May is one of the warmer months of the year in Mckinney, with average highs near 28.4°C and lows around 17°C (mean 22.7°C). It is a relatively wet time of year, averaging 132 mm of rainfall and 74% relative humidity across the period.
May is one of the warmer months of the year in Mckinney. Across 45 years of records, the warmest May in Mckinney was 1996 — when the month averaged 27.7°C — while the coldest was 1993 at 20.3°C. Typical May days reach 28.4°C with nights near 17°C. The long-term trend is warming, about 0.3°C per decade.
May is a relatively wet time of year in Mckinney, averaging 132 mm of rainfall. The wettest May on record was 2015 with 399 mm, while the driest was 1996 at 38 mm.
Relative humidity in Mckinney during May averages 74%. The most humid May was 2015 at 85%, and the least humid was 1996 at 55%.
May receives about 5.7 kWh/m²/day of solar energy in Mckinney. The sunniest Mays were 2006 and 2018 at 6.6 kWh/m²/day, and the cloudiest was 2015 at 4.5.
Average wind speed in Mckinney during May is 3.2 m/s. The windiest May was 1996 at 4.7 m/s, while the calmest was 2023 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 22.1°C | 22.3°C | 23.1°C | 22.9°C | 23.2°C | +1.1°C |
| Avg High | 28.0°C | 27.9°C | 28.9°C | 28.7°C | 28.5°C | +0.5°C |
| Avg Low | 16.3°C | 16.8°C | 17.3°C | 17.2°C | 17.9°C | +1.6°C |
| Avg Rain | 169 mm | 129 mm | 97 mm | 129 mm | 147 mm | -22 mm |
May temperatures in Mckinney have risen by about 1.7°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 4°C (2013) to a record high of 40.1°C (1998).
Rainfall in May is a relatively wet time of year, averaging 132 mm, with a wettest year of 399 mm.
One of the best times to visit Mckinney
May is one of the best times to visit Mckinney. Expect days averaging 28.4°C and nights around 17°C (mean 22.7°C) — warmer than Mckinney's yearly average — with higher rainfall (132 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 | 28.4°C | 23.0°C | 17.5°C | 35.7°C | 11.1°C | 127 mm | 75% | 2.7 m/s | 5.6 |
| 2024 | 28.6°C | 24.1°C | 19.5°C | 34.1°C | 13.6°C | 235 mm | 82% | 2.8 m/s | 5.4 |
| 2023 | 28.8°C | 23.4°C | 18.1°C | 34.6°C | 9.6°C | 74 mm | 74% | 2.2 m/s | 5.8 |
| 2022 | 32.4°C | 25.5°C | 18.6°C | 37.4°C | 12.8°C | 89 mm | 64% | 3.9 m/s | 6.1 |
| 2021 | 25.8°C | 21.3°C | 16.9°C | 31.5°C | 9.4°C | 203 mm | 82% | 2.9 m/s | 4.7 |
| 2020 | 27.2°C | 21.9°C | 16.7°C | 31.6°C | 9.2°C | 150 mm | 78% | 3.2 m/s | 6 |
| 2019 | 27.1°C | 22.3°C | 17.5°C | 30.2°C | 10.0°C | 196 mm | 82% | 3.2 m/s | 5.4 |
| 2018 | 31.9°C | 25.7°C | 19.5°C | 37.8°C | 13.4°C | 57 mm | 67% | 2.9 m/s | 6.6 |
| 2017 | 30.2°C | 23.2°C | 16.2°C | 36.5°C | 6.7°C | 42 mm | 62% | 3.4 m/s | 6.4 |
| 2016 | 25.8°C | 21.2°C | 16.6°C | 31.7°C | 8.5°C | 144 mm | 81% | 2.9 m/s | 5.5 |
| 2015 🌧️ | 25.8°C | 21.8°C | 17.9°C | 29.7°C | 13.0°C | 399 mm | 85% | 3.1 m/s | 4.5 |
| 2014 | 29.4°C | 22.8°C | 16.1°C | 35.1°C | 6.4°C | 97 mm | 65% | 3.5 m/s | 6.3 |
| 2013 | 28.1°C | 22.0°C | 16.0°C | 34.1°C | 4.0°C | 101 mm | 69% | 3.6 m/s | 5.6 |
| 2012 | 30.6°C | 24.5°C | 18.4°C | 35.8°C | 14.0°C | 72 mm | 67% | 3.1 m/s | 6.4 |
| 2011 | 29.2°C | 22.7°C | 16.2°C | 37.6°C | 5.6°C | 129 mm | 66% | 4.1 m/s | 5.9 |
| 2010 | 28.9°C | 23.2°C | 17.6°C | 35.3°C | 9.8°C | 55 mm | 72% | 2.8 m/s | 5.9 |
| 2009 | 27.3°C | 21.8°C | 16.3°C | 33.5°C | 10.0°C | 119 mm | 77% | 2.7 m/s | 5.3 |
| 2008 | 28.8°C | 22.7°C | 16.6°C | 34.7°C | 7.5°C | 85 mm | 71% | 3.4 m/s | 5.9 |
