May is one of the warmer months of the year in Phoenix, with average highs near 34.1°C and lows around 16.9°C (mean 25.5°C). It is one of the drier months, averaging 6 mm of rainfall and 23% relative humidity across the period.
May is one of the warmer months of the year in Phoenix. Across 45 years of records, the warmest May in Phoenix was 1997 — when the month averaged 28.7°C — while the coldest was 1995 at 21.7°C. Typical May days reach 34.1°C with nights near 16.9°C. The long-term trend is warming, about 0.2°C per decade.
May is one of the drier months in Phoenix, averaging 6 mm of rainfall. The wettest May on record was 1992 with 42 mm, while the driest were 2010, 2013 and 2014, among others at 0 mm.
Relative humidity in Phoenix during May averages 23%. The most humid May was 1992 at 44%, and the least humid was 2002 at 14%.
May receives about 8 kWh/m²/day of solar energy in Phoenix. The sunniest Mays were 2012, 2021 and 2022 at 8.5 kWh/m²/day, and the cloudiest were 1988 and 1992 at 7.1.
Average wind speed in Phoenix during May is 2.2 m/s. The windiest Mays were 1990, 1991 and 2011 at 2.5 m/s, while the calmest were 1994, 2005 and 2009 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.3°C | 24.6°C | 26.6°C | 24.9°C | 26.4°C | +1.1°C |
| Avg High | 34.1°C | 33.1°C | 35.2°C | 33.4°C | 35.2°C | +1.1°C |
| Avg Low | 16.5°C | 16.1°C | 17.9°C | 16.6°C | 17.7°C | +1.2°C |
| Avg Rain | 6 mm | 8 mm | 6 mm | 6 mm | 2 mm | -3 mm |
May temperatures in Phoenix have risen by about 0.9°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 4.9°C (1988) to a record high of 44.2°C (2020).
Rainfall in May is one of the drier months, averaging 6 mm, with a wettest year of 42 mm.
One of the best times to visit Phoenix
May is one of the best times to visit Phoenix. Expect days averaging 34.1°C and nights around 16.9°C (mean 25.5°C) — warmer than Phoenix's yearly average — with low rainfall (6 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 34.6°C | 26.2°C | 17.7°C | 40.4°C | 11.4°C | 5 mm | 20% | 2.2 m/s | 7.7 |
| 2024 | 34.4°C | 25.7°C | 16.9°C | 40.2°C | 10.6°C | 0 mm | 22% | 2 m/s | 8.3 |
| 2023 | 34.1°C | 25.8°C | 17.6°C | 38.6°C | 11.5°C | 6 mm | 27% | 2.1 m/s | 8.2 |
| 2022 | 36.0°C | 26.6°C | 17.3°C | 40.7°C | 11.0°C | 1 mm | 15% | 2.3 m/s | 8.5 |
| 2021 | 35.4°C | 26.5°C | 17.6°C | 38.7°C | 11.8°C | 1 mm | 14% | 2.2 m/s | 8.5 |
| 2020 | 36.7°C | 27.8°C | 18.9°C | 44.2°C | 13.4°C | 1 mm | 22% | 2.2 m/s | 8.4 |
| 2019 | 29.8°C | 22.4°C | 15.1°C | 36.8°C | 10.5°C | 9 mm | 32% | 2.1 m/s | 7.8 |
| 2018 | 35.4°C | 26.9°C | 18.4°C | 40.8°C | 10.9°C | 2 mm | 18% | 2.2 m/s | 8.3 |
| 2017 | 34.3°C | 25.8°C | 17.3°C | 41.5°C | 11.7°C | 4 mm | 22% | 2.3 m/s | 8.2 |
| 2016 | 33.0°C | 24.8°C | 16.7°C | 39.6°C | 11.9°C | 5 mm | 24% | 2.2 m/s | 8.2 |
| 2015 | 30.9°C | 23.5°C | 16.1°C | 40.1°C | 9.6°C | 37 mm | 32% | 2 m/s | 7.7 |
| 2014 | 34.7°C | 26.1°C | 17.5°C | 41.3°C | 9.8°C | 0 mm | 17% | 2.4 m/s | 8.1 |
| 2013 | 35.0°C | 26.2°C | 17.5°C | 38.6°C | 14.0°C | 0 mm | 19% | 2.4 m/s | 8.2 |
| 2012 | 36.3°C | 27.1°C | 18.0°C | 42.9°C | 13.6°C | 2 mm | 15% | 2.3 m/s | 8.5 |
| 2011 | 32.4°C | 23.4°C | 14.5°C | 38.4°C | 9.1°C | 3 mm | 19% | 2.5 m/s | 8.4 |
| 2010 | 32.0°C | 23.2°C | 14.4°C | 37.4°C | 7.8°C | 0 mm | 24% | 2.2 m/s | 8.4 |
| 2009 | 36.2°C | 28.0°C | 19.8°C | 41.1°C | 16.6°C | 13 mm | 25% | 1.9 m/s | 7.8 |
| 2008 | 31.6°C | 23.3°C | 15.0°C | 42.4°C | 9.3°C | 25 mm | 26% | 2.2 m/s | 7.9 |
