May Weather in Nagano, Japan

Last updated: August 21, 2025

May in Nagano, Japan is a month of striking contrasts, marked by a maximum temperature of 31°C (88°F) and a refreshing average of 15°C (59°F), allowing for a delightful mix of warm days and cooler evenings. The month experiences substantial precipitation, with a total of 160 mm (6.3 in) falling over 16 days, creating a lush, vibrant landscape. Humidity levels hover around 81%, adding to the fragrant atmosphere of blooming nature. Whether you're exploring the scenic mountains or enjoying local festivities, May offers a captivating glimpse of Nagano's seasonal beauty.

May Temperature in Nagano

In May, Nagano ushers in a delightful transition from the lingering chill of spring to the warmth of summer. With temperatures ranging from a cool 0°C (33°F) at night to a pleasant 31°C (88°F) during the day, this month signifies a remarkable shift in weather. The average temperature of 15°C (59°F) invites outdoor enthusiasts to embrace the blooming landscapes and vibrant flora. As the region shakes off winter's grasp, the increasing warmth and longer daylight hours create the perfect setting for exploring Nagano's beautiful mountains and rich cultural heritage, promising an energizing start to the summer season.

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

The chart illustrates May temperature patterns in Nagano, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Nagano, May typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec293038485965727566564434
Data source: Temperature data for Nagano generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Nagano

In May, Nagano, Japan experiences a notable increase in precipitation, with an average of 160 mm (6.3 in) falling over 16 days. This uptick marks a significant shift from the drier months of April and March, reflecting the onset of the rainy season. The consistent rainfall not only contributes to the richness of the region’s vibrant landscapes but also indicates a trend of increasing moisture as the year progresses. Following May, the precipitation levels continue to rise through June and into the sizzling summer months, peaking in July with a dramatic 341 mm (13.4 in), highlighting Nagano's distinctive climatic pattern of early summer storms.

May Precipitation Trends in Nagano

The chart displays monthly precipitation patterns in Nagano, 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. In Nagano, May typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec14412913314116017134119819421794151
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Nagano

In May, the humidity in Nagano, Japan settles at a comfortable 81%, showing a slight increase from the drier months of April (78%) and a gentle dip from the high humidity expected in June (88%). This transitional month heralds the arrival of summer, where moisture in the air begins to rise noticeably. As we look at the broader trends, the humidity consistently hovers around the higher end from mid-spring to summer, peaking during the hotter months of July and August at a staggering 92%. Nagano’s climate thus presents a fascinating shift, balancing breezy spring conditions with the sultry embrace of summer, making May a refreshingly mild threshold into the seasonal warmth.

May Average Humidity in Nagano

This chart illustrates the average monthly humidity levels in Nagano, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Nagano is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%81%79%81%88%92%92%89%87%85%86%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Nagano

As May arrives in Nagano, Japan, the UV Index escalates dramatically, reaching an extreme level of 11. This marks a significant shift from earlier months, where the UV Index hovered around moderate to very high levels, peaking at 9 in both March and April. With the burn time dropping to just 10 minutes, it’s crucial for residents and visitors alike to take extra precautions when enjoying outdoor activities. The trend of intensifying UV exposure continues into June, July, and August, maintaining that extreme categorization. As the weather warms up, make sure to stay protected under the sun by checking the latest information on the Nagano UV Index.

Maximum UV Index Levels in Nagano for May

The chart shows the monthly maximum UV Index (UVI) for Nagano 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. In May, the maximum UV index in Nagano typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec46991111111110753
Data source: Nagano 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 Nagano

In Nagano, Japan, May marks a delightful transition into the warm embrace of spring, boasting an impressive 300 hours of sunshine. This surge in brightness is a welcome change from the brisk winter months, where January experienced only 174 hours of sunlight. As the months progress, there is a steady increase in sunlight hours, peaking in May before starting to decline in June. The vibrant sunshine not only illuminates the beautiful landscapes but also invites residents and tourists to bask in outdoor activities. With its lush surroundings blooming under the May sun, Nagano becomes a picturesque haven, showcasing the gentle shift from the cozy winter season to the lively vibrancy of spring and early summer.

Monthly Sunshine Duration in Nagano: May Highlighted

The May sunshine duration represents the total number of hours Nagano 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.
JanFebMarAprMayJunJulAugSepOctNovDec174h224h261h279h300h279h261h290h243h217h224h208h
Data source: Nagano May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Nagano During May

In Nagano, Japan, the likelihood of sunny weather significantly fluctuates throughout the year. April sees an encouraging 43% chance of sunshine, setting a vibrant tone for the spring season. However, as May arrives, this likelihood dips to a modest 25%, making it one of the less sunny months compared to its predecessor. This trend continues into June, where the chance of sun further decreases to 22%. Interestingly, the overall pattern reveals that while the peak sunshine occurs in early spring, the late spring and early summer months tend to be more cloud-covered, influencing plans for outdoor activities. As you navigate May, be prepared for an occasional overcast day, reminding us that Nagano's beauty often lies in its diverse weather.

