Early September 1 September
74°F
Typical afternoon high
29% historical wet-day frequency
Germany · City
Is September a good time?
September averages 70°F afternoons, with about 7 rain days. Later September is typically cooler.
Historical Köln regional averages, not a forecast or a measure of queues. Overnight demand compares average stays per day. Covers Cologne, Bonn and Aachen; conditions vary within the region.
What matters most?
Weather 50% · Crowds 30% · Cost 20%
#4 of 12 months here · Balanced mix
Overall combines weather, overnight demand and cost. It does not include sea temperature.
Plan your September
Afternoons around 70°F (21°C): T-shirt weather; nights around 51°F (10°C): a sweater and a light jacket. About 13 hours of daylight. About 7 rain days in a typical September.
The sun rises about 07:06 and sets about 19:50 (local time, mid-month). Mornings start around 51°F (10°C); afternoons reach about 70°F (21°C). Expect rain on about 7 days in a typical September.
Early, middle or late?
Early September is typically warmer. The afternoon high averages 74°F on the 1st, versus 65°F on the 30th. Historical wet-day frequency rises from 29% to 34% between those dates.
74°F
Typical afternoon high
29% historical wet-day frequency
70°F
Typical afternoon high
32% historical wet-day frequency
65°F
Typical afternoon high
34% historical wet-day frequency
Historical daily averages from 2011–2025, smoothed over two weeks. A seasonal pattern, not a forecast. This does not establish which week has the lowest prices or fewest visitors.
Weather shows historical patterns, not a forecast. Holidays and events use the dates shown for 2027.
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
| 174° | 274° | 374° | 473° | 573° | ||
| 673° | 772° | 872° | 972° | 1072° | 1172° | 1271° |
| 1371° | 1471° | 1570° | 1670° | 1769° | 1869° | 1969° |
| 2068° | 2168° | 2268° | 2367° | 2467° | 2567° | 2666° |
| 2766° | 2866° | 2965° | 3065° |
Afternoon high rain likely (25%+) local school holidays public holiday event
School-holiday dates for September 2027 aren't available in our data yet. A day without a school marker doesn't mean schools are open.
Afternoons cool from about 73°F (23°C) in the first week to 66°F (19°C) in the last. The chance of a wet day runs 27–34%.
Visitor season
Steady all year. September averages 93% of August's overnight stays per day. Overnight demand varies little across the year.
Overnight stays across Köln do not measure queues, day visitors or congestion at individual sights.
Hotel price season
About usual. Estimated from national hotel prices and local visitor demand; no measured regional room rate is available.
Fewer overnight stays do not automatically mean cheaper rooms. Check actual quotes for your trip.
Year-to-year variation
In the 15 years from 2011 to 2025, the month's afternoons averaged between 65°F (18°C) and 76°F (24°C); in 9 of them they were within 3°F (1.5°C) of the typical 70°F (21°C). Rain days ranged from 3 to 13; half the years had 6–12.
Rain days in each September
| Year | Afternoon high | Rain days |
|---|---|---|
| 2011 | 70°F | 7 |
| 2012 | 68°F | 7 |
| 2013 | 67°F | 12 |
| 2014 | 69°F | 7 |
| 2015 | 65°F | 10 |
| 2016 | 76°F | 3 |
| 2017 | 66°F | 12 |
| 2018 | 72°F | 6 |
| 2019 | 69°F | 9 |
| 2020 | 73°F | 6 |
| 2021 | 71°F | 6 |
| 2022 | 68°F | 13 |
| 2023 | 75°F | 7 |
| 2024 | 70°F | 12 |
| 2025 | 68°F | 11 |
Checked against 10 local weather stations. How we check
Compare dates
| Typical conditions | Aug | Sep | Oct |
|---|---|---|---|
| Afternoons | 77°F | 70°F | 61°F |
| Rain days | 9 | 7 | 12 |
| Overnight demand | 100% | 93% | 92% |
August: Warmer afternoons and more rain days than September. August guide →
October: Cooler afternoons and more rain days than September. October guide →
Overnight demand measures accommodation stays, not queues.
Yellow marks the top three months on the Balanced mix. September stays as your reference.
Hotel stays vary little through the year. No other scored month has a Weather score at least 1.0 point higher than September.
Your comparison
Overnight stays vary little through the year.
National hotel prices and local visitor demand suggest about usual. No measured regional room rate is available.
