Table 1 Definition and categorization of hot, dry, and windy events (HDWs) based on different studies.

From: Temporal and spatial variations in the frequency of compound hot, dry, and windy events in the central United States

Classification

Temperature (°C)

Relative humidity (%)

Wind speed (m/s)

References

1

> 29

< 30

–

Lydolph and Williams11

2

29–37

< 30

< 7

3

29–37

< 30

≥ 7

4

≥ 38

< 30

< 7

5

≥ 38

< 30

≥ 7

–

> 35

< 30

≥ 7

Leathers and Harrington9

Slight

> 32

< 30

> 2

Wang et al.12

Severe

> 35

< 25

> 3

–

> 30

< 30

> 2

Huailiang et al.51 and Liu and Kang52

Light

≥ 32

≤ 25

≥ 3

Shi et al.53

Heavy

≥ 35

≤ 30

≥ 3