30YearWeather
Washington DC in September
Washington DC weather in September - United States
😊Warm & Pleasant

Washington DC Weather in September

Plan your September trip to Washington DC, United States. Based on 30 years of NASA data, expect temperatures of 26°C (high) to 17°C (low), with 27% rain probability and 8 hours of daily sunshine. Pack rain gear for around 20 rainy days.

Avg High
26°C

Hottest around day 4

Avg Low
17°C

Coolest around day 30

Rainy Days
20days

27% avg rain chance

Sunshine
8hrs/day

Autumn season

Washington DC September Weather Calendar

Click any day to see detailed weather information

Essential Travel Info for Washington DC

Currency

USD

$ United States dollar

Language

English

Driving

Right side

Connect

The D.C. government operates a network o...

Safety

Moderate Safety

GPI: 2.44

Travel Intelligence

Exclusive flight analytics & health data for Washington DC

Smart Flight Estimator

Airport-to-Airport Logistics

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Add your home location in settings to see airport details.

Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Well Connected
71/ 100
Traffic Index

Popular destination

Peak Daily Arrivals

0

slots per day

Peak

Jun

Low

Jan

Monthly Traffic Distribution

321
Jan
333
Feb
366
Mar
383
Apr
417
May
470
Jun
453
Jul
457
Aug
447
Sep
421
Oct
362
Nov
397
Dec
Traffic Level
Low Season

Key Connections

Atlanta Hartsfield Jackson (ATL)
Denver (DEN)
Charlotte Douglas (CLT)
San Francisco (SFO)
Teterboro (TEB)

Health & Safety Advisory

CDC travel health recommendations

No Requirements

No Special Vaccinations Required

Standard travel precautions apply

Source: CDC Travelers' Health

View Complete Health Guide

Is September a Good Time to Visit Washington DC?

👍Solid choice for most travelers
Short Answer

September is Washington DC's peak season for good reason: 26°C temperatures and 27% rain probability. But expect crowds (95% of annual maximum) and premium prices.

Decision Factors

Peak tourist season

95% of annual peak - expect crowds and peak prices

Ideal temperature range

26°C - perfect for sightseeing and outdoor activities

Plenty of sunshine

8.8h of sunshine daily

Exceptional dining scene

112 Michelin-listed restaurants

Good For

  • 👨‍👩‍👧‍👦
    Families with children

    Comfortable 26°C temperatures and low 27% rain risk

  • 👴
    Elderly travelers

    Comfortable 26°C temperature range with manageable humidity

  • 🏛️
    Cultural tourists

    Comfortable conditions for exploring museums and sites

  • 💼
    Business travelers

    Climate-controlled meetings unaffected by weather

  • 🌡️
    Heat-sensitive visitors

    Manageable 26°C without oppressive humidity

Who Should Avoid

  • 💰
    Budget travelers

    Peak season means premium prices everywhere

900 observations30-year historical data
Confidence: 95%

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Washington DC in September averages 26°C with 27% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: Washington DC in September

What are the temperatures in Washington DC in September?

Daytime highs average 26°C, nights drop to 17°C. Temperatures remain fairly consistent.

How many rainy days in Washington DC in September?

Expect around 20 days with measurable rainfall. Rain is unlikely to disrupt plans.

What to wear in Washington DC in September?

Comfortable casual wear with a light jacket for evenings.

Is September peak season in Washington DC?

This is shoulder season—moderate prices and manageable crowds.