Washington, D.C. Weather Forecast for September 15–21, 2025

Moving into the second half of September, Washington, D.C. has been dealing with a mix of weather patterns. Here is what to expect over the next week and into the weekend:

Monday, September 15

• High: 82°F (28°C) | Low: 62°F (17°C)
  
• Conditions: Partly cloudy with more clouds than sun.
  
• Overview: A mild beginning to the week with pleasant temperatures, good for morning strolls or some fresh air. Expect a lightly breezy afternoon.
  

Tuesday, September 16

• High: 72°F (22°C) | Low: 61°F (16°C)
  
• Conditions: Mainly cloudy with a bit of rain; breezy in the afternoon.
  
• Overview: There will be rain and breezy weather, so having an umbrella with you may be a good idea. The humidity will add to that heavy air feeling.
  

Wednesday, September 17

• High: 72°F (22°C) | Low: 62°F (17°C)
  
• Conditions: On-and-off rain and drizzle.
  
• Overview: It’s a damp day with occasional rain showers, dressed in layers to stay dry and comfortable. The roads could be slick, so drive carefully.
  

Thursday, September 18

• High: 82°F (28°C) | Low: 61°F (16°C)
  
• Conditions: Times of clouds and sun with a shower in the area; humid.
  
• Overview: Humidity is elevating and you could have a stray shower. Great day to stay indoors or visit local attractions.
  

Friday, September 19

• High: 88°F (31°C) | Low: 61°F (16°C)
  
• Conditions: Very warm with plenty of sunshine.
  
• Overview: A warm and sunny end to the work week, great for eating outside, picnics, or exploring the parks D.C. has to offer.

Weekend Outlook

Saturday, September 20

• High: 80°F (27°C) | Low: 60°F (16°C)
  
• Conditions: Mostly cloudy and not as warm.
  
• Overview: A cooler day with overcast skies; good for leisurely walks, shopping, or attending an event where bright daylight is not needed.
  

Sunday, September 21

• High: 76°F (24°C) | Low: 61°F (16°C)
  
• Conditions: Cloudy with showers.
  
• Overview: It is a cooler day with cloudy skies. Good for strolling, shopping, or enjoying an activity where it is not bright enough to need daylight.

Nature Notes

• Invasive Spotted Lanternfly: Invasive insects have been invading the D.C. region, even showing up on weather radar because of their massive movements. They don’t directly harm humans, but they can damage plants and crops.

Advice for the Coming Week

• Rain Outfit: With multiple days of rain anticipated, it is best to carry your umbrella or raincoat.
  
• Sun Safety: UV rays can be very strong when the sun is not visible, including a cloudy day. It would be best to apply sunscreen before being in the sun.
  
• Stay Hydrated: The warmest temperatures will be on Friday, so you could become dehydrated very quickly. You should always carry water.
  
• Activities Outdoors: Friday and Saturday will have the best weather for outdoor events and activities.
  

In summary, Washington, D.C., will see a number of weather changes this week, beginning with rain and cooler temperatures, then a warm and sunny day on Friday. The weekend is forecasted to be cooler and wetter, so plan activities appropriately. Whether visiting the National Mall, parks, or indoor outings, it will be important each day to check the forecast to stay comfortable and safe. With sun, clouds, and rain, this week reflects the typical transitional weather in the capital, as we move deeper into early fall.