May is one of the warmer months of the year in Twin Falls, with average highs near 20.3°C and lows around 5.7°C (mean 13°C). It is a relatively wet time of year, averaging 42 mm of rainfall and 52% relative humidity across the period.
May is one of the warmer months of the year in Twin Falls. Across 45 years of records, the warmest May in Twin Falls was 1992 — when the month averaged 17.2°C — while the coldest was 2010 at 8.5°C. Typical May days reach 20.3°C with nights near 5.7°C. The long-term May temperature trend is broadly flat.
May is a relatively wet time of year in Twin Falls, averaging 42 mm of rainfall. The wettest May on record was 2005 with 110 mm, while the driest was 1992 at 4 mm.
Relative humidity in Twin Falls during May averages 52%. The most humid May was 2011 at 65%, and the least humid was 1992 at 33%.
May receives about 6.6 kWh/m²/day of solar energy in Twin Falls. The sunniest Mays were 2001 and 2007 at 7.5 kWh/m²/day, and the cloudiest were 2015 and 2019 at 5.7.
Average wind speed in Twin Falls during May is 2.8 m/s. The windiest May was 2024 at 3.4 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 | 12.6°C | 13.0°C | 13.7°C | 12.4°C | 13.4°C | +0.8°C |
| Avg High | 20.1°C | 20.2°C | 21.2°C | 19.3°C | 20.6°C | +0.5°C |
| Avg Low | 5.2°C | 5.8°C | 6.2°C | 5.4°C | 6.1°C | +0.9°C |
| Avg Rain | 32 mm | 50 mm | 37 mm | 53 mm | 36 mm | +4 mm |
May temperatures in Twin Falls have risen by about 1.2°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -4.5°C (2002) to a record high of 37.9°C (2003).
Rainfall in May is a relatively wet time of year, averaging 42 mm, with a wettest year of 110 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.2°C per decade, narrowing the gap between day and night.
A good time to visit Twin Falls
May is a good time to visit Twin Falls, with days averaging 20.3°C and nights around 5.7°C (mean 13°C, warmer than Twin Falls's yearly average) and moderate rainfall. August and July are marginally more temperate, but May still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 23.2°C | 15.5°C | 7.8°C | 34.9°C | -0.1°C | 22 mm | 47% | 2.9 m/s | 7.1 |
| 2024 | 18.6°C | 11.5°C | 4.4°C | 30.7°C | -1.0°C | 30 mm | 53% | 3.4 m/s | 7.1 |
| 2023 | 21.7°C | 15.1°C | 8.4°C | 30.6°C | 1.0°C | 54 mm | 57% | 2.2 m/s | 6.3 |
| 2022 | 18.1°C | 11.2°C | 4.3°C | 32.0°C | -1.8°C | 51 mm | 54% | 3.2 m/s | 6.3 |
| 2021 | 20.8°C | 13.3°C | 5.8°C | 30.3°C | 0.7°C | 18 mm | 45% | 2.8 m/s | 7.2 |
| 2020 | 21.2°C | 13.5°C | 5.9°C | 34.9°C | -0.9°C | 39 mm | 49% | 2.7 m/s | 6.8 |
| 2019 | 18.7°C | 12.3°C | 5.9°C | 27.6°C | -2.5°C | 85 mm | 59% | 2.5 m/s | 5.7 |
| 2018 | 21.2°C | 14.6°C | 8.0°C | 30.2°C | 1.8°C | 59 mm | 60% | 2.3 m/s | 6.1 |
| 2017 | 19.9°C | 12.6°C | 5.2°C | 31.4°C | -1.4°C | 27 mm | 59% | 2.6 m/s | 7.2 |
| 2016 | 19.2°C | 12.5°C | 5.7°C | 27.9°C | 0.5°C | 50 mm | 58% | 2.6 m/s | 6.6 |
| 2015 | 20.8°C | 14.1°C | 7.4°C | 29.4°C | 1.9°C | 90 mm | 55% | 2.3 m/s | 5.7 |
| 2014 | 21.2°C | 13.7°C | 6.2°C | 30.1°C | 0.7°C | 39 mm | 51% | 2.6 m/s | 7.1 |
| 2013 | 20.8°C | 13.5°C | 6.2°C | 31.7°C | -4.0°C | 18 mm | 49% | 2.7 m/s | 6.8 |
| 2012 | 20.8°C | 12.8°C | 4.8°C | 33.1°C | -3.4°C | 27 mm | 46% | 3.1 m/s | 7.2 |
| 2011 | 15.7°C | 9.3°C | 2.9°C | 25.4°C | -3.3°C | 74 mm | 65% | 2.9 m/s | 6 |
| 2010 ❄️ | 15.0°C | 8.5°C | 1.9°C | 25.0°C | -2.9°C | 57 mm | 56% | 3.2 m/s | 5.9 |
| 2009 | 21.3°C | 13.7°C | 6.0°C | 32.7°C | -3.3°C | 30 mm | 52% | 2.4 m/s | 7 |
