We compute photoionization models for the giant extragalactic H II region NGC 2363, and compare them with optical observational data. We show that models computed with the observed metallicity of the cluster (Z=0.10 Zodot) do not reproduce the observed features of the spectrum, and that the disagreement can be overcome by allowing for spatial temperature fluctuations in the nebula. Accordingly, we show that the metallicity of NGC 2363 has been underestimated, and that a value of Z~=0.25 Zodot is in better agreement with the observational data than the usually adopted value Z~=0.10 Zodot.