Changshu is located in the mid-latitude region of east longitude120 33 ˊ-12103 ˊ and north latitude 3133 ˊ-3150 ˊ. It belongs to subtropical humid monsoon maritime climate. Annual average temperature 16.9℃, 1 month average temperature 5.9℃, July average temperature 27.8℃, annual extreme maximum temperature 38℃, minimum temperature -5.4℃. The annual precipitation is1341.2mm, the maximum daily precipitation is 98.3mm. The annual average total sunshine hours are 2130.2h, accounting for 48% of sunshine hours. The annual maximum humidity is 95%, the minimum humidity is 20% and the relative average humidity is 77%. The constant wind direction is NE direction and SE direction with a frequency of 9%, and the secondary wind direction is ESE direction and SSE direction with a frequency of 8%. The annual frequency of wind between NNE and SSE is 57%, the strong wind is in NW direction, the maximum wind speed is 24m/s, and the annual average wind speed is 2.6m/s. The average number of typhoons affecting the local area is 2-3 times per year, and the wind direction is NE, which is generally 6-8.