May Weather in Phoenix, United States

Last updated: February 24, 2025

In Phoenix, United States, May marks the transition to intense summer heat, with maximum temperatures soaring to 43°C (109°F) while maintaining a comfortable average of 28°C (82°F). The month showcases the dry desert climate, with an astonishing precipitation amount of only 2 mm (0.1 in) and absolutely no days of rain, highlighting the arid conditions typical of this period. A moderate humidity level of 40% adds to the warmth, making it crucial for residents and visitors to stay hydrated and protect themselves from the sun's rays during outdoor activities.

May Temperature in Phoenix

In Phoenix, May marks a significant transition towards the sweltering summer, where temperatures begin to soar. The month starts with a comfortable minimum of 13°C (55°F) and an inviting average of 28°C (82°F), making it a great time for outdoor activities. However, as the days progress, the sun’s intensity increases, peaking with maximum highs of a sizzling 43°C (109°F). This trend indicates a clear shift from the mildness of spring to the heat characteristic of southern Arizona. The warmth in May sets the stage for the even hotter months ahead, signaling that summer is just around the corner.

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

The chart illustrates May temperature patterns in Phoenix, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec545764758292959489756555
Data source: Temperature data for Phoenix 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 Phoenix

In Phoenix, United States, May typically marks a transition into the dry heat of summer, as evidenced by a mere 2 mm (0.1 in) of precipitation recorded this month. Surprisingly, not a single day of rain was noted in May, continuing a trend observed in the preceding month, April, which also saw no rainfall. This pattern underscores the distinct seasonal shift characteristic of the region, where the early part of the year experiences higher precipitation levels—January through March collectively average about 25 mm (1.0 in) each month—before quickly dwindling to minimal amounts by late spring. The dry conditions set the stage for the influx of monsoon rains that typically begins in July, where precipitation levels sharply rise to 37 mm (1.4 in), breathing life back into the desert landscape.

May Precipitation Trends in Phoenix

The chart displays monthly precipitation patterns in Phoenix, 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.
JanFebMarAprMayJunJulAugSepOctNovDec253729122373927262123
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Phoenix

As May arrives in Phoenix, the city enjoys a significant drop in humidity, plunging to 40%. This marks a stark contrast to the wetter winter months, where humidity levels hover around 76% in January and 79% in February. The transition from spring to early summer showcases a discernible trend: as temperatures rise, humidity steadily decreases, reaching its annual low of 33% by June. This gradual decline, with April already dipping to 55%, sets the stage for the dry heat that characterizes Phoenix's summer months. Interestingly, as the season progresses into late summer, humidity begins to creep back up, peaking at 48% in August before the cycle resets in fall. Overall, May stands out as a pivotal point where the dry, warm climate becomes more pronounced, inviting residents and visitors alike to relish the sun-soaked days ahead.

May Average Humidity in Phoenix

This chart illustrates the average monthly humidity levels in Phoenix, 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.
JanFebMarAprMayJunJulAugSepOctNovDec76%79%67%55%40%33%34%48%64%67%77%82%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Phoenix

In May, Phoenix experiences its most intense sun exposure of the year, with a staggering UV Index of 11, categorizing it as extreme. This significant increase from April’s already high UV level reflects a trend of escalating solar intensity as summer approaches. With a burn time of just 10 minutes, it’s crucial for residents and visitors to take proactive measures to protect their skin. Following this pattern, the UV Index remains high through June and July, showcasing the region's relentless sun. For those planning outdoor activities, understanding the May UV Index can help ensure safety under the blazing Phoenix sun. For more detailed information, visit Phoenix UV Index.

Maximum UV Index Levels in Phoenix for May

The chart shows the monthly maximum UV Index (UVI) for Phoenix 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.
JanFebMarAprMayJunJulAugSepOctNovDec469101112111110754
Data source: Phoenix 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 Phoenix

May in Phoenix welcomes an impressive 373 hours of sunshine, marking it as one of the sunniest months of the year. Following the steady increase from 195 hours in January to 331 hours in April, May shines brighter than its predecessor, revealing an upward trend as the days grow longer and warmer. This peak sunshine duration sets the stage for the almost equally radiant June, which brings 375 hours of sunlight. Overall, the consistent rise in daylight hours throughout spring leads to an inviting atmosphere, encouraging outdoor activities and creating a vibrant, sun-soaked community spirit. As the desert blooms in full splendor, May serves as a delightful prelude to the summer heat, making it an ideal time to soak in the energizing rays of the Arizona sun.

