During this monitoring period, winter wheat reached the flowering stage in mid May. Subsequent grainfilling was completed by early July. According to the crop condition development graph, crop growth was delayed due to below-average temperatures in April and May.  NDVI values were below average during that period and then recovered to average levels in June. Agro-climatic indicators show that rainfall and temperature were below average (RAIN, -6%; TEMP, -0.7°C), radiation was above average (RADPAR, +4%) and BIOMSS was close to average （+1%).

The national average VCIx was 0.95. CALF (100%) was unchanged compared to its five-year average. The NDVI departure cluster profiles indicate that: (1) 22.4% of arable land, scattered in  East Midlands, West Midlands and east Scotland, experienced slightly above-average crop conditions. (2) 57.5% of arable land experienced slightly below-average crop conditions before June and then recovered to slightly above-average crop conditions in July, mainly in the east of England. (3) 20.0% of arable land experienced fluctuating crop conditions. The large negative departures were mostly likely due to cloud cover in the satellite images. Altogether, the conditions for wheat in the UK are assessed as average.

Regional analysis

Based on cropping systems, climatic zones, and topographic conditions, three sub-national regions can be distinguished: Central sparse crop region, Northern barley region, and Southern mixed wheat and barley region. All three sub-regions were characterized by unchanged fractions of arable land (CALF) compared to the 5-year average.

The Central sparse crop region is one of the country's major agricultural regions for crop production. Crop conditions were below  or close to the five-year average according to the NDVI development graph. This region experienced the largest rainfall deficit (RAIN -24%). Temperature was below average (TEMP -0.4°C) and radiation was above average (RADPAR +4%). Biomass was above average (BIOMSS, +3%). The VCIx was at 0.95.

In the Northern barley region, NDVI was below average or close to average. Rainfall and temerature were below average (RAIN -10%, TEMP -0.6°C) ,  and radiation was above average (RADPAR +6%). Biomass was above average (BIOMSS, +4%). The VCIx was at 0.94.

In the Southern mixed wheat and barley zone, NDVI was below average or close to average according to the crop condition graph except late July. Rainfall and temperature were significantly below average (RAIN -16%, TEMP -1.0°C),  and radiation was above average (RADPAR +4%). Below-average temerature and rainfall resulted in below-average biomass (BIOMSS, -1%). The VCIx was at 0.95.

Figure 3.17 United Kingdom crop condition, April‐July 2021

(a). Phenology of major crops

(b) Crop condition development graph based on NDVI   (c) Maximum VCI 

(d) Spatial NDVI patterns compared to 5YA  (e) NDVI profiles 

(f) Time series rainfall profile (left) and temperature profile (right) 

(g) Crop condition development graph based on NDVI (Northern Barley region (left) and Central sparse crop region  (right))

(h) Crop condition development graph based on NDVI (Southern mixed wheat and Barley zone)

Table 3.25 United Kingdom's agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, April ‐July 2021

Table 3.26 United Kingdom's  agronomic indicators by sub-national regions, current season's values and departures from 5YA, April ‐July 2021