Temperature during the hottest quarter 0.925401 Compound topographic index (relative wetness) 1.02977 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.04832 Elevation 1.15872 Nitrogen content of soil 1.17624 Precipitation during the driest quarter 1.21751 Carbon content of soil 1.28812 Precipitation during the wettest quarter 1.30304 Precipitation during the coldest quarter 1.44451 Precipitation during the hottest quarter 1.49203 Ratio of precipitation to potential evapotranspiration 1.58281 Solar interception 1.87202 Available water holding capacity of soil 1.94918 Bulk density of soil 2.44949 Sum of monthly Tavg where Tavg >=5 deg C 2.63214 Day/night diurnal temperature difference 2.79214 Temperature during the coldest quarter 5.32674