, upland and cold-adapted species face range compression. The mountain bumblebee (Bombus monticola) is restricted to upland habitats above roughly 400 metres in England and Wales. As temperatures warm, the cool conditions it requires shift to higher elevations. UK upland areas have limited total area above 400m, and that area decreases above 600m and 800m. The species has no northward expansion available in England — Scotland offers the most viable refuge.

The UK Centre for Ecology and Hydrology's National Pollinator Monitoring Scheme has been recording wild bee species distributions since 2017, providing the data needed to track these changes over time. Historical records from county natural history societies and the Bees, Wasps and Ants Recording Society (BWARS) provide earlier baselines for comparison. Taken together, the data shows a net shift toward warm-adapted species and a retreat of specialists.

Are warmer UK temperatures helping or harming honeybees?

Warmer temperatures have mixed effects on honeybee colonies. The direct benefits include earlier colony build-up in spring — warmer March and April temperatures allow queens to lay earlier and colonies to expand worker populations faster, giving more foragers available when oilseed rape flowers. Extended warm autumns give colonies more time to build winter stores, and milder winters mean the cluster consumes fewer stores during the cold period.

The drawbacks are significant and partly counterintuitive. Warmer winters with shorter cold periods mean colonies retain brood later into autumn and resume brood rearing earlier in spring, reducing or eliminating the broodless window. This is problematic for Varroa management: oxalic acid treatment — the most effective approved treatment — works by contacting adult bees during a broodless period when no mites are hidden in capped cells. Shorter or absent broodless periods mean mite treatment is less thorough.

Summer heat poses a different problem. UK colonies handle temperatures up to around 35°C internally without major difficulty, cooling the hive by water evaporation. But sustained heat above 38°C outdoors, increasingly common in southern England during July and August, reduces forager activity, stresses adult bees, and in extreme cases causes comb to melt and wax foundations to buckle. The 40°C days recorded in England in July 2022 were outside the range UK bees had historically experienced.

Milder, wetter winters — rather than cold winters — are actually harder for colonies than consistent cold. A colony in a tight winter cluster conserves energy well. Repeated mild periods through the winter cause the cluster to break, bees to become active and consume stores, and the colony to enter spring depleted. UK winters in the 2010s and 2020s have tended toward milder and more variable rather than simply warmer in a steady way, which creates exactly this difficult pattern.

What is phenological mismatch, and how does it threaten UK bees?

Phenological mismatch is a timing disruption that occurs when two interdependent species — in this case bees and flowering plants — respond to temperature changes at different rates, creating a gap where they previously overlapped. Bees and flowers have co-evolved over millions of years so that peak bee activity and peak flower availability coincide. Climate change is beginning to disrupt that alignment.

In the UK, spring flowering dates for many tree and shrub species have advanced significantly over the past four decades. Cherry and blackthorn blossom, traditionally mid-April, is now frequently appearing in late March in southern England. Hawthorn, which UK beekeepers consider an important early-season nectar source, has also advanced. These changes are well-documented in the Woodland Trust's Nature's Calendar records, which have long-term data series going back decades.

Bee emergence dates are also advancing, but not necessarily at the same rate as flowering. Bumblebee queen emergence from hibernation depends on accumulated heat units (degree-days above a threshold temperature). This system is reliable but calibrated to different cues than flowering, meaning the two may not advance together proportionally. When cherry blossom peaks 10 days earlier but bumblebee queen emergence advances only 5 days, there is a net mismatch of 5 days during which flowers produce nectar that bees do not fully collect.

For specialist relationships — where a bee species preferentially visits a particular plant genus — mismatch is particularly damaging. The spring mining bee Andrena fulva, common in UK gardens, specialises in early fruit tree blossom and willow. If its emergence consistently falls a week after peak pollen availability in warm springs, its reproductive success declines. NERC-funded research at the University of Leeds has modelled UK pollinator-plant networks and found that phenological mismatch is increasing in frequency and magnitude with observed temperature trends.

How is climate change affecting the range of UK wild bee species?

Climate change is acting as a range-shifting driver for UK bee species, generally moving suitable habitat northward and upward in elevation. A 2019 study in Nature Climate Change, using BWARS distribution records, found that UK bumblebee species' northern range limits had shifted measurably northward between the 1970s and the 2010s, while southern limits had not retreated equivalently — suggesting range expansions for warm-adapted species rather than simple latitudinal shifts.

Species showing northward expansion include: the early bumblebee (Bombus pratorum), now commonly recorded in the Scottish Highlands; the buff-tailed bumblebee (Bombus terrestris), increasingly active year-round in southern England and extending into urban Scotland; and multiple Andrena species previously absent from northern England now establishing regular records in Yorkshire and beyond.

Species showing range contractions are predominantly upland and northern specialists. The great yellow bumblebee (Bombus distinguendus), once distributed across mainland Britain, is now confined to the far north of Scotland, Orkney, and parts of Wales. Its decline is attributed to combined habitat loss (decline of flower-rich machair and coastal grasslands) and climate pressure. The short-haired bumblebee (Bombus subterraneus) became regionally extinct in England and was reintroduced from Swedish populations in 2012 — its original decline was habitat-driven but climate makes re-establishment more difficult in its former range.

