Heat stress has significantly reduced grain yields in many parts of the UK

This is a direct consequence of harvest dates being a month ahead of their normal schedule. A shorter growing season, particularly for wheat, will directly impact final crop yields.

Significantly, the Agricultural and Horticultural development Board (AHDB) is confirming that Harvest 20206 is the earliest in 20 years. The organisation has just published its first Harvest Update for the 2025/26 growing season. It confirms that, for the second consecutive year, combines have entered fields significantly earlier than normal, with many farmers across the South and East of England completing harvest two to three weeks ahead of the long-term average.

Anthony Hopkins, AHDB’s Director of Cereals and Oilseeds, further explained: “Across much of the UK, combines have been rolling earlier than usual this year, with many farmers working through the night to avoid the most extreme daytime temperatures. While it's encouraging to see oilseed rape yields improving on average, cereal yields have generally been below the 10-year average so far, with some farms experiencing significant reductions. Following successive years of difficult weather and rising costs, the financial pressures are becoming increasingly acute for those businesses hardest hit.”

It is now evident that differences in rainfall and soil moisture retention have had a major influence on crop performance. Crops grown on lighter soils have generally been more affected by prolonged dry conditions than those on heavier land.

Anthony Speight, Senior Analyst for Cereals & Oilseeds at AHDB said: “Although harvest has progressed rapidly across most regions, we're seeing considerable variation in yields between farms, reflecting differences in rainfall, soil type and cropping decisions. At this stage, the emerging picture points to disappointing cereal yields in many areas, but we’ll gain a clearer understanding as harvest continues.”

The winter barley harvest is now largely complete across the UK. By the week ending July 26, an estimated 95% of the crop had been harvested, with the majority of the remaining area located in Yorkshire, Scotland and Northern Ireland. Harvest progress was particularly rapid this season, aided by favourable harvesting conditions. By the week ending 12 July, 46% of the crop had already been cut, with growers making swift progress across much of England. Yields have been highly variable this season. Based on the survey sample, the average figure is 6.8t/ha, down 2% compared to the UK five-year average. There has been a wide range in farm performance. Reported winter barley yields ranged from 3.4-11.0t/ha. This variation highlights the differing growing conditions experienced across regions and farm types during the season.

Specific weights are reported to be between 63 and 66kg/hl. Screening levels have been variable with figures of between 80-95% retained by a 2.25mm sieve. Grain nitrogen levels (for malting varieties) have also been variable: ranging from 1.7% to 2.0%. Moisture content has averaged 13.3% from farmer data, with a range of 10.4% to 16.6%. The higher moisture level was an earlier cut crop in Scotland.

The oilseed rape harvest was estimated to be 73% complete by July 26. Harvest progress has been most advanced in southern England, where the crop is largely cut, although some small areas remain to be harvested. Further north, progress has been slower, particularly in Scotland, where only 8% of the crop had been harvested by July 26. This reflects the later harvest window and differences in crop maturity across the UK. The average rape yield from the survey sample is 3.9 t/ha, up 17% compared to the UK five-year average. As with other crops this season, yields have been highly variable. Regional reported yields ranged from 2.4-4.9 t/ha.

In many cases, the highest relative yields were reported by farms that had experienced significant pest pressure in previous seasons, resulting in a lower historical baseline against which this year’s performance is measured. Overall, the results highlight the wide variation in crop performance across the sample, reflecting differences in establishment, growing conditions and local pressures during the season. Oil content has generally been reasonable ranging from 42-45% for the typical sample. While there was understandable concern about the moisture level of oilseed rape crops, this has been managed well this harvest. The average moisture is reported as 7.3%, with a range of 6.0% to 9.0%.

The oat harvest was 32% complete by July 26. Harvest progress has varied considerably across the UK, reflecting differences in crop maturity and local weather conditions. In some regions, growers have made good progress during recent dry periods, while elsewhere harvesting remains at a much earlier stage. As more of the crop is harvested over the coming weeks, a clearer picture of oat yield and quality will emerge. At this stage, regional differences in harvest progress remain more pronounced than for some of the earlier-harvested crops.