Monthly Sunshine Duration in Phoenix: May Highlighted

The May sunshine duration represents the total number of hours Phoenix 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.
JanFebMarAprMayJunJulAugSepOctNovDec195h241h309h331h373h375h361h346h315h297h258h240h
Data source: Phoenix May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Phoenix During May

As spring gives way to summer in Phoenix, the likelihood of sun-soaked days reaches a stunning 90% in May. This marks a significant leap from the 76% chance observed in April, indicating a seamless transition into the sun-drenched months ahead. The pattern is clear: as winter fades, so does the cloud cover, with May standing out as one of the sunniest months of the year. While June still promises ample sunshine at 72%, the vibrant and warm allure of May positions it as the ideal time for outdoor activities amidst clear blue skies. Embrace the sunshine, because in May, Phoenix truly shines!

Percentage of Sunny Days in May in Phoenix

The chart illustrates the percentage of sunny days in Phoenix 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 Phoenix experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec60%73%73%76%90%72%36%59%70%76%71%55%
Data source: Phoenix May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Phoenix in May

As May unfolds in Phoenix, residents can enjoy a wholesome 13 hours of daylight, marking a significant continuation of spring’s warm embrace. This month, daylight duration mirrors that of April, showcasing an upward trend from the deep winter months of January and February, which both offered only 10 hours. This gradual increase peaks in June with 14 hours, revealing a steady rise throughout the spring that enhances outdoor activities and social gatherings. The radiant energy of May invites everyone to take advantage of longer evenings, while also hinting at the imminent summer months, where daylight persists just a little longer before tapering off in the fall.

Average Daylight Hours in Phoenix for May

The chart illustrates the variation in daylight duration in Phoenix throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 12m10h 59m11h 59m13h 1m13h 53m14h 19m14h 5m13h 19m12h 19m11h 18m10h 24m9h 57m
Data source: Phoenix daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Phoenix

In Phoenix, the winds of May present a gentle shift in the breezy pattern that emerges throughout the year. With an average wind speed of 2.6 m/s (6 mph), May shows a slight decrease from April's 2.8 m/s (6 mph), indicating a stabilization before the summer heat intensifies. Interestingly, this month aligns with winds that are usually at their peak for this time, as it transitions from the more variable spring months into the drier conditions of summer. Following a trend of gradual fluctuation, the return to 2.8 m/s (6 mph) in June suggests a resurgence in wind, likely influenced by the surrounding desert landscape. Overall, May exemplifies a moment of calm within the warming environment, setting the stage for the hotter months ahead.

Average May Wind Speed in Phoenix

The chart displays monthly wind speed patterns in Phoenix, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.22.42.72.82.6 m/s2.82.11.91.82.42.11.9
Data source: Phoenix May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Phoenix Compares to Other Months

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

In May, Phoenix experiences warm and dry conditions, with average temperatures reaching a comfortable 28°C (82°F) and highs soaring to an impressive 43°C (109°F). The humidity is relatively low at 40%, and there's effectively no precipitation, making it an ideal time for outdoor activities. In contrast, January brings cooler weather, with average temperatures around 12°C (54°F) and lows dipping to a chilly -1°C (30°F). The month has an average of 25 mm (1.0 in) of precipitation over 4 days, and the humidity increases to 76%, giving the month a distinctly wetter and cooler feel. For more detailed insights into January weather, you can check out Phoenix weather in January.

May and February present two distinct weather profiles in terms of temperature and precipitation. In May, temperatures range from a minimum of 13°C (55°F) to a scorching maximum of 43°C (109°F), with an average of 28°C (82°F). The month is characterized by very little rainfall, totaling only 2 mm (0.1 in), and a low humidity level of 40%. In contrast, February experiences much cooler temperatures, with a minimum of 1°C (33°F) and a maximum of 29°C (84°F), averaging 14°C (57°F). It is also a wetter month, receiving 37 mm (1.4 in) of precipitation over three days and showing higher humidity at 79%. For more information on February's climate, you can check Phoenix weather in February.

When comparing the weather in March and May, a stark contrast emerges. May experiences significantly warmer temperatures, with a minimum of 13°C (55°F) and an average high reaching 43°C (109°F), while March sees cooler temperatures, starting at a minimum of 4°C (39°F) and a maximum of 35°C (95°F). Additionally, May boasts dry conditions with only 2 mm of precipitation over zero rainfall days, whereas March encounters more moisture, with 29 mm of rain spread over three days, contributing to a higher humidity level of 67%. For more detailed insights on March weather, you can visit Phoenix weather in March.

In comparison to April, May experiences significantly warmer temperatures, with average highs reaching up to 43°C (109°F) compared to April's maximum of 39°C (103°F). While both months report minimal precipitation and no rainy days, May boasts a lower humidity level at 40%, making the heat feel more intense than in April, where humidity sits at 55%. For more information on the weather dynamics during this time, you can check out Phoenix weather in April.