Percentage of Sunny Days in May in Nagano

The chart illustrates the percentage of sunny days in Nagano 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 Nagano experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%39%32%43%25%22%31%22%25%35%42%34%
Data source: Nagano May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Nagano in May

In Nagano, Japan, the daylight duration experiences a steady climb from the depths of winter to the lush vibrance of spring and summer. Beginning with just 9 hours in January, daylight gradually lengthens, reaching 14 hours by both May and June, creating perfect conditions for outdoor adventures and exploring the region's stunning landscapes. Following this peak, daylight starts to wane slightly in the summer months, but it remains plentiful through August. As the year progresses into autumn, daylight gradually recedes, dropping to 12 hours in September and continuing its descent to 9 hours by December. This annual rhythm offers a beautiful showcase of nature's transition, making each month uniquely inviting in its own right.

Average Daylight Hours in Nagano for May

The chart illustrates the variation in daylight duration in Nagano throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 56m10h 49m11h 57m13h 8m14h 7m14h 37m14h 22m13h 30m12h 23m11h 13m10h 11m9h 40m
Data source: Nagano daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Nagano

In Nagano, Japan, the winds of May bring a gentle breeze, with an average speed of 1.9 m/s (4 mph). This calm pattern in May mirrors the stillness felt in both January and February, suggesting a consistency in the early spring air. As the region transitions into the warmer months, wind speeds subtly rise, peaking in April at 2.1 m/s (5 mph). However, despite the arrival of spring, May's winds remain soft, marking a tranquil period before the lighter summer breezes settle in, which are significantly lower, averaging around 1.4-1.5 m/s from June through August. This seasonal fluctuation highlights the unique, serene character of Nagano's May winds, offering a refreshing yet gentle experience for residents and visitors alike.

Average May Wind Speed in Nagano

The chart displays monthly wind speed patterns in Nagano, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.91.92.02.11.9 m/s1.41.31.51.61.61.61.8
Data source: Nagano May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Nagano Compares to Other Months

Weather in Nagano varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Nagano, focusing on differences in temperature, rainfall, humidity, and UV levels.

May and January offer contrasting weather experiences. In May, temperatures range from a chilly 0°C (33°F) to a warm 31°C (88°F), with an average of 15°C (59°F), marking the transition into summer. The month is characterized by significant rainfall, receiving about 160 mm (6.3 in) over roughly 16 days, coupled with a humidity level of 81%. In stark contrast, January presents much colder conditions, with temperatures plummeting to a minimum of -15°C (6°F) and a maximum of just 10°C (51°F), averaging -2°C (29°F). Although it sees slightly less precipitation at 144 mm (5.7 in), it experiences more rainy days, approximately 21, and a higher humidity of 88%. For more details on January conditions, check out Nagano weather in January.

Comparing the weather in May and February reveals a stark contrast. May experiences significantly warmer temperatures, with a minimum of 0°C (33°F) and an average of 15°C (59°F), while February sees much chillier conditions, starting at a minimum of -14°C (7°F) and averaging -1°C (30°F). Additionally, May enjoys a higher maximum temperature of 31°C (88°F) compared to February's peak of 16°C (61°F). In terms of precipitation, May receives more rainfall with 160 mm (6.3 in) over 16 days, while February records 129 mm (5.1 in) spread over 19 days, indicating slightly wetter conditions despite February's lower overall moisture content. Interestingly, February's humidity stands at 86%, only slightly above May's 81%. For more detailed information about February weather in Nagano, you can visit Nagano weather in February.

In comparing the weather of May and March, it's clear that May experiences milder and warmer temperatures with averages around 15°C (59°F) and a maximum reaching 31°C (88°F), while March has lower averages at around 4°C (39°F), peaking at 21°C (70°F). Precipitation is slightly higher in May, totaling 160 mm (6.3 in) over 16 days, compared to March's 133 mm (5.2 in) over 18 days. Interestingly, both months share the same humidity level of 81%, indicating that conditions can feel quite similar in terms of moisture content, despite the significant temperature differences. For a detailed overview of March weather, you can refer to Nagano weather in March.

In comparing the weather of May and April, May generally experiences warmer temperatures, with an average of 15°C (59°F) compared to April's 9°C (48°F). The maximum temperature in May can reach up to 31°C (88°F), significantly higher than April's 27°C (81°F). Both months see a similar number of rainy days, with May registering 160 mm (6.3 in) of precipitation over 16 days, slightly more than April's 141 mm (5.5 in) over the same number of days. Humidity levels also rise in May to 81%, compared to April's 78%, making May feel more humid overall. For more details about April weather, visit Nagano weather in April.

