May Weather in St. John's, Canada

Last updated: April 22, 2025

In May, St. John's, Canada emerges from the chill of winter, offering a refreshing spring climate characterized by a maximum temperature of 20°C (68°F) and an average of 5°C (41°F). Despite this warming trend, minimum temperatures can dip to -3°C (27°F), reminding residents of the lingering coolness. With an average precipitation amount of 80 mm (3.1 in) spread across 12 days, May is often marked by damp conditions, elevated by a significant humidity level of 90%. This month paints a picture of transitional weather, blending the vibrancy of spring with the remnants of winter's grasp.

May Temperature in St. John's

In May, St. John's, Canada, begins to shed the last remnants of winter as temperatures rise markedly. With minimums around -3°C (27°F) and average highs reaching a pleasant 20°C (68°F), the city starts to buzz with life as the days beautifully transition into spring. Compared to the preceding months, where chilly temperatures lingered, May marks a significant warming trend, bringing a sense of renewal. The average temperature of 5°C (41°F) signals a fresh start, inviting both locals and visitors to enjoy the blossoming landscapes. As the chill of winter gives way to milder, sunnier days, this month sets the perfect stage for outdoor adventures and celebrations in the vibrant city.

May Weather in St. John's: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in St. John's, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec282629364150586256474033
Data source: Temperature data for St. John's 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 St. John's

In St. John's, Canada, May brings a notable shift in precipitation, with an average of 80 mm (3.1 in) over 12 rainy days. This marks a significant decrease from the wettest months earlier in the year, as January through April consistently recorded higher rainfall, ranging from 100 mm to 113 mm. The trend suggests a gradual easing of spring's wet embrace, leading into the summer months. After May, precipitation begins to slightly rise again in June to 86 mm (3.4 in), hinting at a pattern where wetter conditions oscillate throughout the year. As the landscape transitions from spring's showers to summer's milder rains, May serves as a pivotal point, balancing warmth and moisture for the burgeoning season ahead.

May Precipitation Trends in St. John's

The chart displays monthly precipitation patterns in St. John's, 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.
JanFebMarAprMayJunJulAugSepOctNovDec11310210010380861006910797108134
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in St. John's

As the seasons shift in St. John's, Canada, May heralds a noticeable increase in humidity, reaching 90%—a significant jump from the 88% in April. This rising trend continues into the summer, with humidity peaking at 94% in July. The gradual escalation of moisture in the air signifies the approach of warmer months and an environment rich in vitality. Visitors can expect the air to feel increasingly dense as it transitions from the cooler, drier winter months, where humidity starts at 83% in January and only climbs throughout spring. May sets the stage for the summer's sultriness, laying the groundwork for a lush and vibrant setting.

May Average Humidity in St. John's

This chart illustrates the average monthly humidity levels in St. John's, 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.
JanFebMarAprMayJunJulAugSepOctNovDec83%84%85%88%91%91%94%93%90%87%84%83%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in St. John's

As May rolls into St. John's, Canada, residents and visitors alike should be aware that the UV Index soars to an impressive 8, marking the beginning of a season where sun safety becomes paramount. With a “very high” exposure category, the risk of harm from unprotected sun exposure drastically increases, cutting burn time to a mere 15 minutes. This trend continues into June and July, where the UV Index peaks at 10 and 9 respectively, before tapering off in the fall. The gradual rise from 2 in January to 8 in May illustrates a clear shift towards more intense sun during the warmer months. As you plan your outdoor activities, remember to protect your skin and stay informed about the St. John's UV Index to ensure a safe and enjoyable experience under the sun.

Maximum UV Index Levels in St. John's for May

The chart shows the monthly maximum UV Index (UVI) for St. John's 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.
JanFebMarAprMayJunJulAugSepOctNovDec2357810987421
Data source: St. John's 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 St. John's

As the vibrant month of May unfolds in St. John's, Canada, residents eagerly welcome an impressive 280 hours of sunshine, marking a delightful peak in sunlight hours for the year. This significant increase from the previous months is a clear indication of spring's embrace, following a gradual rise from 208 hours in April. The trend continues as the city transitions into summer, with June and July offering similarly generous doses of sunlight, peaking at 306 hours in August. This pattern showcases a captivating shift from the limited daylight of winter months, where January recorded a mere 88 hours. The sunshine not only brightens the skies but also uplifts spirits, inviting outdoor adventures and community gatherings as the warmer days approach.

Monthly Sunshine Duration in St. John's: May Highlighted

The May sunshine duration represents the total number of hours St. John's 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.
JanFebMarAprMayJunJulAugSepOctNovDec88h127h207h208h280h270h286h306h251h175h138h103h
Data source: St. John's May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in St. John's During May

In St. John's, Canada, the likelihood of experiencing sunny weather in May shows a promising uptick, with a 32% chance of sunshine. This marks a notable improvement compared to the dismal winter months, where January and February boast only 17% and 18% chances, respectively. The month of March begins to hint at brighter days ahead, rising to 36%, while April remains relatively low at 19%. As spring fully unfolds in May, the likelihood of sunshine starts to resemble the early summer months, which hover around 33% in June and 25% in July. This trend indicates that as the seasons progress, residents and visitors of St. John's can look forward to an increasing opportunity to soak up some rays in May, making it a delightful time to enjoy the scenery.

