The occurrence regularity and formation/dissipation mechanism of fog on the Leizhou Peninsula have been statistically analyzed by using the meteorological data observed at three conventional weather stations of Zhanjiang (59 a),Leizhou (46 a) and Xuwen (42 a),which locate in the north,central and south part of the Leizhou Peninsula,respectively.The results show that the annual fog days over the three stations basically have the same variation trend in the pattern of “W”,and local maximum values increase significantly.The annual average of fog days at the three stations are 24.7 d,304 d and 210 d,respectively.Fog mainly occurs from December to next April and on the Leizhou Peninsula.The fog days is the most in March and the least in July.The frequency of night fog is up to 90% during the past decade,and fogs with short duration make up the majority,with 75% of which below the 4 hours.The synoptic situations favorable for the fog formation and development on the Leizhou Peninsula can be roughly divided into five classes:high pressure system,low pressure system,cold front,stationary front,saddle type pressure field or isobaric field.The advection fog,frontal fog and radiation fog are dominant types over Zhanjiang.The weather situations causing the dissipation of Zhanjiang fog are mainly the following:newborn cold air moving southward and surface wind speed increasing;drizzle formed due to collisioncoalescence and subsequent gravitational settling of fog droplets after fog development;fog droplets evaporating because of the increasing temperature at the near surface layer after sunrise.The statistical results of fog frequency at the three stations on Leizhou Peninsula from 2000 to 2009 show that the meteorological conditions of the biggest fogforming probability are:〖WTB1X〗T〖WTB1〗=15—25 ℃,〖WTB1X〗T〖WTB1〗〖WTB1X〗T〖WTB1〗d≤10 ℃,〖WTBZ〗Δ〖WTB1X〗p〖WTB1〗3=-35—-2 hPa and 15—25 hPa,wind direction of NNEESE and wind speed ≤5 m/s.The analysis of Lband radar sounding data shows that the temperature decreases with altitude in fog,with the fog top height at about 15 km.Relative humidity is above 92% in the fog layer,which decreases sharply from the height of 15 km until 3 km,and then remains unchanged above 3 km.The temperaturedewpoint spread is from 12 to 64 ℃,with 2—6 m/s wind speed near the ground surface.Wind direction rotates clockwisely with height,which indicates a warm advection in fog layer.