China agricultural meteorological disasters wheat dry hot wind online map was derived from the National Agricultural Atlas of the People's Republic of China.

Degree: Weight, average days≧6,frequency (%) is above 50;

Degree: Secondary weight, average days 3-6, frequency (%) is 30-50;

Degree: Light, average days 1-3, frequency (%) is 10-30;

The meteorological indicators of dry and hot wheat are formulated according to suitable meteorological conditions during the grain filling period of wheat. The suitable temperature for wheat filling period is 20-22 °C. The transpiration of wheat plants increases above 25 °C, the water loss accelerates, the filling speed increases, the dry matter accumulation ends prematurely, and the grain weight decreases. If the average daily temperature is higher than 26 °C, the temperature above 14 °C at 14 o'clock will be unfavorable for grouting. The leaves die prematurely and the grout stops midway above 36 °. Appropriate soil water content should maintain 70-75% of the maximum water holding capacity in the field. If it is too dry and the relative humidity in the field is less than 30%, it will be unfavorable for grouting. The results of the study are similar, generally: the temperature is higher than 30 °C at 14 o'clock, the relative humidity in the field is less than 30%, the wind is dry and hot air when the wind is 3 m / s; the temperature is higher than 35 °C at 14 o'clock, the relative humidity in the field Below 25%, when the wind is 3 m/s, it is a heavy dry hot air process.