In the present study, a beginning is made into the investigation of the effect of the urban area on the microclimate of Detroit-Windsor. Diurnal and seasonal urban-rural temperature differences were investigated using three-hourly temperature data for a 10-year period for City, Metropolitan and Windsor airports. Maximum differences were observed in early morning hours and minimum or zero differences at midday. Seasonally, maximum differences were observed in August–October and minimum differences in January–March. The differences between urban and rural atmospheric transmissivity ratios were investigated for clear winter days using a Kipp and Zonen pyranometer and a model to predict incoming solar radiation at the top of the atmosphere. Urban ratios averaged 9% less, and under calm conditions, reached 25% less than in adjacent rural areas. Data from the South Eastern Michigan Council of Governments precipitation network in the Detroit area were used in a comparison with regional seasonal precipitation patterns. Although the urban area or microscale precipitation pattern did not appear to differ on an annual basis from the regional precipitation pattern, on a seasonal basis Detroit received less precipitation than the surrounding rural areas in autumn and winter and about 20% more in summer.