May is one of the warmer months of the year in Keller, with average highs near 29.3°C and lows around 16.8°C (mean 23.1°C). It is a relatively wet time of year, averaging 127 mm of rainfall and 70% relative humidity across the period.
May is one of the warmer months of the year in Keller. Across 45 years of records, the warmest May in Keller was 1996 — when the month averaged 28°C — while the coldest was 1997 at 20.5°C. Typical May days reach 29.3°C with nights near 16.8°C. The long-term trend is warming, about 0.2°C per decade.
May is a relatively wet time of year in Keller, averaging 127 mm of rainfall. The wettest May on record was 2015 with 387 mm, while the driest was 1996 at 38 mm.
Relative humidity in Keller during May averages 70%. The most humid May was 2015 at 85%, and the least humid was 1996 at 52%.
May receives about 6 kWh/m²/day of solar energy in Keller. The sunniest May was 2006 at 7.1 kWh/m²/day, and the cloudiest was 2015 at 4.6.
Average wind speed in Keller 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 | 22.5°C | 22.7°C | 23.5°C | 23.2°C | 23.3°C | +0.8°C |
| Avg High | 29.0°C | 29.0°C | 29.9°C | 29.5°C | 29.0°C | 0°C |
| Avg Low | 16.1°C | 16.5°C | 17.0°C | 16.9°C | 17.5°C | +1.4°C |
| Avg Rain | 166 mm | 124 mm | 90 mm | 125 mm | 139 mm | -27 mm |
May temperatures in Keller have risen by about 1.1°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 3.6°C (2011) to a record high of 41.7°C (1998).
Rainfall in May is a relatively wet time of year, averaging 127 mm, with a wettest year of 387 mm.
One of the best times to visit Keller
May is one of the best times to visit Keller. Expect days averaging 29.3°C and nights around 16.8°C (mean 23.1°C) — warmer than Keller's yearly average — with higher rainfall (127 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 | 28.5°C | 22.7°C | 16.9°C | 36.5°C | 10.0°C | 128 mm | 74% | 2.5 m/s | 5.8 |
| 2024 | 29.1°C | 24.0°C | 18.9°C | 36.4°C | 12.9°C | 199 mm | 80% | 2.8 m/s | 5.3 |
| 2023 | 28.8°C | 23.3°C | 17.7°C | 37.7°C | 10.1°C | 98 mm | 73% | 2.2 m/s | 5.9 |
| 2022 | 33.2°C | 25.9°C | 18.6°C | 39.2°C | 10.8°C | 74 mm | 60% | 3.9 m/s | 6.4 |
| 2021 | 25.7°C | 21.1°C | 16.4°C | 31.3°C | 8.8°C | 186 mm | 82% | 2.8 m/s | 4.7 |
| 2020 | 28.4°C | 22.5°C | 16.6°C | 36.3°C | 8.9°C | 145 mm | 73% | 3.2 m/s | 6.5 |
| 2019 | 27.1°C | 22.0°C | 16.9°C | 30.5°C | 9.2°C | 202 mm | 81% | 3.2 m/s | 5.6 |
| 2018 | 32.7°C | 26.0°C | 19.3°C | 39.1°C | 12.6°C | 65 mm | 65% | 2.9 m/s | 6.8 |
| 2017 | 30.6°C | 23.3°C | 16.0°C | 38.9°C | 6.5°C | 46 mm | 59% | 3.3 m/s | 6.3 |
| 2016 | 26.3°C | 21.2°C | 16.1°C | 33.1°C | 8.0°C | 168 mm | 79% | 2.8 m/s | 5.6 |
| 2015 🌧️ | 25.7°C | 21.5°C | 17.3°C | 30.1°C | 12.3°C | 387 mm | 85% | 3 m/s | 4.6 |
| 2014 | 30.8°C | 23.4°C | 16.1°C | 36.7°C | 5.8°C | 75 mm | 60% | 3.5 m/s | 6.5 |
| 2013 | 29.1°C | 22.5°C | 15.8°C | 36.1°C | 3.6°C | 77 mm | 65% | 3.7 m/s | 5.8 |
| 2012 | 32.2°C | 25.4°C | 18.6°C | 38.6°C | 13.2°C | 62 mm | 61% | 3.3 m/s | 6.6 |
| 2011 | 30.2°C | 22.9°C | 15.7°C | 39.6°C | 3.6°C | 103 mm | 63% | 4.1 m/s | 6.2 |
| 2010 | 30.4°C | 24.0°C | 17.6°C | 36.5°C | 9.3°C | 69 mm | 65% | 2.9 m/s | 6.1 |
| 2009 | 28.4°C | 22.2°C | 16.0°C | 35.4°C | 9.5°C | 91 mm | 73% | 2.7 m/s | 5.8 |
| 2008 | 30.7°C | 23.6°C | 16.6°C | 37.6°C | 7.1°C | 72 mm | 64% | 3.6 m/s | 6.4 |
