May Weather in Koeln, Germany

Last updated: February 26, 2025

In May, Koeln, Germany experiences a dynamic climate characterized by warm temperatures and moderate rainfall. With a maximum temperature soaring up to 33°C (91°F), the month offers pleasant days, while the average temperature rests at a comfortable 14°C (57°F). Despite the mild beginnings, nighttime can dip to a brisk 0°C (33°F). May also brings 66 mm (2.6 in) of precipitation over 13 days, contributing to the city's vibrant greenery. The humidity levels hover around 77%, creating a refreshing atmosphere that enhances the charm of this historic city during springtime.

May Temperature in Koeln

In May, temperatures in Köln, Germany begin to rise significantly, signaling the arrival of spring in full swing. With a minimum temperature of 0°C (33°F) and a comfortable average of 14°C (57°F), the city experiences a delightful transition from the chill of winter. The maximum temperature can soar as high as 33°C (91°F), highlighting the potential for warm, sunny days perfect for outdoor activities and exploring the lush scenery. Compared to the preceding months, where temperatures hovered around freezing at times, May offers a refreshing warmth that invites both locals and visitors to enjoy the city's vibrant atmosphere. As a result, this month is not just a warm-up for the summer ahead, but a celebration of spring's full bloom with pleasant weather becoming a hallmark of the season in Köln.

May Weather in Koeln: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Koeln, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec384145505766676760544541
Data source: Temperature data for Koeln generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Koeln

In May, Koeln experiences a notable shift in weather patterns, with precipitation amounting to 66 mm (2.6 in) over approximately 13 days of rainfall. This marks an increase from the drier month of April, which saw just 38 mm. The transition to May signifies a gradual rise in moisture, as temperatures warm and spring takes hold, setting the stage for the wetter summer months that follow. Despite receiving less rain than both January and March—each with around 91 mm—May's precipitation totals remain substantial, showcasing an essential part of the region's climate as it nourishes the blooming flora while maintaining a delicate balance of sunshine and showers.

May Precipitation Trends in Koeln

The chart displays monthly precipitation patterns in Koeln, with values for each month alongside May's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec9186913866609778659767127
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Koeln

In May, the city of Koeln experiences a noticeable decline in humidity, averaging 77%, marking a shift towards drier conditions as spring transitions into summer. This represents a significant drop from the 84% humidity recorded in April, indicating a trend of decreasing moisture levels as the year progresses, continuing the pattern seen from the peak of 91% in January. As the summer months approach, the humidity continues to decline, reaching its lowest point of 72% in July. However, this reduction is not permanent; humidity begins to rise again in the fall, illustrating the seasonal oscillation between moist and drier air throughout the year in this vibrant German city.

May Average Humidity in Koeln

This chart illustrates the average monthly humidity levels in Koeln, with May's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how May's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec91%90%87%84%77%74%72%71%81%88%91%92%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Koeln

As May unfolds in Koeln, Germany, the UV Index climbs to 7, indicating a high exposure category and a burn time of just 25 minutes. This marks a significant rise from the earlier months, where the UV levels were relatively low to moderate. The transition from the milder indices of January (UV 1) through April (UV 5) highlights the burgeoning strength of the sun as summer approaches. As we delve into the sunny days of May, it's crucial for residents and visitors alike to take precautions against overexposure. With the UV index set to soar even higher in June, ensuring sensible sun safety practices becomes all the more important. For more detailed information on UV levels throughout the year, check out Koeln UV Index.

Maximum UV Index Levels in Koeln for May

The chart shows the monthly maximum UV Index (UVI) for Koeln in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Koeln May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Koeln

In Koeln, Germany, May heralds the arrival of vibrant sunshine, boasting an impressive 387 hours of sunlight. This surge marks a delightful transition from the darker winter months, where January sees just 113 hours. As spring unfolds, the average sunlight hours steadily increase, peaking in May before a gradual decline in the summer months, notably in July with 405 hours. This trend highlights how the days lengthen and the warmth blossoms, offering a perfect backdrop for outdoor activities. The gradual dip in hours from August onward signals the onset of autumn, but May remains a cherished month, encapsulating the joy of longer days and the lush surroundings that the season brings.

Monthly Sunshine Duration in Koeln: May Highlighted

The May sunshine duration represents the total number of hours Koeln experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec113h202h267h336h387h383h405h377h313h232h183h129h
Data source: Koeln May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Koeln During May

In May, Cologne, Germany experiences a 29% chance of sunny weather, marking a slight dip from the sunnier months of March and April. This trend indicates that while spring is still in full bloom, the likelihood of sunshine begins to taper as the season transitions toward summer. Compared to the fleeting brightness of early March (41%) and the stable warmth of April (38%), May offers a mix of sunny spells and overcast days. As we look ahead, the chances of clear skies remain relatively consistent through the early summer months of June and July, suggesting that the unpredictability of May paves the way for a more stable sunny climate in the months to follow.