In comparing the weather of May and June, it’s evident that June experiences higher temperatures across the board. In May, the minimum temperature is a comfortable 13°C (55°F), while June starts at a warmer 19°C (66°F). The average temperature also escalates from 28°C (82°F) in May to a sweltering 34°C (93°F) in June. The maximum temperatures soar even higher, reaching 43°C (109°F) in May and peaking at 48°C (119°F) in June. Interestingly, both months see minimal precipitation, with only 2 mm (0.1 in) recorded and no rainy days. Additionally, June shows a lower humidity level at 33% compared to May’s 40%. For more detailed insights, check out Phoenix weather in June.

May and July in Phoenix showcase a stark contrast in weather patterns. In May, the temperatures range from a minimum of 13°C (55°F) to a maximum of 43°C (109°F), with an average of 28°C (82°F) and little to no precipitation, creating a dry environment with a humidity level of 40%. In contrast, July sees much warmer conditions, with minimum temperatures starting at 23°C (74°F) and soaring up to a maximum of 47°C (118°F), averaging around 35°C (95°F). Additionally, July experiences more rainfall, with approximately 37 mm (1.4 in) over about 6 days, and a slightly lower humidity level of 34%. This comparison highlights the intensifying heat and occasional moisture that characterizes the peak of summer in the region. For more details, you can check Phoenix weather in July.

May and August in Phoenix showcase distinct differences in weather patterns. In May, temperatures fluctuate between a mild 13°C (55°F) at night and a scorching 43°C (109°F) during the day, while the average temperature sits at a comfortable 28°C (82°F). The month experiences very little rainfall, with only 2 mm (0.1 in) recorded over none of the days, and humidity levels around 40%.

In contrast, August is significantly warmer, with minimum temperatures starting at 22°C (73°F) and soaring to a maximum of 47°C (116°F), averaging 35°C (95°F). This month also brings more moisture, with precipitation totaling 39 mm (1.5 in) spread over approximately 5 days and a higher humidity level of 48%. For more detailed information, check out Phoenix weather in August.

Comparing the weather in May and September reveals some notable differences. In May, temperatures range from a minimum of 13°C (55°F) to a maximum of 43°C (109°F), with an average of 28°C (82°F) and little to no precipitation, making it a dry month with a humidity level of 40%. In contrast, September offers slightly higher average temperatures at 32°C (89°F), with maximums reaching up to 45°C (113°F), and is accompanied by more humidity at 64%. Additionally, September experiences some rainfall, with 27 mm (1.1 in) over three days, indicating a shift toward wetter conditions compared to the dry May climate. For more detailed insights, check out Phoenix weather in September.

May weather tends to be quite warm, with temperatures ranging from a minimum of 13°C (55°F) to a blistering maximum of 43°C (109°F), while averaging around 28°C (82°F). In contrast, October sees a drop in temperatures, with a minimum of 7°C (45°F) and an average of 24°C (76°F), peaking at 41°C (105°F). While May enjoys dry conditions with virtually no precipitation and low humidity at 40%, October experiences increased humidity at 67% and a modest amount of rainfall, totaling 26 mm (1.0 in) over two days. For more detailed insights on the October weather, check out Phoenix weather in October.

May and November present a striking contrast in weather patterns. May boasts a significant temperature range, with minimums around 13°C (55°F) and scorching maximums peaking at 43°C (109°F), making it a hot and dry month with only 2 mm of precipitation. The humidity levels are relatively low at 40%, contributing to the arid feel. In contrast, November cools down considerably, featuring minimum temperatures of 5°C (41°F) and a more moderate average of 18°C (66°F). This month also sees increased precipitation, totaling 21 mm (0.8 in) over the course of just one day, along with a noticeable rise in humidity to 77%. For more details about November weather, check out Phoenix weather in November.

In May, the weather is typically hot and dry, with minimum temperatures around 13°C (55°F) and maximums soaring up to 43°C (109°F), while averaging around 28°C (82°F) and experiencing almost no precipitation. The humidity remains relatively low at 40%. In contrast, December brings much cooler temperatures, ranging from a chilly minimum of 0°C (32°F) to a mild maximum of 28°C (83°F), and an average of 13°C (55°F). Additionally, December sees more precipitation, averaging 23 mm (0.9 in) over about 4 days, with humidity levels significantly higher at 82%. For more details on winter weather conditions, visit Phoenix weather in December.

Compare Phoenix's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Phoenix

As May unfolds in Phoenix, residents experience a dramatic shift in temperature, transitioning to warmer days that set the stage for summer. With an average of 28°C (82°F), May offers a delightful warmth, but it's the peaks reaching up to 43°C (109°F) that truly highlight the season's intensity. Unlike the earlier months, May boasts zero precipitation days, emphasizing the arid conditions typical of this time of year. Coupled with a humidity level around 40%, the environment feels increasingly dry. For those curious about how these conditions fit into the broader weather patterns, more insights can be found at Phoenix Climate.