Copenhagen in September

In September, Copenhagen averages 18°C (64°F) during the day and 11°C (52°F) at night, with around 12 days of rain (65 mm total).

High season

Conditions are comfortable for sightseeing without being sweltering. Plan for unsettled weather and bring rain gear.

September offers comfortable temperatures in Copenhagen, with some rain to plan around.

18°C
Avg high
11°C
Avg low
12
Rain days
65 mm
Rainfall

How September compares to the rest of the year in Copenhagen

4th
warmest month of the 12
3rd
wettest month of the 12
10%
of yearly rainfall falls in September
12 h 48 min
daylight on the 15th

September is in the middle of the year for warmth in Copenhagen (4th of 12) and one of the wettest months (3rd of 12). Daytime temperature runs 6°C above the annual average (12°C). September runs 4°C cooler than August (22°C) and cools 5°C in October (13°C).

September sunrise & sunset in Copenhagen

🌅
Sunrise (15th)
6:41 AM
🌇
Sunset (15th)
7:29 PM
Day length
12 h 48 min

Times shown for Copenhagen local time (Europe/Copenhagen), calculated for the 15th of September. They shift by a few minutes day to day across the month.

Photography light in Copenhagen — September

Golden-hour and blue-hour windows for the 15th of September, in Copenhagen's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
5:41 AM – 6:21 AM
🌄 Golden hour (AM)
6:21 AM – 7:21 AM
🌇 Golden hour (PM)
6:49 PM – 7:49 PM
🌆 Blue hour (PM)
7:49 PM – 8:29 PM
Milky Way galactic core
Poor
Core barely rises (or hasn't yet returned for the season). Consider a different month.
Aurora visibility
Fair
Aurora is possible from Copenhagen but requires a strong geomagnetic event (Kp 5+) plus clear skies — chase nights, don't count on them.

📅 When to book — Copenhagen in September

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (High season) and Copenhagen's popularity.

✈ Flights — lead time
2-3 months
Prices are above off-season but not the absolute peak. Tuesday/Wednesday departures are usually cheaper than weekend ones.
🏨 Lodging — lead time
2-3 months
Wide selection still available at this lead time. Premium properties book first; consider 'last-minute deal' availability at 2-week mark if your dates are flexible.

Crowds & pricing — September in Copenhagen

High season

This is a busy month in Copenhagen — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.

Why this tier: excellent tourism weather

Sun & mosquito risk — September in Copenhagen

☀️ UV Index (noon, 15th)
6.6
High
Cover up and apply SPF 30+ for any outdoor activity longer than 30 minutes.
🦟 Mosquito risk
●●○○○
Low
Mosquitoes present but manageable. Pack repellent (DEET 10-20%) for evenings near water.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in Copenhagen — September

18°C (64°F)
cool
swimmable but bracing — wetsuit helps for long sessions

Across the year Copenhagen's sea swings from 2.7°C (February) to 18.9°C (August) — September sits at 18°C.

Copenhagen in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 3°C / 37°F -1°C / 30°F 50 mm 12 4
February 3°C / 37°F -2°C / 28°F 35 mm 9 4
March 6°C / 43°F 0°C / 32°F 35 mm 9 2
April 11°C / 52°F 3°C / 37°F 40 mm 9 0
May 16°C / 61°F 8°C / 46°F 45 mm 9 0
June 19°C / 66°F 11°C / 52°F 60 mm 10 0
July 22°C / 72°F 14°C / 57°F 65 mm 10 0
August 22°C / 72°F 14°C / 57°F 65 mm 10 0
September 18°C / 64°F 11°C / 52°F 65 mm 12 0
October 13°C / 55°F 7°C / 45°F 60 mm 12 0
November 7°C / 45°F 3°C / 37°F 60 mm 13 1
December 4°C / 39°F 0°C / 32°F 55 mm 12 3

Other cities with similar September weather

🌍 See the full ranked list of climate twins for Copenhagen in September →

Frequently asked questions

How hot is Copenhagen in September?

In September, Copenhagen averages a high of 18°C (64°F) and a low of 11°C (52°F) — generally mild and pleasant.

Does it rain a lot in Copenhagen in September?

September can be fairly wet in Copenhagen, with about 12 rainy days on average.

Is September a good time to visit Copenhagen?

September is mild and pleasant. It suits travelers who are comfortable with mild and pleasant weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Copenhagen in September?

Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full September packing list for Copenhagen for a complete, climate-based checklist.

Open Copenhagen on the interactive map

Check the live 10-day forecast and sunrise/sunset.