In comparing the weather between May and June, a few notable differences emerge. May experiences a broader temperature range with minimums reaching as low as 0°C (33°F) and maximums peaking at 31°C (88°F), while June sees slightly milder temperatures with a minimum of 5°C (41°F) and a maximum of 30°C (87°F). Precipitation increases in June, with 171 mm (6.7 in) falling over 18 days compared to May's 160 mm (6.3 in) across 16 days. Additionally, both months have high humidity levels, but June is slightly more humid at 88% compared to May's 81%. For more detailed insights, you can check out Nagano weather in June.

May and July weather conditions present a marked contrast. In May, temperatures range from a chilly 0°C (33°F) at night to a pleasant average of 15°C (59°F) during the day, with a maximum reaching 31°C (88°F). However, this month experiences significant precipitation, with about 160 mm (6.3 in) falling over 16 days and humidity levels at 81%. In contrast, July sees warmer temperatures, with nighttime lows around 15°C (60°F) and daily averages climbing to 22°C (73°F), peaking at a hot 33°C (91°F). This month is notably wetter as well, with 341 mm (13.4 in) of rain over 25 days and higher humidity at 92%. For more details, you can check Nagano weather in July.

May and August present distinct weather patterns. In May, temperatures range from a cool 0°C (33°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). However, it is also a relatively wet month, experiencing around 160 mm (6.3 in) of precipitation over 16 days, combined with a humidity level of 81%.

In contrast, August sees warmer conditions with a minimum temperature of 11°C (52°F) and a maximum of 35°C (95°F), leading to an average temperature of 24°C (75°F). This month is also wetter, with precipitation totaling 198 mm (7.8 in) across 23 days, and even higher humidity at 92%. For a more detailed look at the August weather patterns, you can refer to Nagano weather in August.

In May, temperatures can range from a chilly 0°C (33°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). This month sees about 160 mm (6.3 in) of precipitation spread over 16 days, with a humidity level of 81%. In contrast, September experiences slightly milder temperatures, with nighttime lows of 7°C (44°F) and daytime highs reaching 32°C (89°F), averaging around 19°C (67°F). However, September tends to be wetter, accumulating 194 mm (7.6 in) of rain over 19 days and a slightly higher humidity of 89%. For more detailed information on September weather, you can visit Nagano weather in September.

In comparing the weather of May and October, we see distinct differences in temperature and precipitation patterns. May boasts a wider temperature range, with a minimum of 0°C (33°F) and highs reaching up to 31°C (88°F), while October offers milder conditions, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 28°C (82°F). Precipitation is notably higher in October, accumulating 217 mm (8.5 in) over 18 days compared to May's 160 mm (6.3 in) spread across 16 days. Additionally, October exhibits slightly higher humidity levels at 87%, compared to May's 81%. For more detailed information, you can check out Nagano weather in October.

May and November in Nagano present contrasting weather patterns that reflect the transition between spring and late autumn. During May, temperatures range from a chilly minimum of 0°C (33°F) to a warm maximum of 31°C (88°F), with an average of 15°C (59°F), accompanied by significant precipitation of 160 mm (6.3 in) over 16 days and humidity levels at 81%. In contrast, November features cooler temperatures, with a minimum of -8°C (19°F) and a maximum of 21°C (70°F), averaging 7°C (44°F). While precipitation is lower at 94 mm (3.7 in) over 15 days, humidity slightly increases to 85%. For more details, check out Nagano weather in November.

May and December offer contrasting weather experiences. In May, temperatures can range from a chilly 0°C (33°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). This month sees a fair amount of precipitation, totaling 160 mm (6.3 in) over 16 rainy days, while humidity hovers around 81%. In stark contrast, December features much colder temperatures, with lows dropping to -10°C (14°F) and a maximum of 19°C (66°F), averaging just 1°C (34°F). The month also experiences a slightly lower total precipitation of 151 mm (6.0 in) spread over 20 days, with humidity increasing to 86%. For more specific December weather insights, you can check out Nagano weather in December.

Compare Nagano's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Nagano

As spring transitions into summer, May in Nagano offers a vibrant tapestry of weather experiences. This month stands out with fluctuating temperatures that can reach a pleasant maximum, making it warmer compared to the cooler months preceding it. Frequent rainfall, arriving on nearly half the days, brings lush greenery to the landscapes, contrasting with the drier spells of earlier spring. With an average humidity level that lingers, the air feels thick and alive, sometimes leading to a refreshing, albeit damp ambience. The overall climate in May presents a blend of warmth and moisture, setting the stage for nature's full bloom. For a detailed look at the yearly weather patterns, visit Nagano Climate.