The pH of a neutral water is 6.5. The temperature of water

pH equal to 6.5 means $\left[{\mathrm{H}}^{+}\right]>{10}^{-7}\mathrm{M}$, i.e. there occurs more ionization of water as compared to that occurring at 25 °C. More ionization means temperature is greater than 25 °C

Water's pH level indicates how acidic or basic it is. The range is 0 to 14, with 7 acting as a neutral value. A pH of higher than 7 denotes a base, whereas one of less than 7 suggests acidity. The pH scale really measures the proportion of free hydrogen and hydroxyl ions in water.