火险指数根据风温度相对湿度以及离最近一次下雨的天数等因素而确定的森林火灾相对危险性的数值
The fire risk index is a value determining the relative risk of forest fires based on factors such as wind temperature, relative humidity, and the number of days until the last rain
以上为机器翻译结果，长、整句建议使用 人工翻译 。