May Weather in Selfoss, Iceland

Last updated: March 17, 2025

May in Selfoss, Iceland unveils a fascinating blend of spring warmth and unpredictable weather. With maximum temperatures reaching 16°C (61°F) and an average hovering around 7°C (44°F), this month signals a transition into the lighter, longer days ahead. However, be prepared for cooler moments, as temperatures can dip to a minimum of -3°C (27°F). The landscape is nourished by a substantial precipitation amount of 128 mm (5.0 in) across 18 days, fostering the lush greenery Iceland is known for. Coupled with a humidity level of 83%, May’s weather in Selfoss presents a refreshing, though often damp, experience for both visitors and residents alike.

May Temperature in Selfoss

In May, Selfoss, Iceland, begins to shed its winter coat, revealing a gentle transition to spring. With nighttime temperatures dipping to a cool -3°C (27°F), the days grow noticeably warmer, featuring average highs of 16°C (61°F). This marks a significant increase from the preceding months, which often lingered around freezing. As the landscape bursts into life, the average temperature rises to 7°C (44°F), inviting outdoor enthusiasts to explore the striking natural beauty of the region. May's mild weather truly heralds the arrival of summer, setting the stage for longer, sunnier days ahead.

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

The chart illustrates May temperature patterns in Selfoss, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec323234394449535247413533
Data source: Temperature data for Selfoss 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 Selfoss

In Selfoss, Iceland, May marks a transition into the bustling spring with a precipitation total of 128 mm (5.0 in) spread over 18 days. This month experiences a dip in rainfall compared to the preceding April, which recorded 140 mm, indicating a gradual easing of spring showers. While May's precipitation aligns closely with November's, the frequency of rainy days enhances the lush, green landscapes characteristic of Iceland in springtime. As we look ahead to June, the average precipitation drops further to 89 mm, signaling a shift toward drier conditions during the summer months. The overall trend hints at a vibrant environment, nourished by the consistent rain earlier in the season, setting the stage for the natural beauty that Iceland is famed for.

May Precipitation Trends in Selfoss

The chart displays monthly precipitation patterns in Selfoss, 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.
JanFebMarAprMayJunJulAugSepOctNovDec142158121140128898696194113128137
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Selfoss

In Selfoss, Iceland, May experiences a moderate humidity level of 83%, slightly lower than the preceding months of February through April. The humidity levels throughout the year display a subtle trend of fluctuation, with January's peak at 84% and a steady rise from 81% in April to 86% in July. Notably, the summer months tend to bring higher humidity, with August and September reaching 87%, before gradually tapering off in the fall. This seasonal pattern indicates a period of heightened moisture content in the air, contributing to the lush landscapes that Iceland is renowned for.

May Average Humidity in Selfoss

This chart illustrates the average monthly humidity levels in Selfoss, 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.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%85%81%83%82%86%87%87%88%85%84%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Selfoss

As we move into May, Selfoss experiences a noticeable uptick in the UV Index, reaching 5 and categorizing exposure as moderate with a burn time of just 30 minutes. This rise marks a shift from the milder levels seen in the earlier months, where the UV Index hovered between 1 and 3. With spring in full bloom, the increasing sunlight means it’s essential to be mindful of sun exposure, especially as the days grow longer. This trend continues into June and July, when the UV Index escalates further, indicating a need for protective measures. For a detailed look at the UV Index trends throughout the year, check out Selfoss UV Index.

Maximum UV Index Levels in Selfoss for May

The chart shows the monthly maximum UV Index (UVI) for Selfoss 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.
JanFebMarAprMayJunJulAugSepOctNovDec112356643211
Data source: Selfoss 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 Selfoss

In Selfoss, Iceland, May shines as a beacon of light with 334 hours of sun, marking a significant leap from the previous months. As winter's grasp loosens, the days grow longer and brighter, heralding the arrival of spring. Following April's 212 hours, May exemplifies the upward trajectory of daylight hours, setting the stage for summer, which maintains a splendid average of around 310 hours from June to July. This trend highlights the stark contrast between the sun-drenched months and the bleakness of winter, where January barely sees 39 hours of sunshine. As the year progresses towards its sunnier peak, residents and visitors alike can revel in the vibrant warmth and beauty that May brings to this enchanting corner of Iceland.

Monthly Sunshine Duration in Selfoss: May Highlighted

The May sunshine duration represents the total number of hours Selfoss 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.
JanFebMarAprMayJunJulAugSepOctNovDec39h88h193h212h334h329h310h298h194h142h74h29h
Data source: Selfoss May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Selfoss During May

As spring transitions into summer, the likelihood of enjoying sunny weather in Selfoss, Iceland notably increases in May, where the chance of sunshine rises to 42%. This marks a significant improvement from the bleakness of the preceding winter months, with January's sun likelihood at just 33%. While April offers a hint of brightness at 26%, it’s in May that residents and visitors alike can truly bask in the warmth of the sun, embracing the longer days ahead. As the sunshine probabilities dip again in the summer months of June and July, May stands out as a delightful peak in the annual weather cycle, promising a refreshing reprieve from the cooler, cloudier days of earlier seasons.