The Bumblebee Conservation Trust's monitoring work has produced range maps showing these contractions clearly. For solitary bees, equivalent distribution trend data is patchier, but the National Pollinator Monitoring Scheme is building comparable series. The overall picture across both groups is consistent: generalist species tolerating a wide range of conditions are doing relatively well; habitat-specialist and climate-specialist species are losing ground.

What is the impact of UK droughts on nectar availability?

UK summer droughts reduce nectar production in flowering plants by triggering stomatal closure and redirecting plant resources away from nectar secretion. Plants produce nectar partly as an advertisement to pollinators, but under water stress they cut production to conserve resources. Bees visiting flowers that appear fully open may find them empty or producing far less nectar than the same flowers in well-watered conditions.

This effect was documented clearly in the 2018 UK drought, one of the driest summers on record for parts of England. Beekeepers across East Anglia and the South East reported near-zero honey yields in July and August despite strong colonies and apparently good floral cover. The flowers were present but the nectar was not — a deceptive landscape where bees expended energy foraging for reduced returns. Some beekeepers supplemented colonies with sugar syrup to prevent starvation during August.

Clover — normally a major summer honey source in the UK — shows particularly strong nectar reduction under drought. White clover stops nectar production rapidly when soil moisture falls below field capacity. Knapweed, another key summer wild forage plant, also reduces nectar under heat stress. Phacelia and borage are relatively drought-tolerant and maintain nectar production better in dry conditions, which partly explains their high value in recent UK summers.

The NERC-funded BeeWalk long-term monitoring programme, coordinated by the Bumblebee Conservation Trust, has detected year-to-year variation in bumblebee abundance correlating with summer rainfall. Wet Julys and Augusts, which maintain soil moisture and nectar flow, correlate with better bumblebee counts in subsequent surveys. The mechanism likely operates through colony nutrition — well-fed late-summer colonies produce more queens and workers for the following year's population.

How does unpredictable UK weather affect honey yields?

Honey yields in the UK vary considerably year to year, and unpredictable weather is the dominant variable beyond beekeeper management quality. A cold wet May during oilseed rape flowering — when bees cannot fly and the nectar flow is in progress — can eliminate the spring honey crop entirely. A warm dry June and July can produce exceptional white clover and wildflower honey. The variability between seasons in a single apiary can exceed 100% of the average yield.

The UK's maritime climate has historically produced predictable seasonal patterns — wet Atlantic weather interrupted by warm settled spells. Climate change is shifting this toward more extreme events with less reliable timing. The 2012 season, one of the worst on record for UK beekeepers, combined a cold late spring with the wettest summer in a century in many areas. Many beekeepers harvested no surplus honey at all. The 2018 season, in contrast, produced exceptional yields in some areas before the summer drought cut off the late flows.

Beekeepers manage unpredictability partly through good feeding practice: ensuring colonies have adequate stores for short and long periods without foraging, rather than relying on continuous natural forage. Emergency feeding with sugar syrup or fondant maintains colony health through gaps. Commercial beekeepers with many sites spread geographical risk, as weather systems rarely affect all sites simultaneously.

Met Office seasonal forecasting accuracy over 3-month periods has improved but remains insufficient for operational beekeeping planning. The shift toward longer, more confident heatwave warnings has given beekeepers more notice to ensure colonies have adequate water access during extreme heat events — one management adaptation that has improved in the climate change era.

Are any UK bee species already showing population shifts due to climate change?

Several UK bee species show documented population shifts attributable at least partly to climate change, distinct from habitat loss effects. The ivy bee (Colletes hederae) is the clearest example of northward range expansion. Since its first UK record in 1993, it has spread across southern England, into the Midlands, and into Wales. It is now recorded as far north as the Yorkshire Dales and central Scotland. Its range limit appears to be advancing at a pace consistent with observed temperature changes rather than habitat availability alone.

The tree bumblebee (Bombus hypnorum) arrived in the UK from continental Europe in 2001 — the first new UK bumblebee species in recorded history. It has since spread to every county in England, Wales, and southern Scotland. While natural dispersal and possible assisted introduction are both possible explanations, the timing coincides with the period of measurable UK warming. The species is common in northern France and the Low Countries; its colonisation of the UK south coast fits a pattern of climate-driven range expansion seen in other insects.

The ruderal bumblebee (Bombus ruderatus) and brown-banded carder bee (Bombus humilis) both declined severely through the 20th century, primarily from habitat loss. Climate change creates an additional pressure on these species' southern UK populations — they are at the warmer edge of their tolerance and their remaining strongholds in the South and Southeast may become less suitable as temperatures continue rising.

Monitoring data from the Bumblebee Conservation Trust's BeeWalk transect scheme, running since 2008, shows clear year-to-year population fluctuations for most species, with weather and habitat condition as the main explanatory variables. Disentangling climate effects from habitat and pesticide effects requires long data series; the UK now has enough years of structured monitoring to begin seeing trend signals through the noise of annual variation.

