Bonn has a temperate oceanic climate with mild, sometimes humid summers and cool, damp winters. Summer highs reach 23–25°C, while winter lows can dip just below freezing. Rainfall is spread throughout the year, with no true dry season, and sunshine is most abundant in late spring and summer. The weather is famously changeable, so packing layers is wise.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colors of the months:
The color shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the color is shows the travel season: full color means high season, soft color means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The gray info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Bonn’s climate is shaped by its location in the Rhine Valley and its proximity to the Atlantic, resulting in moderate temperatures and frequent rainfall year-round. Summers (June–August) are mild to warm, with average highs of 22–25°C and lows around 12–14°C. July is typically the warmest month, and occasional heatwaves can push temperatures above 30°C. Humidity is often high, making some summer days feel muggy, but evenings tend to be cooler. Rain is common in summer, especially in June and July, with monthly averages of 75–90 mm, though showers are often brief and followed by sunny intervals. Sunshine peaks in late spring and summer, with up to 7 hours per day in June and July, and daylight can last up to 16 hours in midsummer.
Winters (December–February) are cool and damp, with average highs of 4–7°C and lows near or just below 0°C. Snow is possible but usually light and short-lived, with 10–15 days of snow per year. Rain is frequent, especially in December and January, and the city often experiences overcast skies and high humidity. Spring (March–May) and autumn (September–November) are transitional, bringing variable weather, moderate rainfall, and temperatures ranging from 8°C in March to 19°C in May, and cooling from 19°C in September to 6°C in November. Bonn receives 700–800 mm of rain annually and about 1,600–1,700 hours of sunshine, with the sunniest months from May to August. Winds are generally light to moderate, with breezier days in autumn and winter.
| Average climate data for Bonn, Germany | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°F) | 39 | 41 | 50 | 59 | 64 | 70 | 74 | 74 | 66 | 57 | 48 | 42 | 74 |
| Average minimum temperature (°F) | 31 | 31 | 35 | 41 | 46 | 51 | 55 | 56 | 50 | 44 | 39 | 34 | 31 |
| Average precipitation (inch) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 12 |
| Average rainfall days (days) | 13 | 10 | 14 | 12 | 15 | 15 | 16 | 14 | 11 | 12 | 13 | 14 | 156 |
| Average snowfall (inch) | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 4 |
| Average snowfall days (days) | 6 | 5 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 5 | 20 |
| Average relative humidity (%) | 88 | 83 | 79 | 75 | 77 | 78 | 73 | 72 | 77 | 82 | 87 | 89 | 80 |
| Average wind speed (mph) | 8 | 8 | 7 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 7 | 8 | 7 |
| Average daily daylight hours (h) | 8 | 10 | 11 | 13 | 15 | 16 | 16 | 14 | 12 | 10 | 9 | 8 | 12 |
| Average daily sunshine hours (h) | 4 | 4 | 6 | 9 | 9 | 9 | 9 | 9 | 8 | 5 | 4 | 3 | 7 |
| Average cloud coverage (%) | 60 | 59 | 50 | 38 | 44 | 43 | 38 | 37 | 40 | 48 | 57 | 63 | 48 |
| Average UV index | 2 | 2 | 3 | 3 | 4 | 5 | 5 | 4 | 4 | 3 | 2 | 2 | 3 |
The best time to visit Bonn is from May to September, when temperatures are mild to warm (18–25°C), days are long, and gardens and parks are in full bloom. These months offer the best conditions for outdoor sightseeing, festivals, and river walks, though rain showers are still possible. Spring is especially beautiful during cherry blossom season in April.
The least favorable time to visit is from November to February. These months are the coldest and wettest, with highs of 4–7°C, frequent rain, short daylight hours, and occasional snow or wind. While the city is quieter and festive markets bring charm, outdoor sightseeing is less appealing due to damp, chilly weather.
Bonn has mild, sometimes humid summers (22–25°C) and cool, damp winters (4–7°C). Rain falls in all months, and the weather is changeable, so it’s wise to pack layers and a rain jacket.
Snow is possible in Bonn, mostly from December to February, but it is usually light and melts quickly. Most winters see only a few days of snow, with rain being much more common.
May through August are the sunniest months in Bonn, with up to 7 hours of sunshine per day and long daylight hours. These months are ideal for outdoor activities and sightseeing.
Bonn receives about 700–800 mm of rain annually, with rain possible in any month. June and July are the wettest months, while April and February are usually the driest.
Pack layers, a rain jacket or umbrella, and comfortable waterproof shoes. Even in summer, evenings can be cool, and rain is frequent. A warm coat is recommended for winter visits.
Humidity in Bonn is generally high, especially in summer and winter. Summer days can feel muggy, while dampness in winter can make the cold feel more intense.
Bonn is least crowded in winter (January–February) and late autumn (November), when the weather is coldest and wettest. Spring and autumn offer fewer tourists than summer, but weather can be variable.
The warmest month, with the highest average maximum temperature, is July (74.1 °F). The month with the lowest average maximum temperature is January (39.3 °F). Overall, the average maximum temperature over the whole year is 57 °F.
The month with the highest average minimum temperature is August (56.1 °F). The coldest month, with the lowest average minimum temperature, is January (31.3 °F). Overall, the average minimum temperature over the whole year is 42.9 °F.
The wettest month, with the highest amount of precipitation, is August (1.3 inch). The driest month, with the least amount of precipitation, is September (0.7 inch). Over the whole year there are 12 inch of rainfall on average.
The month with the most days of rain is July (15.6 days). The month with the fewest days of rain is February (10.4 days). Over the whole year there are 156.1 days of rain on average.
The month with the most snowfall is February (1.4 inch). The months with the least snowfall are April, May, June, July, August, September and October (0 inch). Over the whole year there are 3.9 inch of snowfall on average.
The month with the most days of snowfall is January (6 days). The months with the fewest days of snowfall are May, June, July and September (0 days). Over the whole year there are 19.8 days of snowfall on average.
The month with the highest average relative humidity is December (88.8 %). The month with the lowest average relative humidity is August (71.9 %). The overall average relative humidity over the whole year is 80 %.
The windiest month, with the highest average wind speed, is February (8 mph). The calmest month, with the lowest average wind speed, is August (5.5 mph). The overall average wind speed over the whole year is 6.7 mph.
The month with the cloudiest skies, so the highest cloud coverage, is December (63 %). The month with the clearest skies, so the lowest cloud coverage, is August (37.1 %). Over the whole year there is an average cloud coverage of 48.1 %.
The month with the longest days, so the most daylight, is June (Average daylight: 16 h). The month with the shortest days, so the least daylight, is December (Average daylight: 8 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is July (Average sunshine: 9.1 h). The month with the least sunshine per day is December (Average sunshine: 3 h). Over the whole year there are 6.6 h of sunlight per day on average.
The months with the highest average UV index are June and July (UV index: 5). The months with the lowest average UV index are January, February, November and December (UV index: 2). Over the whole year the average UV index is 3.2.
