Aachen climate
Aachen (North Rhine-Westphalia, Germany) has a temperate oceanic climate (Köppen Cfb). The average temperature over the year is 9 °C49 °F, and about 747 mm29 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Aachen climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 438 | −228 | 133 | 662.6 | 17 |
| Feb | 541 | −228 | 135 | 602.3 | 15 |
| Mar | 948 | 032 | 440 | 562.2 | 11 |
| Apr | 1457 | 338 | 948 | 421.7 | 4 |
| May | 1864 | 745 | 1254 | 612.4 | 0 |
| Jun | 2170 | 1151 | 1661 | 652.6 | 0 |
| Jul | 2374 | 1355 | 1864 | 732.9 | 0 |
| Aug | 2373 | 1254 | 1864 | 783.1 | 0 |
| Sep | 1967 | 948 | 1457 | 522.1 | 0 |
| Oct | 1457 | 542 | 1049 | 582.3 | 1 |
| Nov | 847 | 235 | 541 | 652.6 | 5 |
| Dec | 440 | −130 | 235 | 712.8 | 14 |
| Year | 2374 | −228 | 949 | 74729 | 66 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 91% | 79% | 0.8 | 8:25 |
| Feb | 88% | 76% | 1.5 | 9:57 |
| Mar | 83% | 70% | 2.7 | 11:43 |
| Apr | 77% | 66% | 4.2 | 13:45 |
| May | 76% | 71% | 4.9 | 15:29 |
| Jun | 74% | 71% | 5.4 | 16:28 |
| Jul | 71% | 68% | 5.2 | 16:04 |
| Aug | 72% | 67% | 4.4 | 14:31 |
| Sep | 75% | 64% | 3.3 | 12:32 |
| Oct | 83% | 71% | 1.9 | 10:35 |
| Nov | 90% | 79% | 0.9 | 8:51 |
| Dec | 92% | 81% | 0.6 | 7:58 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Aachen is like
The warmest month is July, with an average high of 23 °C74 °F and a low of 13 °C55 °F. The coldest is January, when highs average 4 °C38 °F and lows −2 °C28 °F. There is a clear seasonal cycle, with 17.3 °C31.1 °F between the average temperature of the warmest and the coolest month.
Annual precipitation is moderate at about 747 mm29 in. Rain is spread fairly evenly through the year. The wettest month is August (78 mm3.1 in), the driest is April (42 mm1.7 in).
Relative humidity ranges from 71% in July to 92% in December. The clearest skies (lowest average cloud amount, 64%) are typical of September. Average wind speed near the ground ranges from 9 km/h (6 mph) in August to 14 km/h (8 mph) in January. Daylight lasts from about 8.0 hours in December to 16.5 hours in June.
A lasting snow cover is typical in January, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, about 10 cm).
Best time to visit Aachen
Based on these averages, the most comfortable months for sightseeing and outdoor activities are June–September: average highs of 19 °C67 °F to 23 °C74 °F with 52 mm2.1 in to 78 mm3.1 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 4 °C38 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Aachen
- Winter (December–February) — highs 438 to 5 °C41 °F, lows −228 to −1 °C30 °F, about 66 mm2.6 in of precipitation a month. Pack a warm coat, layers and closed shoes and shoes with good grip, as frost is common.
- Spring (March–May) — highs 948 to 18 °C64 °F, lows 032 to 7 °C45 °F, about 53 mm2.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 2170 to 23 °C74 °F, lows 1151 to 13 °C55 °F, about 72 mm2.8 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Autumn (September–November) — highs 847 to 19 °C67 °F, lows 235 to 9 °C48 °F, about 58 mm2.3 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
How Aachen compares
Compared with Köln, about 63 km to the east, Aachen is on average 1.4 °C2.5 °F cooler and receives 6% less precipitation (747 mm29 in vs 791 mm31 in). The difference is largest in July (1.8 °C3.2 °F cooler).
Of the 62 places in Germany covered by World Climates, Aachen is the 55th warmest by annual mean temperature and the 33rd wettest by annual precipitation. See all of them on the Germany climate page.
Places in other countries with the most similar temperature and rainfall pattern: Luxembourg (Luxembourg, Cfb), Groningen (The Netherlands, Cfb) and Charleroi (Belgium, Cfb).
Nearby places
- Maastricht 29 km · 11 °C51 °F · 771 mm30 in
- Liège 40 km · 11 °C51 °F · 862 mm34 in
- Mönchengladbach 52 km · 11 °C51 °F · 747 mm29 in
- Köln 63 km · 11 °C51 °F · 791 mm31 in
- Düsseldorf 70 km · 11 °C51 °F · 791 mm31 in
- Krefeld 70 km · 10 °C50 °F · 791 mm31 in
- Bonn 71 km · 11 °C51 °F · 771 mm30 in
- Bergisch Gladbach 77 km · 10 °C51 °F · 791 mm31 in
Frequently asked questions
What is the warmest month in Aachen?
July is the warmest month in Aachen, with an average high of 23 °C (74 °F) and an average low of 13 °C (55 °F).
What is the coldest month in Aachen?
January is the coldest month, with an average high of 4 °C (38 °F) and an average low of -2 °C (28 °F).
When does it rain the most in Aachen?
August is the wettest month with about 78 mm (3.1 in) of precipitation; April is the driest with about 42 mm (1.7 in).
What is the best time to visit Aachen?
Judging by long-term averages, the most comfortable months are June–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 85 m, while Aachen lies at about 266 m. Temperatures on this page were therefore adjusted by −1.2 °C2.1 °F using the standard lapse rate of 6.5 °C per 1,000 m.