Percentage of Sunny Days in May in St. John's

The chart illustrates the percentage of sunny days in St. John's 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 St. John's experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec17%18%36%19%32%33%25%29%38%20%30%26%
Data source: St. John's May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in St. John's in May

As spring blossoms into summer, St. John's, Canada, experiences a remarkable shift in daylight duration. Starting in January with just 8 hours of sunlight, the days gradually lengthen to 10 hours in February and 11 hours in March as winter gives way to early spring. By April, the daylight extends to 13 hours, setting the stage for May's peak at an invigorating 15 hours. This generous daylight persists through June and July, allowing residents to savor the warm evenings. As late summer transitions into early autumn, daylight begins to wane, dropping to 14 hours in August and further to 12 hours in September. Ultimately, by October, daylight decreases to 10 hours, heralding the approach of winter once again, with the cycle repeating as the year closes with 9 hours in November and returning to 8 hours in December. This cyclical dance of daylight in St. John's paints a vivid picture of the changing seasons.

Average Daylight Hours in St. John's for May

The chart illustrates the variation in daylight duration in St. John's throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 55m10h 16m11h 56m13h 39m15h 7m15h 52m15h 28m14h 9m12h 30m10h 48m9h 17m8h 30m
Data source: St. John's daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in St. John's

In May, the winds in St. John's, Canada, exhibit a gentle decline, with an average speed of 5.4 m/s (12 mph). This marks a slight decrease from April's 5.6 m/s, suggesting a transition to the calmness of summer. Interestingly, while the wind speeds peak in the earlier months, notably reaching 7.2 m/s in December, there appears to be a consistent trend of diminishing wind through spring and the onset of summer. By June, the average dips further to 5.0 m/s, reflecting a seasonal shift that locals may appreciate as they enjoy outdoor activities. Overall, May serves as a pivotal month, bridging the brisk spring breezes with the softer winds of the approaching summer.

Average May Wind Speed in St. John's

The chart displays monthly wind speed patterns in St. John's, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.86.76.25.65.4 m/s5.04.75.25.15.96.07.2
Data source: St. John's May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in St. John's Compares to Other Months

The weather in St. John's 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 St. John's and find detailed weather information for every month.

When comparing the weather in May and January, there are notable differences in both temperature and precipitation. In May, temperatures range from a minimum of -3°C (27°F) to a pleasant maximum of 20°C (68°F), with an average of 5°C (41°F). This month sees about 80 mm (3.1 in) of precipitation over 12 days and a high humidity level of 90%. In contrast, January is much colder, with temperatures dipping as low as -14°C (7°F) and averaging -2°C (29°F), peaking at 12°C (54°F). It experiences slightly higher precipitation at 113 mm (4.5 in) over 13 days, along with a humidity of 83%. For more detailed information about January's weather, you can visit St. John's weather in January.

When comparing the weather in May and February, it's clear that May brings a significant warming trend. In May, temperatures can range from a chilly -3°C (27°F) to a pleasant max of 20°C (68°F), with an average of 5°C (41°F). In contrast, February is much colder, with temperatures ranging from -16°C (3°F) to a maximum of only 10°C (50°F) and an average of -3°C (26°F). While both months see similar precipitation days—12 in each—February has slightly higher precipitation at 102 mm (4.0 in) compared to May's 80 mm (3.1 in). Additionally, May experiences a higher humidity level of 90%, compared to February's 84%. For a more detailed look at February, visit St. John's weather in February.

In comparing the weather between March and May, it's evident that May brings a significant warming trend. While March experiences a chilly average temperature of -2°C (29°F) with minimum lows of -14°C (8°F), May sees temperatures rise to an average of 5°C (41°F), peaking at a pleasant 20°C (68°F). Despite May's warmer conditions, it does bring along 80 mm (3.1 in) of precipitation over 12 days, compared to March's slightly higher 100 mm (3.9 in) across 13 days. Humidity levels also differ slightly, with May at a humid 90% and March at 85%. For more detailed insights, you can explore St. John's weather in March.

In comparing the weather between April and May, we notice a transition towards milder temperatures. May typically has a minimum temperature of -3°C (27°F) compared to April's cooler minimum of -6°C (22°F), and its maximum reaches a more comfortable 20°C (68°F) versus April's 15°C (60°F). The average temperature in May also rises to 5°C (41°F), which is an improvement over April's 2°C (36°F). However, April experiences slightly more precipitation at 103 mm (4.0 in) over 14 days, compared to May's 80 mm (3.1 in) on 12 days. Despite the increased rainfall in April, May's humidity level is higher at 90%, reflecting the change in season. For a closer look, you can check St. John's weather in April.

