Bonn sits in the Rhine Valley in western Germany, giving it a temperate oceanic climate (Köppen Cfb) with mild winters and warm summers. The city gets about 670mm (26 inches) of rain annually spread across 130 rainy days, and temperatures range from an average January low of -1°C (30°F) to a July high of 24°C (75°F). See our Bonn travel tips for more details. The Rhine moderates extremes, so Bonn rarely sees the deep snow or scorching heat that other German cities at similar latitudes experience.
Bonn Weather by Month: Temperature and Rainfall
| Month | Avg High °C (°F) | Avg Low °C (°F) | Rainfall (mm) | Rainy Days | Sun Hours/Day |
|---|---|---|---|---|---|
| January | 5 (41) | -1 (30) | 50 | 11 | 1.5 |
| February | 7 (45) | 0 (32) | 40 | 9 | 2.5 |
| March | 11 (52) | 3 (37) | 45 | 10 | 3.5 |
| April | 15 (59) | 5 (41) | 45 | 9 | 5.0 |
| May | 19 (66) | 9 (48) | 60 | 10 | 6.0 |
| June | 22 (72) | 12 (54) | 70 | 11 | 6.5 |
| July | 24 (75) | 14 (57) | 70 | 11 | 6.5 |
| August | 24 (75) | 14 (57) | 65 | 10 | 6.0 |
| September | 20 (68) | 11 (52) | 55 | 9 | 4.5 |
| October | 15 (59) | 7 (45) | 50 | 9 | 3.0 |
| November | 9 (48) | 3 (37) | 55 | 11 | 1.5 |
| December | 6 (43) | 0 (32) | 55 | 12 | 1.0 |
Bonn Weather by Month: What to Expect
Winter (December to February)
Bonn winters are damp and grey rather than snowy. December and January average highs of 5-6°C (41-43°F) with overnight lows around -1°C (30°F). You will get 1 to 2.5 hours of sun per day and 11-12 rainy days per month. Snow falls 5-8 days per winter but rarely sticks for more than a day in the city center. The Christmas market on Münsterplatz runs from late November through December 23. Pack a waterproof coat, scarf, and gloves. See our where to stay in Bonn for more details. February is the driest month (40mm) and the first hint of spring appears with snowdrops in the Hofgarten.
Spring (March to May)
March warms to 11°C (52°F) by day with the cherry blossoms on Heerstrasse and Breite Strasse peaking in late March to mid-April. April averages 15°C (59°F) and is tied with February as the driest month (45mm, 9 rainy days). By May, daytime highs reach 19°C (66°F) and sunshine jumps to 6 hours per day. This is the best season for walking the Rhine promenade and exploring the Siebengebirge hills without summer crowds. Pack layers: mornings can still be chilly at 5°C (41°F) in April. See our best neighborhoods in Bonn for more details. Rain falls about once every three days, so carry a compact umbrella.
Summer (June to August)
July and August are the warmest months with average highs of 24°C (75°F) and lows of 14°C (57°F). Heatwaves can push temperatures above 32°C (90°F) for a few days, though this happens only 2-3 times per summer. June and July are the wettest months (70mm each) but rain often comes as short afternoon showers rather than all-day drizzle. You will get 6-6.5 hours of daily sunshine. The Rheinaue Park fills with sunbathers and the beer gardens along the Rhine open fully. Pack a light jacket for evenings and something waterproof if you are out after 4 PM when storms tend to roll in. See our Bonn events and festivals for more details. Museums and indoor attractions are air-conditioned but many restaurants and older buildings are not, so 30°C+ days can be uncomfortable in the Altstadt.
Autumn (September to November)
September stays pleasant at 20°C (68°F) with 55mm of rain and the Beethovenfest draws classical music fans through the month. October drops to 15°C (59°F) and the forests of the Kottenforst and Siebengebirge turn gold. November is the gloomiest month: 9°C (48°F), just 1.5 hours of daily sun, and the start of Karneval season on November 11 at 11:11 AM. See our Bonn travel guide for more details. Pack warm sweaters, a waterproof coat, and waterproof shoes for the muddy forest trails.
onn-best-time-to-visit/”>best time to visit Bonn for more details. Pack warm sweaters, a waterproof coat, and waterproof shoes for the muddy forest trails. onn-things-to-do/”>things to do in Bonn for more details. Pack warm sweaters, a waterproof coat, and waterproof shoes for the muddy forest trails.Bonn Weather by Month: Packing Tips
- A waterproof jacket with a hood is essential year-round: Bonn averages 130 rainy days and rain can arrive with little warning in any season.
- Comfortable waterproof walking shoes for the cobblestone Altstadt streets and the forest trails of the Siebengebirge.
- Layers work better than heavy coats. A thermal base layer and fleece under a shell jacket will handle 95% of Bonn winter days.
- Sunscreen and sunglasses for April through September when UV index reaches 5-7 on clear days.
- A compact travel umbrella fits in a daypack and is lighter than wearing rain gear all day in showery weather.
