Phoenix Weather in May
May brings the start of 100-degree Fahrenheit (over 38 °Celsius) weather to Phoenix, Arizona. May is also sunnier and drier than most other months.
This page gives detailed information on the typical May temperature, precipitation, sun, humidity, wind and storms for Phoenix. The weather measurements are averages based on climate data gathered at Phoenix Sky Harbor International Airport, located near the city center.
Temperature
| 95 °F | May average high | 35 °C |
| 70 °F | May average low | 21 °C |
| 24 days | 90 °F max. or more (32 °C) |
| 18 days | 70 °F min. or less (21 °C) |
Nearly every day in May warms to over 80 degrees Fahrenheit (27 degrees Celsius) in Phoenix. The city averages 9 days this month when the thermometer spikes into the 100s °F (over 38 °C).
The thermometer dips to 60 °F (16 °C) or below on an average 2 nights. But May does not normally get as cold as 50 °F (10 °C).
Rain
| 0.1 in | total precipitation | 3 mm |
| 1 day | of rain |
Most years, Phoenix gets no precipitation at all in May. About one in four years receives just 0.1 inches (2 mm) or more of rain.
Sun
| 93 % | sunshine |
| 21 days | clear skies |
The sun's rays reach the ground in Phoenix during 93 percent of daylight hours on average in May, for a total of 401 hours in the month. Typically on 21 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in May at Phoenix lasts for 13 hours and 54 minutes a day on average. The shortest day of the month is the 1st with 13 hours and 32 minutes of daylight. By the end of the month, the days have lengthened to 14:13 from sunrise to sunset. These durations can vary by a minute or two from year to year.
Humidity
| 22 % | May average humidity |
The relative humidity in Phoenix during May usually peaks at 35 percent in the morning then drops to 13 percent by late afternoon.
| Local Time | 2 am | 5 am | 8 am | 11 am | 2 pm | 5 pm | 8 pm | 11 pm |
| Humidity % | 29 | 35 | 27 | 18 | 14 | 13 | 16 | 22 |
Wind
| 7.0 mph | May wind speed average | 11.3 kph |
May is windier than most other months in Phoenix.
Storms
| 0 days | rainfall of 0.5 inches (13 mm) or more |
| 1 day | with thunderstorms in May |
May is one of the least stormy months for Phoenix.
Reference
The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.