Percentage of Sunny Days in May in Koeln

The chart illustrates the percentage of sunny days in Koeln throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Koeln experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec9%32%41%38%29%31%31%33%36%28%23%13%
Data source: Koeln May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Koeln in May

As spring unfolds in Koeln, Germany, the length of daylight begins to flourish, reaching a peak in May with an invigorating 15 hours of sunlight. This upward trend is evident from the earlier months; starting January with just 8 hours, the days gradually stretch longer, adding two hours in February and another hour in March. By April, the warmth of the season is palpable with 13 hours, paving the way for the vibrant light of May. Following May, daylight begins to taper off slightly, peaking again in June at 16 hours before transitioning into the summer months. This cyclical dance of daylight illustrates the rhythm of Koeln's seasons, inviting residents and visitors alike to revel in the embrace of each sunlit hour.

Average Daylight Hours in Koeln for May

The chart illustrates the variation in daylight duration in Koeln throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 27m10h11h 55m13h 52m15h 34m16h 27m15h 59m14h 27m12h 34m10h 38m8h 53m7h 58m
Data source: Koeln daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Koeln

In May, Koeln experiences a refreshing average wind speed of 3.6 m/s (about 8 mph), a moderate breeze that complements the city's blooming beauty. This slight uptick from the previous month, April's 3.1 m/s, hints at the transition into the warmer months. Compared to the windier winter months, where speeds hover closer to 3.7 m/s in January and 3.9 m/s in February, May brings a gentle caress of air that makes outdoor activities particularly enjoyable. As the summer approaches, it’s interesting to note that the wind speed tends to taper off, dipping to its lowest in June (2.5 m/s). Thus, May stands out as a delightful interlude where the winds are just right for picnics and strolls along the Rhine, inviting residents and visitors alike to embrace the vibrant spring ambiance.

Average May Wind Speed in Koeln

The chart displays monthly wind speed patterns in Koeln, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.73.93.53.13.6 m/s2.52.73.02.43.82.83.5
Data source: Koeln May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Koeln Compares to Other Months

The weather in Koeln changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of May's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Koeln and find detailed weather information for every month.

May and January showcase stark contrasts in weather patterns. In May, temperatures range from a chilly 0°C (33°F) to a warm 33°C (91°F), averaging a comfortable 14°C (57°F). The month sees approximately 66 mm (2.6 in) of precipitation spread over 13 days, with humidity levels at 77%. In contrast, January experiences much colder temperatures, with lows dropping to -8°C (17°F) and an average of just 3°C (38°F), peaking at 15°C (59°F). This winter month is wetter, with around 91 mm (3.6 in) of precipitation across 15 days and a higher humidity level at 91%. For more detailed information on January weather patterns, visit Koeln weather in January.

May and February exhibit distinctly different weather patterns. In May, temperatures range from a chilly minimum of 0°C (33°F) to a warm maximum of 33°C (91°F), with an average temperature of 14°C (57°F). In contrast, February presents colder conditions, with temperatures dropping as low as -9°C (16°F) and peaking at 20°C (68°F), averaging around 5°C (41°F). Precipitation is slightly lower in May at 66 mm (2.6 in) compared to February's 86 mm (3.4 in), yet both months experience rainfall on about 13 days. Humidity levels are higher in February at 90%, compared to May's 77%. For more details on February weather, check Koeln weather in February.

The weather in May is generally warmer than in March, with temperatures ranging from a minimum of 0°C (33°F) to a maximum of 33°C (91°F), while March sees lower temperatures, with a minimum of -9°C (16°F) and a maximum of 22°C (72°F). In May, the average temperature is a comfortable 14°C (57°F), compared to March's average of just 7°C (45°F). Interestingly, while March experiences slightly more precipitation at 91 mm (3.6 in) over 15 days, May still has notable precipitation levels at 66 mm (2.6 in) over 13 days, albeit with slightly lower humidity at 77% compared to March's 87%. For more details on the weather during March, you can visit Koeln weather in March.

In comparing the weather between April and May, we see a notable increase in temperatures as spring progresses. April experiences cooler temperatures with a minimum of -3°C (26°F) and an average of 10°C (51°F), while May enjoys milder conditions, ranging from a minimum of 0°C (33°F) to an average of 14°C (57°F). Additionally, May can reach higher maximum temperatures of up to 33°C (91°F), compared to April's peak of 27°C (81°F). However, May also brings more precipitation, with 66 mm (2.6 in) over 13 days, contrasting with April's 38 mm (1.5 in) over 9 days. Humidity levels are slightly lower in May at 77%, while April sees a higher average of 84%. For detailed insights on April's weather, check out Koeln weather in April.

May and June weather show a noticeable transition as temperatures rise and conditions become slightly drier. In May, temperatures range from a chilly 0°C (33°F) at night to a warm 33°C (91°F) during the day, with an average of 14°C (57°F), accompanied by a higher humidity level of 77%. Precipitation is also frequent, falling on 13 days for a total of 66 mm (2.6 in).

