Weather Conditions and Attire
May is a great month to visit Washington, D.C. The weather can be a mix of hot, humid temperatures, as well as colder, rainy days. So bring a good variety of clothes, a light jacket and an umbrella.
Average temperatures in May range from a high of 75˚F (24˚C) during the day and a low of 56˚F (13˚C) at night.
The temperature of the meeting rooms may not be within your comfort level, so you are encouraged to wear layered outer clothing (jackets or sweaters). The attire of the meeting is business or business casual.