The average weather in Moscow in May (https://www.weather25.com/europe/rus...th&month=May): "The temperatures in Moscow in May are quite cold with temperatures between 9°C and 19°C."
From https://en.climate-data.org/asia/rus...6390/t/may-5/:
Moscow weather in May
Temperature May 13.2°C | 55.7°F
Precipitation / Rainfall May 60mm | 2.4 inches
Temperature May max. 17.7°C | 63.8°F
Temperature May min. 7.4°C | 45.4°F