The winter wheat harvest was 54% complete by July 26. Progress has been most advanced in the South West, where 96% of the crop had been harvested according to the survey sample. Harvest conditions have generally been favourable, allowing growers to make rapid progress where crops have reached maturity. Across southern England, many farms expect to complete wheat harvesting within the coming week, provided the settled weather continues. Yields have been down so far this season. Based on the survey sample, the average figure is 6.8 t/ha, down 13% compared to the UK five-year average.

It should be noted that this benchmark is already relatively low, having been influenced by the below-average harvests recorded in 2024 and 2025. Yield performance has also been highly variable between farms. Reported yields range from 3.9t/ha to 11.5t/ha. However, only 10% of farms surveyed have reported yields above their five-year average, underlining the widespread impact of the dry conditions experienced during the growing season. While a small number of farms have achieved near-average or above-average results, the majority have reported yields below their historical performance, reflecting the challenges posed by limited rainfall from spring onwards.

Specific weights have been exceptional so far this year. For group 1 samples specific weights have ranged from 76 kg/hl to 85 kg/hl. Most samples discussed at the time of writing were 82kg/hl plus. Protein content is also high, with averages above 14% not uncommon in samples. An average of 13.5% is given although this is variable. Moisture content has ranged from 10.8% to 14.9%, averaging 12.5%.

The spring barley harvest is now underway across the UK and was estimated to be 8% complete by 26 July 2026. Harvest progress remains at an early stage, with activity concentrated in the earliest-maturing crops and regions. As more of the crop is cut over the coming weeks, a clearer picture of both yield and quality will emerge. Early indications suggest that harvest timing is generally in line with expectations, although progress varies considerably between regions depending on crop maturity and local weather conditions. The spring barley harvest is still at an early stage, and yield reports received so far have been highly variable. The average yield reported by the survey sample is currently 5.3 t/ha.

Brussels is confirming that recent heat waves have severely impacted many winter and summer crops growing across Europe. In essence, the continuing dry weather shortened the grain-filling phase of winter crops and brought forward the harvest, which has already been completed in the south and is progressing elsewhere. European Union (EU) yield forecasts for winter crops have been revised downwards by one to four percent leaving the outlook for total cereals at one percent below the five-year average. For summer crops, exceptional heat and limited rainfall across western and central Europe depleted soil moisture, constrained biomass accumulation and affected flowering.

Yield forecasts have been reduced by between six and seven percent for all spring and summer crops, most notably for grain maize and sunflowers. Hot and dry conditions are forecast to persist in Western Europe, increasing the likelihood of further yield reductions. In France, successive heat waves with record-high temperatures, combined with limited soil moisture, negatively affected the final growth stages of winter crops and the development of summer crops.

The clearest impacts observed in western regions where heat stress coincided with limited water availability. Nevertheless, generally adequate soil moisture reserves and irrigation in some areas still provide scope for crop recovery, while the south-east was less severely affected. Intense heat in Hungary and Western Romania has depleted already low soil moisture, exacerbating severe drought conditions. Maize crops have been most affected by drought conditions in parts of Italy. Here, crop growth has been suboptimal following heat stress during flowering. As a consequence, early-flowering varieties may have experienced reduced fertility. The largest impacts are expected in non-irrigated fields.

The strongest impacts have been observed in Hungary, where both winter and summer crops have been affected, while impacts in western Romania are generally less severe.

In contrast, above average rainfall may delay harvesting, reduce grain quality and favour the development and spread of diseases in parts of Northern Poland and neighbouring regions. In addition significant storms have recently been reported across Northern Italy, Slovenia, Croatia and Germany. Strong wind gusts, downbursts and hail have caused lodging and other physical damage to summer crops. Meanwhile, France is a key producer of grain maize. However, drought conditions are reducing the yield potential of 2026 crops on a daily basis. While some thunder showers are forecast to impact on Western Europe over the coming days, the prospects of real rain impacting on key maize and grain growing regions further to the East remains remote.

In Ireland the 2026 grain harvest is projected to be between 75% and 80% complete. A significant proportion of the spring barley acreage has yet to be combined. But it’s already known that Irish winter barley yields are well down on five-year average figures. The winter barley harvest is now complete in Northern Ireland. Yields have been disappointing with agronomists pointing to the wet winter and early spring as being major contributory factors in this regard. The bushel weights of harvested barley have also been disappointing.