Night Temperature. 1  The highest day temperature in May 2017 was 89°F. 2  The average sea surface temperature in May 2017 for Kyoto was 62.9°F. 3  Most of the days in May are sunny but you can also expect cloudy and gloomy days. 4  Precipitation total in May for Kyoto is 4.2 in. 5  The average wind speed in May is 4.9 mph.