Read the August guide →| Typical conditions | September | August |
|---|---|---|
| Afternoons | 70°F | 77°F |
| Nights | 51°F | 56°F |
| Rain days | 7 | 9 |
| Visitor season | Steady all year | Steady all year |
| Overall / 10 | 7.4 | 7.6 |
| Month rank | #4 | #1 |
| Month | Overall | Rank | High | Low | Rain days | Weather | Visitor season |
|---|---|---|---|---|---|---|---|
| January | 4.9 | #12 | 43°F | 32°F | 16 | 3.9 | Steady all year |
| February | 5.6 | #10 | 47°F | 33°F | 11 | 4.7 | Steady all year |
| March | 6.1 | #8 | 53°F | 36°F | 11 | 5.9 | Steady all year |
| April | 6.8 | #6 | 60°F | 40°F | 8 | 7.2 | Steady all year |
| May | 7.2 | #5 | 67°F | 47°F | 10 | 8.1 | Steady all year |
| June | 7.5 | #3 | 74°F | 54°F | 9 | 8.7 | Steady all year |
| July | 7.6 | #2 | 76°F | 56°F | 11 | 8.7 | Steady all year |
| August | 7.6 | #1 | 77°F | 56°F | 9 | 8.8 | Steady all year |
| September | 7.4 | #4 | 70°F | 51°F | 7 | 8.6 | Steady all year |
| October | 6.5 | #7 | 61°F | 46°F | 12 | 6.7 | Steady all year |
| November | 5.7 | #9 | 51°F | 39°F | 13 | 5.1 | Steady all year |
| December | 5.0 | #11 | 46°F | 36°F | 16 | 4.0 | Steady all year |
Near here
Nearby regions, nearest first. Distances are centre to centre, as the crow flies; they are not road distances or journey times.
DüsseldorfGermany · about 40 miles
Balanced Overall 7.4 · Very good weather, 70°F (21°C) · Steady all year · Cost pricey
Maastricht & LimburgNetherlands · about 50 miles
Balanced Overall 7.2 · Very good weather, 70°F (21°C) · Busy season · Cost expensive
Frankfurt & southern HesseGermany · about 100 miles
Balanced Overall 7.6 · Very good weather, 71°F (22°C) · Steady all year · Cost pricey
Amsterdam & North HollandNetherlands · about 150 miles
Balanced Overall 6.8 · Very good weather, 68°F (20°C) · Busy season · Cost expensive
Weser-Ems & the North Sea coastLower Saxony · Germany · about 150 miles
Balanced Overall 7.0 · Very good weather, 68°F (20°C) · Busy season · Cost pricey
Elsewhere in Europe
Cologne & Bonn's weather ranks 29 of 41 city regions this month. These city regions outside Germany have clearly better weather on your dates, nearest first, each compared with Cologne & Bonn.
Hotel stays are steady all year here: this month is 93% of the busiest and 10% above average. That counts overnight stays, not how busy the sights are.The figures cover the whole Köln region, suburbs included. That means about 44,000 overnight visitors on a typical September night across the region, 72% of them from Germany itself. Rentals booked through Airbnb, Booking, Expedia and Tripadvisor add up to 6,600 more: 15 for every 100 counted above. Some are the same properties counted twice.
| Climate suitability (HCI:Urban, 0–100) | 78 |
| How our weather was checked | 10 open weather stations in this region, January and July: afternoon highs typically within 1°F (0.1°C), night lows within 1°F (0.7°C). |
| Tourist nights per 1,000 residents per day | 10 |
| Busiest month here | August · 11 |
| Visitors as share of people present | 1.0% |
| Rank among Europe's regions this month | 27th percentile |
| Domestic share of nights | 72% |
| Platform rental nights per 100 counted nights | 15 |
| Visitor share if every platform night were extra | 1.1% |
| National hotel-price season | Germany historical 2024–2025 index: About usual (+4% vs its average month). Not a local room quote. |
| Population used | 4.5 million |
| Statistical region | DEA2 · Köln |
Crowds: Eurostat nights spent at tourist accommodation, by month and NUTS 2 region, 2024–2025 average. Overnight visitors per night is the month's nights divided by its days; the per-1,000 figure is Eurostat's, against each year's population. Platform rentals: Eurostat nights booked via Airbnb, Booking, Expedia and Tripadvisor, 2024–2025 average, shown separately because some properties are in both counts. Weather: Holiday Climate Index computed from ERA5 reanalysis with daily highs, night lows and rain days corrected from open national weather-service station records, 2011–2025, population-weighted to the region; day-by-day figures are the same data averaged by date. Heat and rain odds are counted across those years. Sunrise and sunset: NOAA solar equations, local time. Prices: Eurostat price level index and HICP, national. Full method · this region's data.