| 2008 | 19.8°C | 12.4°C | 5.0°C | 30.5°C | -3.5°C | 31 mm | 51% | 2.8 m/s | 6.7 |
| 2007 | 22.6°C | 14.8°C | 6.9°C | 31.4°C | -1.8°C | 12 mm | 43% | 2.8 m/s | 7.5 |
| 2006 | 21.7°C | 14.2°C | 6.6°C | 31.6°C | -1.8°C | 35 mm | 52% | 2.5 m/s | 7.2 |
| 2005 🌧️ | 20.1°C | 13.0°C | 5.9°C | 28.4°C | 0.8°C | 110 mm | 61% | 2.7 m/s | 6.1 |
| 2004 | 20.0°C | 13.0°C | 6.0°C | 29.4°C | -0.3°C | 50 mm | 51% | 3.1 m/s | 6.6 |
| 2003 | 20.9°C | 13.5°C | 6.0°C | 37.9°C | -2.9°C | 34 mm | 51% | 2.5 m/s | 6.8 |
| 2002 | 20.3°C | 12.6°C | 4.8°C | 32.7°C | -4.5°C | 22 mm | 46% | 3 m/s | 6.9 |
| 2001 | 23.9°C | 15.6°C | 7.3°C | 34.0°C | -1.2°C | 10 mm | 38% | 3.1 m/s | 7.5 |
| 2000 | 21.8°C | 14.4°C | 7.0°C | 30.0°C | -2.1°C | 32 mm | 48% | 3 m/s | 6.7 |
| 1999 | 18.1°C | 11.0°C | 3.8°C | 29.5°C | -3.9°C | 41 mm | 54% | 2.9 m/s | 6.8 |
| 1998 | 18.1°C | 11.6°C | 5.1°C | 26.5°C | -1.4°C | 104 mm | 61% | 2.6 m/s | 6 |
| 1997 | 22.8°C | 15.2°C | 7.6°C | 33.2°C | -3.9°C | 23 mm | 51% | 2.4 m/s | 7.1 |
| 1996 | 18.2°C | 11.4°C | 4.6°C | 27.2°C | -1.9°C | 65 mm | 57% | 2.8 m/s | 6.2 |
| 1995 | 17.0°C | 10.8°C | 4.5°C | 25.0°C | -0.3°C | 80 mm | 64% | 2.5 m/s | 6 |
| 1994 | 22.7°C | 15.2°C | 7.7°C | 30.2°C | 0.7°C | 45 mm | 50% | 2.4 m/s | 6.1 |
| 1993 | 22.7°C | 15.1°C | 7.4°C | 29.4°C | -0.6°C | 30 mm | 54% | 2.9 m/s | 6.8 |
| 1992 🔥 | 25.2°C | 17.2°C | 9.2°C | 31.6°C | 2.1°C | 4 mm | 33% | 2.7 m/s | 7.4 |
| 1991 | 18.1°C | 10.9°C | 3.7°C | 26.3°C | 0.1°C | 55 mm | 54% | 3 m/s | 6 |
| 1990 | 18.7°C | 11.4°C | 4.1°C | 27.3°C | -2.7°C | 49 mm | 51% | 2.9 m/s | 6.7 |
| 1989 | 19.6°C | 12.1°C | 4.6°C | 28.6°C | -2.0°C | 22 mm | 51% | 2.8 m/s | 6.7 |
| 1988 | 21.0°C | 13.2°C | 5.4°C | 32.3°C | -4.1°C | 48 mm | 46% | 3.1 m/s | 6.8 |
| 1987 | 22.4°C | 15.2°C | 7.9°C | 32.1°C | 0.6°C | 55 mm | 47% | 2.4 m/s | 6.5 |
| 1986 | 20.3°C | 12.6°C | 5.0°C | 32.2°C | -2.5°C | 29 mm | 50% | 2.9 m/s | 6.9 |
| 1985 | 22.5°C | 14.5°C | 6.4°C | 30.9°C | -2.6°C | 31 mm | 44% | 2.8 m/s | 6.7 |
| 1984 | 19.3°C | 11.6°C | 4.0°C | 33.3°C | -3.2°C | 18 mm | 55% | 3.1 m/s | 6.4 |
| 1983 | 18.0°C | 11.3°C | 4.5°C | 31.8°C | -3.4°C | 26 mm | 56% | 2.8 m/s | — |
| 1982 | 18.6°C | 11.3°C | 3.9°C | 26.9°C | -2.5°C | 25 mm | 53% | 2.9 m/s | — |
| 1981 | 18.8°C | 11.7°C | 4.7°C | 29.8°C | -1.1°C | 33 mm | 52% | 3.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 20.3°C with lows near 5.7°C (mean 13°C), based on 45 years of NASA POWER data.
May averages 42 mm of rainfall in Twin Falls, a relatively wet time of year. The wettest on record was 110 mm in 2005.
The hottest May reached 37.9°C in 2003. The coldest dipped to -4.5°C in 2002.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.2°C. Daytime highs moved from 19.4°C to 20.5°C and overnight lows from 4.7°C to 6.1°C over the same span.
May is one of the warmer months of the year in Twin Falls and a relatively wet time of year, so plan for around 20.3°C daytime highs and 5.7°C at night.
Not quite — May is the 8th coolest month in Twin Falls, averaging 13°C.
For May in Twin Falls, pack warm layers and a jacket for chilly mornings, with typical highs of 20.3°C and lows of 5.7°C.
Relative humidity in May averages 52% — relatively dry.
Average wind speed in May is 2.8 m/s. The windiest May on record averaged 3.4 m/s (2024).
The wettest May on record was 2005 with 110 mm. On average, May sees 42 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 Twin Falls 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.
