Abstract:Based on the daily and hourly surface meteorological observation data of Huangshan Station from 2004 to 2016, the temporal distribution and climatic conditions of rime are analyzed. The results show that: (1) The annual average number of rime days in Huangshan is 616, with obvious differences between years. The earliest day of rime was mainly in November and the latest day was mainly in March and April. The number of consecutive rime days is often 3 to 4 days, accounting for 40% of the total number. In each year there were continuous rime days of ≥ 10 days. (2) The rime appeared mainly from October to next April, of which the number of rime days from December to next March accounted for 898%. The monthly mean number of rime days is significantly negatively correlated with the monthly mean temperature. There was a certain daily change in rime, with the highest number at 09:00, and the least at 18:00 (3) Analysis results of daily data show that suitable meteorological conditions for rime are: foggy days and daily mean temperature between -8 and 2 ℃, daily mean humidity ≥ 80%, daily mean wind speed between 2 and 9 m/s. (4) The statistics of hourly data shows that rime formation is mainly affected by air temperature. There needs a period of ≤ 0 ℃ low temperature of more than 7 hours before the formation of rime. The suitable meteorological conditions for rime are foggy and the temperature being between -6 and 1 ℃, humidity ≥ 95%, wind speed between 2 and 11 m/s, which reflect well the critical conditions of rime formation.