Percentage of Sunny Days in May in Selfoss

The chart illustrates the percentage of sunny days in Selfoss 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 Selfoss experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec33%15%17%26%42%15%15%11%13%25%22%18%
Data source: Selfoss May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Selfoss in May

In Selfoss, Iceland, the evolution of daylight throughout the year reveals a stunning transformation, especially in May. Starting at a mere 5 hours in January, daylight steadily increases, reaching 18 hours by May, marking the onset of near-summer splendor. This significant leap illustrates how the days stretch dramatically as spring unfolds, reflecting the increasing warmth and vitality of the season. Following May, daylight peaks in June with an impressive 20 hours, creating an atmosphere ripe for exploration and outdoor adventures. However, as summer fades, the daylight begins its gradual retreat, signaling a return to shorter days that usher in autumn and winter. This rhythm of light and dark captures the essence of Iceland's unique seasonal beauty, inviting both residents and visitors to savor every moment under the midnight sun.

Average Daylight Hours in Selfoss for May

The chart illustrates the variation in daylight duration in Selfoss throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec5h 35m8h 35m11h 50m15h 8m18h 25m20h 40m19h 22m16h 11m12h 55m9h 40m6h 29m4h 26m
Data source: Selfoss daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Selfoss

In Selfoss, Iceland, the wind patterns throughout the year reveal intriguing trends. January and February kick off the year with a steady average wind speed of 3.9 m/s (9 mph), offering a chill in the air that gradually softens as spring approaches. By March, there’s a slight decrease to 3.7 m/s (8 mph), and the wind continues to lighten, reaching 3.4 m/s (8 mph) in April. The gentlest breezes of the year are felt in May, where the average dips to just 2.9 m/s (6 mph), providing a serene atmosphere perfect for enjoying nature's bloom. As summer unfolds, winds remain relatively mild through July and August, maintaining averages around 3.0 m/s (7 mph) and 2.7 m/s (6 mph), respectively. A noticeable increase returns in September with winds picking up to 4.1 m/s (9 mph), signaling the transition into the colder months. Overall, these trends depict a dynamic interplay of calm and gusty conditions, highlighting the unique atmospheric charm of Selfoss throughout the seasons.

Average May Wind Speed in Selfoss

The chart displays monthly wind speed patterns in Selfoss, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.93.93.73.42.9 m/s3.33.02.74.13.83.73.5
Data source: Selfoss May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Selfoss Compares to Other Months

The weather in Selfoss 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 Selfoss and find detailed weather information for every month.

In comparing the weather of May and January, it’s evident that May offers a more moderate climate with average temperatures ranging from -3°C (27°F) to a pleasant 16°C (61°F), while January experiences much colder conditions, with temperatures averaging between -14°C (7°F) and 10°C (50°F). Although May sees more days of precipitation (18 days compared to January's 15), the total rainfall is slightly lower, with May receiving 128 mm (5.0 in) versus January's 142 mm (5.6 in). Humidity levels are comparable, with May at 83% and January slightly higher at 84%. For those interested in exploring January specific weather patterns, you can find more details here: Selfoss weather in January.

May and February present quite different weather patterns. In February, temperatures typically linger around a chilly average of 0°C (32°F), with a maximum of only 8°C (47°F) and a notable minimum of -16°C (3°F). This month also experiences higher precipitation levels at 158 mm (6.2 in) over approximately 19 days, coupled with a humidity level of 82%. In contrast, May offers a much milder climate, with average temperatures reaching 7°C (44°F) and a maximum of 16°C (61°F). Although May sees slightly less precipitation at 128 mm (5.0 in) over 18 days, its higher temperatures and longer daylight hours make it feel considerably more pleasant. For additional details on February's weather, visit Selfoss weather in February.

In comparing the weather of March and May, it's clear that May brings significantly warmer temperatures, with average highs reaching 16°C (61°F), compared to March's maximum of only 9°C (49°F). While both months experience similar levels of precipitation, with March receiving 121 mm (4.8 in) and May slightly higher at 128 mm (5.0 in), March tends to be colder overall, with a much lower minimum temperature of -15°C (5°F) versus May's -3°C (27°F). Additionally, the humidity remains relatively high in both months, at 83% for May and 85% for March, indicating a damp atmosphere. For more detailed insights into March weather, you can refer to Selfoss weather in March.

In comparing the weather between April and May, we see a notable increase in average temperatures. April experiences a minimum temperature of -12°C (11°F), with an average of 4°C (39°F) and a maximum of 13°C (56°F). In contrast, May's temperatures are milder, ranging from a minimum of -3°C (27°F) to an average of 7°C (44°F) and peaking at 16°C (61°F). While both months receive similar levels of precipitation, with April totaling 140 mm (5.5 in) and May at 128 mm (5.0 in), the number of rainy days remains consistent at 18. Humidity is slightly higher in May at 83%, compared to 81% in April. For a detailed look at April weather specifically, visit Selfoss weather in April.