| 2007 | 26.7°C | 22.3°C | 17.8°C | 29.8°C | 11.5°C | 182 mm | 81% | 2.7 m/s | 4.9 |
| 2006 | 31.1°C | 24.1°C | 17.1°C | 37.6°C | 9.5°C | 60 mm | 63% | 3.2 m/s | 7.1 |
| 2005 | 30.0°C | 23.4°C | 16.8°C | 39.8°C | 6.5°C | 80 mm | 64% | 2.9 m/s | 5.6 |
| 2004 | 29.9°C | 23.5°C | 17.1°C | 36.2°C | 6.5°C | 53 mm | 70% | 3.8 m/s | 5.9 |
| 2003 | 32.6°C | 25.3°C | 17.9°C | 40.0°C | 13.9°C | 84 mm | 61% | 3 m/s | 5.5 |
| 2002 | 28.1°C | 21.8°C | 15.5°C | 36.4°C | 8.2°C | 116 mm | 71% | 3.4 m/s | 6 |
| 2001 | 29.5°C | 23.4°C | 17.3°C | 35.4°C | 9.2°C | 100 mm | 72% | 3.2 m/s | 6.4 |
| 2000 | 32.4°C | 25.2°C | 18.0°C | 40.5°C | 10.0°C | 64 mm | 63% | 4 m/s | 6.4 |
| 1999 | 29.4°C | 22.8°C | 16.3°C | 33.8°C | 9.0°C | 148 mm | 69% | 3.2 m/s | 5.9 |
| 1998 | 34.9°C | 26.6°C | 18.2°C | 41.7°C | 11.8°C | 45 mm | 54% | 3.3 m/s | 6.8 |
| 1997 ❄️ | 26.2°C | 20.5°C | 14.7°C | 34.1°C | 7.3°C | 118 mm | 77% | 2.9 m/s | 6 |
| 1996 🔥 | 35.8°C | 28.0°C | 20.1°C | 40.7°C | 9.5°C | 38 mm | 52% | 4.7 m/s | 6.5 |
| 1995 | 27.2°C | 21.4°C | 15.6°C | 33.5°C | 8.3°C | 179 mm | 76% | 3.2 m/s | 5.6 |
| 1994 | 27.0°C | 21.4°C | 15.9°C | 32.4°C | 5.0°C | 177 mm | 80% | 2.4 m/s | 5.6 |
| 1993 | 27.2°C | 20.9°C | 14.7°C | 33.7°C | 7.5°C | 76 mm | 74% | 3.4 m/s | 6 |
| 1992 | 26.5°C | 21.0°C | 15.6°C | 36.5°C | 8.0°C | 148 mm | 76% | 2.8 m/s | 5.2 |
| 1991 | 29.0°C | 23.7°C | 18.5°C | 34.4°C | 9.8°C | 124 mm | 77% | 3.1 m/s | 5.5 |
| 1990 | 27.1°C | 21.1°C | 15.1°C | 32.8°C | 6.9°C | 184 mm | 78% | 3.6 m/s | 6.1 |
| 1989 | 28.4°C | 22.5°C | 16.6°C | 34.6°C | 11.1°C | 268 mm | 77% | 3.4 m/s | 6.2 |
| 1988 | 31.0°C | 23.3°C | 15.6°C | 35.8°C | 9.0°C | 107 mm | 52% | 3.3 m/s | 6.6 |
| 1987 | 29.5°C | 23.9°C | 18.4°C | 34.8°C | 14.9°C | 201 mm | 73% | 2.9 m/s | 5.5 |
| 1986 | 27.3°C | 21.7°C | 16.1°C | 33.1°C | 9.3°C | 180 mm | 78% | 3.3 m/s | 5.2 |
| 1985 | 29.0°C | 22.4°C | 15.8°C | 39.2°C | 9.8°C | 90 mm | 70% | 3 m/s | 6.4 |
| 1984 | 32.6°C | 24.6°C | 16.7°C | 39.2°C | 8.9°C | 60 mm | 55% | 3.5 m/s | 6.4 |
| 1983 | 28.2°C | 21.3°C | 14.3°C | 34.8°C | 8.7°C | 146 mm | 66% | 3.4 m/s | — |
| 1982 | 26.8°C | 21.6°C | 16.4°C | 32.3°C | 6.7°C | 286 mm | 80% | 3.3 m/s | — |
| 1981 | 27.9°C | 21.5°C | 15.1°C | 34.2°C | 8.1°C | 154 mm | 71% | 3.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 29.3°C with lows near 16.8°C (mean 23.1°C), based on 45 years of NASA POWER data.
May averages 127 mm of rainfall in Keller, a relatively wet time of year. The wettest on record was 387 mm in 2015.
The hottest May reached 41.7°C in 1998. The coldest dipped to 3.6°C in 2011.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.1°C. Daytime highs moved from 28.9°C to 29.1°C and overnight lows from 15.7°C to 17.7°C over the same span.
May is one of the warmer months of the year in Keller and a relatively wet time of year, so plan for around 29.3°C daytime highs and 16.8°C at night.
Not quite — May is the 8th coolest month in Keller, averaging 23.1°C.
For May in Keller, pack light layers you can adjust through the day, with typical highs of 29.3°C and lows of 16.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 70% — 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 387 mm. On average, May sees 127 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 Keller 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.