What do UK climate projections mean for bee populations by 2050?

UK climate projections from the Met Office UKCP18 scenarios project a 2-3°C increase in average summer temperatures across England and Wales by 2050 relative to the 1981-2000 baseline, with significant increases in drought frequency. Hot summers like 2018 and 2022, currently considered unusual, are projected to become typical by mid-century under moderate emissions scenarios. Winter temperatures are projected to increase and cold snaps to become shorter and rarer.

For bee populations, these projections translate to: continued northward and upward range shifts for warm-adapted species; further range compression for upland and northern specialists with no available refugia; increased frequency and severity of summer nectar droughts; shorter broodless periods for honeybees complicating Varroa management; and more frequent extreme heat events affecting adult bee survival and hive integrity.

The Bumblebee Conservation Trust's climate modelling, published in collaboration with the University of York, projected that several UK bumblebee species could lose more than 50% of their current UK range by 2050 under high emissions scenarios. Low emissions scenarios reduced but did not eliminate these losses. The mountain bumblebee (Bombus monticola) faces the most severe projected range loss in England and Wales, potentially confined to a few upland areas in Snowdonia and the northern Pennines.

DEFRA's National Pollinator Strategy acknowledges climate change as a major driver of future pollinator change but the strategy's targets are framed around habitat area and quality rather than climate-specific interventions. Natural England's agri-environment schemes include climate adaptation elements, but the scale of habitat restoration needed to provide climate refugia for declining bee species significantly exceeds current scheme ambition and budget.

What can beekeepers do to help their colonies adapt to climate change?

Effective Varroa management is the most important action beekeepers can take in the context of climate change. Warmer winters reducing the broodless period mean beekeepers must monitor more carefully and potentially apply treatment at non-traditional times. The Varroa decision-support tools on DEFRA's BeeBase, including infestation calculators and treatment timing guides, are calibrated to UK conditions and should be consulted at least seasonally.

Colony nutrition management matters more as droughts become more frequent. Providing supplementary feeding during June-August dearth periods, particularly in drier eastern England, prevents nutritional stress that amplifies Varroa and disease effects. Planting or encouraging forage plants that are drought-tolerant — borage, phacelia, echium — near apiaries provides nutritional insurance in dry seasons.

Water provision has become standard advice for summer beekeeping but is more critical in hot summers. Colonies use large quantities of water for evaporative cooling. A source within 200m of the hive reduces forager diversion to water-seeking at the expense of nectar collection and reduces the risk of bees congregating at swimming pools, water butts, and garden ponds and becoming a nuisance to neighbours.

Genetic diversity within apiaries provides resilience to novel disease pressures and environmental stresses. Beekeepers with locally adapted queen lines — particularly those showing hygienic behaviour and Varroa-sensitive hygiene (VSH) traits — have colonies better positioned to cope with multiple concurrent stressors. The BBKA's regional breeding programmes support access to hygienic-trait queens. Avoiding over-reliance on a single queen line or imported queen source maintains the adaptive capacity of local honeybee populations as conditions change.

Frequently asked questions

Is climate change good or bad for UK bees overall?: The net effect is negative for most UK bee species. Some low-elevation, warm-adapted species are expanding, but upland specialists are losing suitable habitat, phenological mismatches are increasing, and drought periods are reducing summer nectar availability.
What is phenological mismatch in the context of bees?: Phenological mismatch occurs when bee emergence and flower flowering dates shift at different rates due to warming, creating timing gaps. Bees may emerge before key flowers open, or flowers may peak before bees are active enough to visit at high frequency.
Which UK bee species are most threatened by climate change?: Upland and northern species like the mountain bumblebee (Bombus monticola) are most at risk as warming temperatures push their suitable habitat to higher elevations and ultimately to no remaining suitable UK terrain.
Are UK honey yields affected by climate change?: Yes. Dry summers reduce nectar flow in July and August, a period already prone to honey bee forage gaps in southern England. Warmer winters reduce the broodless period that beekeepers use for oxalic acid Varroa treatment, complicating pest management.
What does the University of Reading research show about UK bees and climate?: University of Reading researchers including Professor Simon Potts have studied the effects of land use and climate on UK pollinators. Their work confirms that combined pressures of habitat loss, climate variability, and pesticide exposure reduce pollinator diversity more than any single factor alone.
How does warmer weather affect Varroa mite populations?: Warmer winters mean honeybee colonies may continue rearing brood later in the year and resume earlier in spring, extending the period when Varroa can reproduce in capped brood. This complicates the timing of oxalic acid treatment, which is most effective in the broodless period.
Are any UK bee species moving northward due to warming?: Yes. The ivy bee (Colletes hederae) has expanded from southern England northward since the 1990s, now recorded across most of England and into Wales. Several solitary bee species previously confined to the south are establishing populations in the Midlands and Yorkshire.
What do DEFRA's climate projections mean for UK pollinators?: DEFRA's 25-Year Environment Plan and UK climate projections both acknowledge that warmer, drier summers will reduce summer nectar flow, and that the combination of habitat loss and climate pressure requires active habitat restoration to maintain pollinator populations.