May and June exhibit a noticeable shift in weather patterns. In May, temperatures range from a minimum of -3°C (27°F) to a maximum of 20°C (68°F), with an average of 5°C (41°F). The month sees about 80 mm (3.1 in) of precipitation over 12 days, accompanied by a high humidity level of 90%. By contrast, June temperatures rise, with a minimum of 0°C (33°F), an average of 10°C (51°F), and a maximum of 24°C (75°F). While precipitation slightly increases to 86 mm (3.4 in) over the same 12 days, humidity remains comparable at 91%. For a closer look at June weather specifics, check out St. John's weather in June.

In May, the weather in St. John's is characterized by cooler temperatures, with a minimum of -3°C (27°F) and an average of 5°C (41°F), while July sees a significant increase, with minimum temperatures rising to 6°C (43°F) and an average of 15°C (58°F). July also experiences higher maximum temperatures, reaching up to 25°C (76°F), compared to May’s max of 20°C (68°F). While both months receive considerable rainfall, May has 80 mm (3.1 in) over 12 days, whereas July sees slightly more precipitation at 100 mm (3.9 in) across 10 days. Additionally, humidity levels are notably high in both months, with May at 90% and July at 94%. For more detailed insights on July weather, visit St. John's weather in July.

In comparing the weather between May and August, we notice distinct differences. May tends to be cooler, with temperatures ranging from a minimum of -3°C (27°F) to a maximum of 20°C (68°F) and an average of 5°C (41°F). It also experiences higher precipitation, averaging 80 mm (3.1 in) over about 12 rainy days, coupled with a humidity level of 90%. In contrast, August offers warmer temperatures, with a minimum of 8°C (46°F), an average of 17°C (62°F), and a maximum of 27°C (80°F). The month is slightly drier, with 69 mm (2.7 in) of precipitation spread over around 10 days and a higher humidity of 93%. For a detailed look at what to expect, you can check out St. John's weather in August.

May and September in St. John's showcase distinct differences in weather patterns. In May, temperatures range from a brisk -3°C (27°F) to a mild 20°C (68°F), with an average of 5°C (41°F). The month experiences about 80 mm (3.1 in) of precipitation over approximately 12 days, while the humidity remains high at 90%. In contrast, September offers a warmer climate, with temperatures ranging from a minimum of 4°C (39°F) to a pleasant maximum of 24°C (75°F), averaging around 13°C (56°F). The amount of rainfall also increases slightly, reaching 107 mm (4.2 in) over 11 days. Despite the uptick in precipitation, the humidity remains consistently high at 90%. For more details, check out St. John's weather in September.

In May, temperatures range from a chilly minimum of -3°C (27°F) to a pleasant maximum of 20°C (68°F), with an average of 5°C (41°F). The month sees around 80 mm (3.1 in) of precipitation over 12 days, accompanied by high humidity at 90%. In contrast, October experiences slightly milder conditions, with temperatures starting at 0°C (32°F) and reaching a maximum of 22°C (72°F), averaging 8°C (48°F). October also has a bit more precipitation, totaling 97 mm (3.8 in) over the same number of days, but with a lower humidity level of 87%. For more details on October weather, you can check St. John's weather in October.

May and November in St. John's exhibit distinct weather patterns, reflecting the transition between spring and late autumn. In May, temperatures range from a minimum of -3°C (27°F) to a maximum of 20°C (68°F), with an average of 5°C (41°F), while November sees slightly cooler temperatures with a minimum of -6°C (22°F), an average of 4°C (40°F), and a maximum of 16°C (62°F). Precipitation is more significant in November, totaling 108 mm (4.3 in) over 13 days, compared to May's 80 mm (3.1 in) over 12 days. Humidity levels are high in both months, but May experiences slightly higher humidity at 90%, while November's humidity stands at 84%. For more details, check out St. John's weather in November.

May and December in St. John's present two distinct weather experiences. May sees a wider temperature range, with minimums around -3°C (27°F) and maximums reaching up to 20°C (68°F), while averaging 5°C (41°F). In contrast, December is colder, with averages hovering around 0°C (33°F) and maximums capping at 15°C (59°F), alongside lower humidity at 83% compared to May's 90%. Additionally, December experiences more precipitation, with 133 mm (5.3 in) over 16 days, compared to May’s 80 mm (3.1 in) over 12 days. For more details on December weather, you can visit St. John's weather in December.

Compare St. John's's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in St. John's

As May unfolds in St. John's, the weather begins to transition from the lingering chill of winter to the promise of warmer days. With average temperatures hovering around 5°C, the city experiences its first real signs of spring, distinguished by a notable increase in humidity at 90%. While the 80 mm of precipitation over approximately 12 days ensures the lushness of the landscape, these wetter conditions are a sharp contrast to the drier and cooler months preceding it. Thus, May serves as a pivotal month, bridging St. John's still-cool springtime with the summer warmth to come. For a deeper dive into the overarching trends of St. John's weather, explore St. John's Climate.