Nevada gets less annual precipitation than any other U.S. state, so there's bright sun at most times of the year. Winters range from moderate (26 to 51 F/-3 to 11 C) to mild (33-58 F/1-14 C).
Most of the year is pleasant in Reno, but you should beware the midsummer during July and August. Temperatures spend several weeks above 90 F/32 C in the north, and above 100 F/37 C in the south. The hottest part of the day in summer is actually around 5 pm when the absorbed energy from the sun finally begins to release from concrete, asphalt and earth. (You'll feel the heat from above and below.)