| 2007 | 35.2°C | 26.8°C | 18.4°C | 41.0°C | 10.6°C | 4 mm | 20% | 2.1 m/s | 8.3 |
| 2006 | 35.8°C | 27.2°C | 18.7°C | 40.0°C | 14.3°C | 1 mm | 16% | 2.2 m/s | 8.2 |
| 2005 | 34.0°C | 25.7°C | 17.4°C | 42.7°C | 10.7°C | 2 mm | 30% | 1.9 m/s | 8.1 |
| 2004 | 35.7°C | 26.7°C | 17.6°C | 39.4°C | 12.7°C | 1 mm | 17% | 2.3 m/s | 8.4 |
| 2003 | 34.7°C | 26.2°C | 17.7°C | 43.1°C | 9.5°C | 1 mm | 22% | 2.1 m/s | 8 |
| 2002 | 34.7°C | 25.8°C | 16.9°C | 43.4°C | 11.6°C | 0 mm | 14% | 2.2 m/s | 8.4 |
| 2001 | 37.3°C | 28.2°C | 19.0°C | 42.7°C | 9.7°C | 5 mm | 21% | 2.2 m/s | 8.3 |
| 2000 | 37.2°C | 27.9°C | 18.7°C | 44.0°C | 11.6°C | 3 mm | 16% | 2.4 m/s | 8.3 |
| 1999 | 33.5°C | 24.8°C | 16.0°C | 40.7°C | 7.7°C | 0 mm | 20% | 2.4 m/s | 8.2 |
| 1998 | 30.6°C | 22.4°C | 14.3°C | 36.4°C | 9.6°C | 2 mm | 34% | 2.1 m/s | 7.8 |
| 1997 🔥 | 37.4°C | 28.7°C | 20.0°C | 42.7°C | 13.1°C | 4 mm | 20% | 2.2 m/s | 7.8 |
| 1996 | 36.0°C | 26.6°C | 17.3°C | 43.2°C | 13.9°C | 0 mm | 16% | 2.4 m/s | 8.3 |
| 1995 ❄️ | 29.7°C | 21.7°C | 13.6°C | 37.5°C | 7.9°C | 3 mm | 34% | 2.2 m/s | 7.5 |
| 1994 | 32.6°C | 24.3°C | 15.9°C | 39.0°C | 11.0°C | 17 mm | 28% | 1.9 m/s | 7.2 |
| 1993 | 33.6°C | 25.0°C | 16.5°C | 38.1°C | 10.7°C | 5 mm | 36% | 2.2 m/s | 8 |
| 1992 🌧️ | 32.9°C | 25.4°C | 17.9°C | 38.2°C | 13.4°C | 42 mm | 44% | 2 m/s | 7.1 |
| 1991 | 31.9°C | 22.8°C | 13.7°C | 38.2°C | 8.6°C | 1 mm | 26% | 2.5 m/s | 7.3 |
| 1990 | 32.8°C | 24.1°C | 15.4°C | 37.6°C | 10.2°C | 5 mm | 21% | 2.5 m/s | 7.5 |
| 1989 | 35.0°C | 26.0°C | 17.0°C | 42.7°C | 12.1°C | 3 mm | 19% | 2.4 m/s | 7.7 |
| 1988 | 33.4°C | 24.6°C | 15.8°C | 39.8°C | 4.9°C | 0 mm | 24% | 2.4 m/s | 7.1 |
| 1987 | 32.8°C | 24.9°C | 17.1°C | 36.5°C | 9.9°C | 8 mm | 29% | 2.2 m/s | 7.6 |
| 1986 | 34.8°C | 25.7°C | 16.5°C | 40.8°C | 8.9°C | 3 mm | 20% | 2.3 m/s | 7.8 |
| 1985 | 34.6°C | 26.0°C | 17.4°C | 39.2°C | 11.2°C | 0 mm | 24% | 2.3 m/s | 7.7 |
| 1984 | 38.0°C | 28.5°C | 19.1°C | 44.0°C | 11.2°C | 5 mm | 20% | 2.3 m/s | 7.4 |
| 1983 | 33.0°C | 23.7°C | 14.3°C | 42.7°C | 8.5°C | 0 mm | 31% | 2.3 m/s | — |
| 1982 | 32.7°C | 23.9°C | 15.0°C | 38.0°C | 8.8°C | 22 mm | 29% | 2.2 m/s | — |
| 1981 | 32.9°C | 24.4°C | 15.9°C | 37.2°C | 10.9°C | 9 mm | 23% | 2.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 34.1°C with lows near 16.9°C (mean 25.5°C), based on 45 years of NASA POWER data.
May averages 6 mm of rainfall in Phoenix, one of the drier months. The wettest on record was 42 mm in 1992.
The hottest May reached 44.2°C in 2020. The coldest dipped to 4.9°C in 1988.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.9°C. Daytime highs moved from 34.2°C to 34.9°C and overnight lows from 16.3°C to 17.4°C over the same span.
May is one of the warmer months of the year in Phoenix and one of the drier months, so plan for around 34.1°C daytime highs and 16.9°C at night.
Not quite — May is the 8th coolest month in Phoenix, averaging 25.5°C.
For May in Phoenix, pack light, breathable clothing and sun protection, with typical highs of 34.1°C and lows of 16.9°C.
Relative humidity in May averages 23% — relatively dry.
Average wind speed in May is 2.2 m/s. The windiest May on record averaged 2.5 m/s (1990).
The wettest May on record was 1992 with 42 mm. On average, May sees 6 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Phoenix behaves each May, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for May specifically, along with year-by-year records and how the month has changed over the decades.
