Several thousands of temperature records from the Global Daily Climatology Network are analysed by means of detrended fluctuation analysis (DFA). Long-range temporal power-law correlations extending up to several years are detected for each station. Contrary to earlier claims, the correlation exponent is not universal for continental locations. Short-range correlations are also evaluated by DFA and by first order autoregressive models. The strength of short- and long-range temporal correlations seems to be coupled for large geographic areas. The spatial patterns are quite complex, simple parameter dependence such as elevation or distance from oceans cannot explain the observed variability.