This monitoring period covers January-April 2024, which is the land preparation period for spring wheat and summer crops, but is the critical growing period for winter wheat in the United States. Therefore, CropWatch focuses on changes in agro-climatic and agronomic indicators in the major winter wheat producing regions. In general, the main winter wheat producing areas have experienced good agro-climatic conditions and crop conditions are above the five-year average.

The United States experienced relatively warm and wet weather during this observation period. Temperatures and precipitation were 1.1°C and 7% above average respectively, while radiation was 4% below average. The favourable weather is good for winter wheat growth as it replenishes soil moisture. The potential biomass is 9% higher than the 15-year average, confirming the favourable agro-climatic conditions.

The good crop condition in the southern plains was recorded by the NDVI departure clustring and profile, where the NDVI departure is above zero, indicating above average crop condition. The national VCIx of 0.86 clearly indicates acceptable crop growth. The distribution of VCIx shows that most regions of the southern plains have VCIx above 0.8, which is a clear indication of good crop conditions, with the exception of some parts of the southern plains and northwestern regions which have VCIx values below 0.5. The overall Crop Production Index (CPI) is 1.07, indicating above average crop conditions.

In short, CropWatch assessed above average crop condtion in the United States, the winter wheat will step into harvest season, the above average crop production can be expected if no abnormal extreme climatic evernts occur.

Figure 3.42 United States crop condition, January to April 2024

(a). Phenology of United States from January to April 2024

(b). Crop condition development graph based on NDVI

(c). Time series rainfall profile

(d). Time series temperature profile

(e). Maximum VCI

(f). Spatial distribution of NDVI profiles 

(g) National CPI time series

Regional Analysis 

Winter crops are grown mainly in the Southern Plains (No. 207), Northwest (No. 206) and California (No. 201). Winter wheat growth conditions are highly spatially heterogeneous due to different agroclimatic, agronomic and irrigation infrastructure conditions.

(1) Southern Plains (207)

The southern Plains are the main winter wheat growing area in the US, centred on Kansas, Oklahoma and Texas. Overall, growing conditions in the region have been favourable. The cropped area (CALF) is 8% higher than the five-year average, the Crop production index (CPI: 1.23) is above the five-year average (0.99), and the maximum VCI stands at 0.90, which indicates a favourable growing environment. The Southern Plains region experienced wet and warm weather, with above-average rainfall and temperatures 11% and 0.9°C above the average for the same period in the last 15 years, but with radiation 3% below average. The favourable conditions resulted in biomass 5% above the 15-year average. The NDVI profile clearly shows that growth conditions for winter wheat reached a five-year maximum in April and fell back to average by the end of April. In short, CropWash has assessed the favourable crop conditions in the Southern Plains and above average crop production is expected in this region.

(h) Crop condition development graph based on NDVI

(i) Time series rainfall profile

(j) Time series temperature profile

(k) Southern Plains CPI time series

(2) Northwest (206)

The Northwest is a major winter wheat growing region in the United States, including Washington and Oregon. Overall, agroclimatic conditions were favourable, with well above average growing conditions in the region. This included rainfall and temperatures that were 3% and 0.4°C above average, radiation that was 7% below average, and relatively warm and wet weather that resulted in biomass production potential that was 5% above average. During the previous observation period, winter wheat in the region went dormant due to cold weather. However, temperatures recovered significantly to above average levels from February onwards, allowing winter wheat growth to resume. The region's region's CALF is 20% above average, the VCIx reaches 0.85, and the Crop production index (CPI) is 1.36, which is significantly higher than the five-year average (0.84). Available indicators suggest good prospects for winter wheat production in the region, provided that favourable weather conditions prevail.

(l) Crop condition development graph based on NDVI

(m) Time series rainfall profile

(n) Time series temperature pofile

(o) Northwest CPI time series

(3) California  (201)

California is the most important region for fruit and vegetable production in the USA and is also a major producer of winter wheat. According to the NDVI profile, crop condition at the end of April was close to average. During the reporting period, California had above-average rainfall (ΔRAIN +43%) and below-average temperatures and radiation (ΔTEMP -0.3°C, ΔRADPAR -12%). The significant increase in precipitation in California facilitated the growth of winter wheat, resulting in biomass production potential that was 24% above average. During the monitoring period, the region's CALF was 10% above average, the maximumVCI (VCIx) reached 0.92, and the Crop production index (CPI) reached 1.16, which is higher than the average of the past five years (0.99). California's agro-climatic conditions are ideal for winter wheat production and CropWatch predicts an above-average crop production.

(p) Crop condition development graph based on NDVI

(q) Time series rainfall profile

(r) Time series temperature profile

(s) California CPI time series

Table 3.1 United States' agroclimatic indicators by sub-national regions, current season’s values and departure from 15YA, January - April 2024

Table 3.2 United States' agronomic indicators by sub-national regions, current season’s values and departure from 5YA, January - April 2024