Urbanization effects on temperature: 1826–1850

Mean, minimum and maximum monthly temperatures for 58 stations in New York State covering the period 1826–1850 are used to estimate a random effects panel regression. Controlling for latitude, elevation and seasonality, a statistically significant positive effect of population on minimum temperature is detected. At the mean population of 8500, the estimated effect is 0.19 °F (0.105 °C), which is consistent with published estimates for later periods. Mean and maximum temperature effects are +0.06 °F (+0.033 °C) and − 0.05 °F (−0.027 °C), respectively, but are not statistically significant. Microclimate and other unmeasured weather station heterogeneity is captured as a random ‘effects’ distribution variable, a novel treatment. Heat island effects appear to exist at very low levels of population when energy was based on animals and water power, perhaps due to loss of greenspace. Based on these results urbanization could contribute as much as 27.5 % to 41 % of the centennial temperature rise in New York.