In contrast, June brings warmer nights with minimum temperatures of 8°C (46°F) and an overall average of 19°C (67°F). The maximum temperature can reach up to 35°C (95°F), making it the hottest month in this comparison. Rainfall decreases slightly to 60 mm (2.4 in) over 10 days, and humidity drops to 74%. For those looking for detailed weather specifics, check out Koeln weather in June.

In May, temperatures generally range from a chilly minimum of 0°C (33°F) to a comfortable average of 14°C (57°F), with the potential for warmer days peaking at 33°C (91°F). The month also sees considerable precipitation, with 66 mm (2.6 in) falling over 13 days and humidity levels at a relatively high 77%. In contrast, July experiences a more stable warmth, with temperatures starting at a minimum of 8°C (48°F) and reaching an average of 20°C (68°F), topping out at an impressive 40°C (104°F). Rainfall increases slightly to 97 mm (3.8 in) spread across 12 days, while humidity decreases to 72%. This highlights a notable shift in weather patterns from the transitional conditions of May to the hot summer days of July. For further details on what to expect, you can check Koeln weather in July.

When comparing the weather in May and August, notable differences emerge. May starts off with cooler temperatures, ranging from a minimum of 0°C (33°F) to a maximum of 33°C (91°F), with an average temperature of 14°C (57°F). It also experiences around 66 mm (2.6 in) of precipitation over 13 days, coupled with a high humidity level of 77%. In contrast, August presents a warmer climate, with temperatures ranging from a minimum of 7°C (44°F) to a maximum of 37°C (99°F) and an average of 20°C (68°F). Although it has slightly more precipitation at 78 mm (3.1 in) over 14 days, the humidity is a bit lower at 71%. For more specific details, you can check Koeln weather in August.

May and September exhibit similar temperature ranges, but September tends to be slightly warmer on average, with a minimum of 3°C compared to May's 0°C. Both months experience comparable maximum temperatures, peaking at 34°C in September and 33°C in May. Precipitation levels are also close, with May averaging 66 mm over 13 days and September at 65 mm over just 10 days, making September slightly drier. The humidity in September is marginally higher at 81%, compared to May's 77%. For more insights into September's weather, you can check Koeln weather in September.

In comparing the weather of May and October, we see notable differences in temperature and precipitation. May enjoys a wider temperature range, with minimums around 0°C (33°F) and maximums peaking at 33°C (91°F), offering an average of 14°C (57°F). In contrast, October features more moderate temperatures, with minimums of 1°C (34°F) and maximums reaching 27°C (80°F), averaging around 12°C (54°F). Precipitation is also higher in October, with 97 mm (3.8 in) over 15 days compared to May's 66 mm (2.6 in) across 13 days. Moreover, October experiences a higher humidity level at 88% compared to May's 77%. For more details on the October weather in Cologne, check out Koeln weather in October.

The weather in May and November showcases a stark contrast in temperatures and conditions. In May, temperatures range from a minimum of 0°C (33°F) to a maximum of 33°C (91°F), with an average of 14°C (57°F), providing a warm and pleasant atmosphere. In contrast, November experiences cooler temperatures, ranging from a low of -4°C (26°F) to a high of 20°C (68°F), with an average of just 7°C (45°F). While both months see similar precipitation levels, each month experiences it over the same number of days; May has 66 mm (2.6 inches) of rainfall over 13 days, and November has 67 mm (2.6 inches) also across 13 days. Additionally, humidity is notably higher in November at 91%, compared to May's 77%, contributing to a damp and chilly feel as winter approaches. For more specific details, you can check Koeln weather in November.

In May, temperatures are milder, ranging from a minimum of 0°C (33°F) to a maximum of 33°C (91°F), with an average of 14°C (57°F). This month experiences moderate precipitation of 66 mm (2.6 in) over about 13 days, coupled with a humidity level of 77%. In contrast, December is much colder, with temperatures fluctuating between a minimum of -5°C (24°F) and a maximum of 15°C (59°F), averaging just 5°C (41°F). Additionally, December sees higher precipitation at 127 mm (5.0 in) spread over 20 days, and increased humidity at 92%. For more details, you can visit Koeln weather in December.

Compare Koeln's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Koeln

May in Koeln ushers in a vibrant transition from the chill of early spring to the warmth of summer. With temperatures reaching highs of 33°C (91°F), the month stands out for its ability to offer a mix of blooming nature and inviting outdoor activities. Though the average temperature settles at a mild 14°C (57°F), notable fluctuations can occur, with chilly nights dropping to 0°C (33°F). While the days may be sunnier, expect occasional rain, as evidenced by the 66 mm (2.6 in) of precipitation over 13 days, contributing to a humidity level of around 77%. This combination of warmth and moisture cultivates a lush backdrop, making May a distinct month in Koeln's climate calendar. To learn more about the weather conditions throughout the year, visit Koeln Climate.