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May Weather in Phoenix, United States

Last updated: June 24, 2025

In May, the average temperature in Phoenix, United States hovers around 14°C (57°F). Expect a range of conditions, with minimums dropping to -1°C (31°F) and peaks soaring to 32°C (90°F). Rainfall is fairly frequent, with 119 mm (4.7 in) expected over approximately 14 days, while the air maintains an average humidity of 82%.

May Temperature in Phoenix

In May in Phoenix, the average temperature is 14°C (57°F). Maximums can reach 32°C (90°F), while minimums can drop as low as -1°C (31°F). Travelers should be prepared for a range of temperatures, so packing layers is advisable.

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. In Phoenix, May typically has an average temperature of 14°C (57°F), with highs reaching up to 32°C (90°F) and lows dropping to around -1°C (31°F).
JanFebMarAprMayJunJulAugSepOctNovDec272935455766737165554032
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 in May, the precipitation amount is 119 mm (4.7 in) over the course of 14 days.

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. In Phoenix, May typically receives around 119 mm (4.7 inches) of precipitation spread over approximately 14 days.
JanFebMarAprMayJunJulAugSepOctNovDec97999112211910017512487170115114
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Phoenix

In Phoenix in May, humidity is 82%. With an average temperature of 14°C (57°F), this humidity feels like a thick blanket enveloping you, making outdoor activities uncomfortable and travel more challenging due to the heavy, damp air.

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, helping you understand how conditions vary by season. In May, average humidity in Phoenix is approximately 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%90%87%88%82%79%78%76%78%84%89%86%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Phoenix

In Phoenix in May, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Phoenix.

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. In May, the maximum UV index in Phoenix typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3468910997632
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.

How May Weather in Phoenix Compares to Other Months

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

This table compares monthly weather conditions in Phoenix, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (27°F)97 mm (3.8 inches)90%moderate
February Weather-2°C (29°F)98 mm (3.9 inches)90%moderate
March Weather1°C (35°F)91 mm (3.6 inches)87%high
April Weather7°C (46°F)122 mm (4.8 inches)88%very high
May Weather14°C (57°F)119 mm (4.7 inches)82%very high
June Weather19°C (67°F)100 mm (3.9 inches)79%very high
July Weather23°C (73°F)175 mm (6.9 inches)78%very high
August Weather22°C (72°F)124 mm (4.9 inches)76%very high
September Weather18°C (65°F)87 mm (3.4 inches)78%high
October Weather13°C (55°F)170 mm (6.7 inches)84%high
November Weather5°C (41°F)115 mm (4.5 inches)89%moderate
December Weather0°C (33°F)114 mm (4.5 inches)86%low

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