Both the Wilkinson Microwave Anisotropy Probe(WMAP) and Planck missions have reported an extremely cold spot(CS) centered at Galactic coordinate(l = 209?, b =-57?) in the cosmic microwave background map. We study the local non-Gaussianity of the CS by defining local Minkowski functionals. We find that the third Minkowski functional ν2is quite sensitive to the non-Gaussianity caused by the CS. Compared with random Gaussian simulations, the WMAP CS deviates from Gaussianity at more than a 99% confidence level with a scale of R ～ 10?. Meanwhile,we find that cosmic texture provides an excellent explanation for these anomalies related to the WMAP CS, which could be further tested by future polarization data.
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