| 2007 | 26.5°C | 22.3°C | 18.1°C | 30.2°C | 11.6°C | 190 mm | 82% | 2.7 m/s | 5 |
| 2006 | 30.9°C | 24.1°C | 17.4°C | 37.4°C | 10.5°C | 46 mm | 64% | 3.3 m/s | 6.6 |
| 2005 | 29.2°C | 23.1°C | 16.9°C | 38.9°C | 6.6°C | 78 mm | 68% | 2.8 m/s | 5.6 |
| 2004 | 29.0°C | 23.3°C | 17.5°C | 35.4°C | 6.9°C | 51 mm | 74% | 3.8 m/s | 5.7 |
| 2003 | 31.4°C | 24.9°C | 18.3°C | 39.2°C | 14.0°C | 83 mm | 67% | 3 m/s | 5.4 |
| 2002 | 27.0°C | 21.5°C | 15.9°C | 33.4°C | 8.5°C | 120 mm | 76% | 3.3 m/s | 5.6 |
| 2001 | 27.7°C | 22.6°C | 17.5°C | 31.7°C | 9.5°C | 114 mm | 78% | 3.1 m/s | 6.1 |
| 2000 | 30.7°C | 24.5°C | 18.2°C | 37.4°C | 10.0°C | 86 mm | 68% | 4 m/s | 6 |
| 1999 | 28.0°C | 22.2°C | 16.5°C | 32.2°C | 9.4°C | 164 mm | 74% | 3.1 m/s | 5.8 |
| 1998 | 32.5°C | 25.3°C | 18.1°C | 40.1°C | 12.2°C | 41 mm | 63% | 3.1 m/s | 6.4 |
| 1997 | 25.7°C | 20.4°C | 15.2°C | 32.1°C | 8.2°C | 102 mm | 79% | 3 m/s | 5.8 |
| 1996 🔥 | 35.0°C | 27.7°C | 20.4°C | 39.8°C | 10.0°C | 38 mm | 55% | 4.7 m/s | 6.1 |
| 1995 | 26.4°C | 21.3°C | 16.1°C | 32.2°C | 7.9°C | 198 mm | 81% | 3.2 m/s | 5.2 |
| 1994 | 26.4°C | 21.3°C | 16.2°C | 31.1°C | 5.7°C | 168 mm | 81% | 2.5 m/s | 5.6 |
| 1993 ❄️ | 25.7°C | 20.3°C | 15.0°C | 30.8°C | 8.1°C | 78 mm | 80% | 3.4 m/s | 5.4 |
| 1992 | 25.1°C | 20.5°C | 15.9°C | 32.3°C | 8.2°C | 152 mm | 81% | 2.7 m/s | 5.1 |
| 1991 | 27.7°C | 23.2°C | 18.7°C | 32.1°C | 9.0°C | 127 mm | 82% | 2.9 m/s | 5.5 |
| 1990 | 26.5°C | 21.1°C | 15.8°C | 31.8°C | 7.8°C | 220 mm | 81% | 3.7 m/s | 5.6 |
| 1989 | 27.8°C | 22.4°C | 17.1°C | 32.6°C | 10.6°C | 247 mm | 79% | 3.5 m/s | 5.8 |
| 1988 | 30.2°C | 22.9°C | 15.5°C | 34.7°C | 9.3°C | 82 mm | 57% | 3.2 m/s | 6.3 |
| 1987 | 28.5°C | 23.6°C | 18.7°C | 33.4°C | 14.7°C | 205 mm | 77% | 2.8 m/s | 5.7 |
| 1986 | 26.4°C | 21.5°C | 16.5°C | 30.5°C | 10.2°C | 185 mm | 80% | 3.3 m/s | 5.2 |
| 1985 | 27.3°C | 21.7°C | 16.1°C | 34.6°C | 10.7°C | 97 mm | 76% | 3 m/s | 6.3 |
| 1984 | 31.2°C | 23.9°C | 16.7°C | 36.3°C | 9.3°C | 75 mm | 61% | 3.6 m/s | 5.9 |
| 1983 | 27.0°C | 20.6°C | 14.3°C | 31.9°C | 8.5°C | 153 mm | 71% | 3.3 m/s | — |
| 1982 | 26.4°C | 21.6°C | 16.7°C | 31.5°C | 7.8°C | 293 mm | 82% | 3.2 m/s | — |
| 1981 | 26.9°C | 21.1°C | 15.3°C | 31.8°C | 6.8°C | 184 mm | 74% | 3.5 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 28.4°C with lows near 17°C (mean 22.7°C), based on 45 years of NASA POWER data.
May averages 132 mm of rainfall in Mckinney, a relatively wet time of year. The wettest on record was 399 mm in 2015.
The hottest May reached 40.1°C in 1998. The coldest dipped to 4°C in 2013.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.7°C. Daytime highs moved from 27.8°C to 28.8°C and overnight lows from 15.8°C to 18.1°C over the same span.
May is one of the warmer months of the year in Mckinney and a relatively wet time of year, so plan for around 28.4°C daytime highs and 17°C at night.
Not quite — May is the 8th coolest month in Mckinney, averaging 22.7°C.
For May in Mckinney, pack light layers you can adjust through the day, with typical highs of 28.4°C and lows of 17°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 74% — moderately humid.
Average wind speed in May is 3.2 m/s. The windiest May on record averaged 4.7 m/s (1996).
The wettest May on record was 2015 with 399 mm. On average, May sees 132 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 Mckinney 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.
