A method of determining the temperature profile along a short length of optical fiber containing a chirped grating is presented. This provides an alternative to the known method of integrating differences between power-only reflectance spectra to recover a distributed measurement of temperature or strain within a chirped grating without the additional equipment requirements of a phase spectrum measurement. In contrast to other methods of processing the spectra of chirped gratings, the windowed cross-correlation method monitors local wavelength shifts directly, and offers immunity to spurious temperature or strain gradients arising from amplitude measurement errors.