In May, the weather tends to be cooler, with temperatures ranging from a chilling minimum of -3°C (27°F) to a maximum of 16°C (61°F) and an average of 7°C (44°F). The month is quite wet, featuring 128 mm (5.0 in) of precipitation spread over 18 days, resulting in a high humidity level of 83%. In contrast, June brings a slight warming trend, with minimum temperatures rising to 2°C (37°F) and maximums reaching 19°C (67°F), leading to an average of 9°C (49°F). Additionally, June experiences less rainfall, with 89 mm (3.5 in) over 15 days, coupled with a humidity level of 82%. For a closer look at June's weather in Selfoss, you can visit Selfoss weather in June.

In May, temperatures typically range from a chilly minimum of -3°C (27°F) to a comfortable average of 7°C (44°F), peaking at a maximum of 16°C (61°F). The month is characterized by substantial precipitation, with 128 mm (5.0 in) spread over 18 days and an average humidity of 83%. In contrast, July offers a milder climate, with temperatures starting at a minimum of 4°C (39°F) and reaching an average of 11°C (53°F), and highs soaring to 24°C (76°F). Additionally, rainfall is less frequent in July, totaling 86 mm (3.4 in) over 15 days, while humidity rises slightly to 86%. For more details, you can check Selfoss weather in July.

May and August present notable differences in weather patterns. In May, temperatures range from a chilly -3°C (27°F) at night to a comfortable 16°C (61°F) during the day, with an average temperature of 7°C (44°F). This month also sees significant rainfall, averaging 128 mm (5.0 in) over 18 days, and a high humidity level of 83%. In contrast, August offers milder temperatures, with a minimum of 5°C (41°F), an average of 11°C (52°F), and a maximum of 19°C (66°F). Precipitation is lower in August, at 96 mm (3.8 in) spread over 13 days, and humidity slightly increases to 87%. For more specific details about August weather, you can visit Selfoss weather in August.

May and September in Selfoss exhibit strikingly similar temperature ranges, with both months experiencing maximum temperatures around 16°C (61°F). However, May tends to be slightly warmer overall, averaging 7°C (44°F), compared to September's average of 8°C (47°F). Precipitation is notably higher in September, with 194 mm (7.7 in) over 21 rainy days, compared to May's 128 mm (5.0 in) on 18 days. Additionally, September's humidity is slightly elevated at 87%, while May sits at 83%. For further details, check Selfoss weather in September.

In May, temperatures in the region range from a chilly -3°C (27°F) at night to a comfortable high of 16°C (61°F) during the day, averaging around 7°C (44°F). The month experiences significant precipitation, with 128 mm (5.0 in) falling over 18 days, and humidity levels hover around 83%. In contrast, October brings slightly cooler temperatures, with minimums of -5°C (23°F) and a maximum of 13°C (55°F), averaging 5°C (42°F). While precipitation is somewhat less at 113 mm (4.4 in), it occurs over 16 days, and humidity rises to 88%. For more details on October weather, you can refer to Selfoss weather in October.

The weather in May and November exhibits notable differences in temperature and humidity. In May, temperatures range from a minimum of -3°C (27°F) to a maximum of 16°C (61°F), with an average of 7°C (44°F), while November sees a lower temperature range, with minimums dipping to -8°C (17°F) and maximums reaching only 11°C (52°F), averaging 2°C (35°F). Interestingly, both months receive the same amount of precipitation at 128 mm (5.0 in), but May experiences this over 18 days compared to November's 15 days, contributing to slightly higher humidity in November at 85%, compared to 83% in May. For more detailed information, you can check Selfoss weather in November.

May and December in Selfoss showcase striking contrasts in weather. In May, temperatures fluctuate from a minimum of -3°C (27°F) to a maximum of 16°C (61°F), with an average of 7°C (44°F). The month experiences around 128 mm (5.0 in) of precipitation over 18 days, combined with a humidity level of 83%. In contrast, December features colder temperatures, ranging from a minimum of -11°C (12°F) to a maximum of 9°C (49°F), with an average temperature of 0°C (33°F). The precipitation slightly increases to 137 mm (5.4 in) across 16 days, and humidity remains relatively high at 84%. For a closer look at December weather specifically, you can visit Selfoss weather in December.

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Conclusion: What to Expect From May Weather in Selfoss

As May unfolds in Selfoss, it brings a notable shift in weather compared to the earlier months of the year. With temperatures gradually warming up, the average rises, inviting a more refreshing feel after the chill of winter, yet it still sees fluctuations that can dip to chilly lows. Precipitation remains a common feature, with nearly half the month experiencing rain, contributing to the lush awakening of nature. The persistent humidity creates a unique ambiance, perfect for those eager to explore the stunning landscapes. For a deeper dive into Selfoss' climate patterns and to prepare for your visit, check out Selfoss Climate.