Based on the observation data of temperature from Yibin station and other five surrounding meteorological stations in 1961-2009,temperature variation in Yibin station affected by urbanization was studied.The results showed that urban heat island effect in Yibin became more and more strong,and it had great influence on minimum temperature and little influence on maximum temperature,with obvious daily variation.In addition,heat island effect was more obvious at night than daytime,while temperature went up most greatly in summer,and next came spring,but it was weakest in winter.Compared with 1960s,the average warming rate of temperature at 02:00,08:00,14:00 and 20:00,daily average temperature,maximum temperature and minimum temperature reached 0.483 2,0.168 0,0.001 4,0.209 8,0.215 4,-0.013 4 and 0.333 2 ℃ in 40 years,respectively.Moreover,regional background had certain effect on urban climate,and the influence of urban heat island effect on various meteorological stations was distinct in different stages of urbanization process.
