May is one of the warmer months of the year in Post Falls, with average highs near 17.1°C and lows around 5°C (mean 11.1°C). It is about average for rainfall, averaging 63 mm of rainfall and 69% relative humidity across the period.
May is one of the warmer months of the year in Post Falls. Across 45 years of records, the warmest May in Post Falls was 2023 — when the month averaged 15.1°C — while the coldest was 1984 at 7.8°C. Typical May days reach 17.1°C with nights near 5°C. The long-term trend is warming, about 0.3°C per decade.
May is about average for rainfall in Post Falls, averaging 63 mm of rainfall. The wettest May on record was 2020 with 122 mm, while the driest was 1992 at 22 mm.
Relative humidity in Post Falls during May averages 69%. The most humid May was 2022 at 76%, and the least humid was 1992 at 58%.
May receives about 5.9 kWh/m²/day of solar energy in Post Falls. The sunniest Mays were 1992, 2001 and 2009 at 6.7 kWh/m²/day, and the cloudiest was 2022 at 4.8.
Average wind speed in Post Falls during May is 1.1 m/s. The windiest May was 1984 at 1.3 m/s, while the calmest were 2015, 2017 and 2023 at 0.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.6°C | 10.9°C | 10.9°C | 11.5°C | 11.4°C | +0.8°C |
| Avg High | 16.7°C | 16.9°C | 16.9°C | 17.6°C | 17.5°C | +0.8°C |
| Avg Low | 4.5°C | 4.9°C | 4.9°C | 5.4°C | 5.3°C | +0.8°C |
| Avg Rain | 59 mm | 70 mm | 62 mm | 60 mm | 65 mm | +5 mm |
May temperatures in Post Falls have risen by about 1.4°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -3.9°C (1999) to a record high of 32.7°C (1986).
Rainfall in May is about average for rainfall, averaging 63 mm, with a wettest year of 122 mm.
A good time to visit Post Falls
May is a good time to visit Post Falls, with days averaging 17.1°C and nights around 5°C (mean 11.1°C, warmer than Post 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 | 18.4°C | 11.8°C | 5.1°C | 28.7°C | -1.0°C | 49 mm | 69% | 1.1 m/s | 6.1 |
| 2024 | 16.1°C | 10.2°C | 4.2°C | 25.1°C | -2.2°C | 61 mm | 70% | 1.2 m/s | 5.9 |
| 2023 🔥 | 21.2°C | 15.1°C | 9.0°C | 29.6°C | 3.9°C | 55 mm | 71% | 0.9 m/s | 6.3 |
| 2022 | 13.9°C | 8.6°C | 3.4°C | 21.0°C | -2.1°C | 75 mm | 76% | 1.1 m/s | 4.8 |
| 2021 | 18.1°C | 11.6°C | 5.2°C | 26.1°C | 0.2°C | 25 mm | 60% | 1.1 m/s | 6.4 |
| 2020 🌧️ | 17.1°C | 11.1°C | 5.1°C | 28.9°C | -1.8°C | 122 mm | 72% | 1.2 m/s | 5.5 |
| 2019 | 18.8°C | 12.7°C | 6.6°C | 25.1°C | 0.7°C | 64 mm | 68% | 1.1 m/s | 6.3 |
| 2018 | 20.4°C | 14.4°C | 8.4°C | 27.7°C | 1.5°C | 60 mm | 72% | 1 m/s | 6.2 |
| 2017 | 18.0°C | 11.8°C | 5.6°C | 29.5°C | -0.5°C | 53 mm | 68% | 0.9 m/s | 6 |
| 2016 | 18.1°C | 12.2°C | 6.3°C | 25.5°C | 2.3°C | 54 mm | 71% | 1.1 m/s | 6 |
| 2015 | 19.5°C | 13.0°C | 6.5°C | 25.0°C | 0.6°C | 38 mm | 66% | 0.9 m/s | 6.5 |
| 2014 | 17.9°C | 11.7°C | 5.5°C | 24.9°C | -1.1°C | 40 mm | 67% | 1.1 m/s | 6.3 |
| 2013 | 18.1°C | 11.7°C | 5.2°C | 27.1°C | -1.3°C | 44 mm | 67% | 1 m/s | 6 |
| 2012 | 15.8°C | 10.0°C | 4.2°C | 28.6°C | -1.8°C | 57 mm | 67% | 1.2 m/s | 6 |
| 2011 | 14.6°C | 8.9°C | 3.2°C | 20.9°C | -2.0°C | 111 mm | 75% | 1.2 m/s | 5.3 |
| 2010 | 14.5°C | 8.7°C | 2.9°C | 25.1°C | -3.8°C | 80 mm | 70% | 1.1 m/s | 5.4 |
| 2009 | 17.2°C | 10.9°C | 4.6°C | 28.1°C | -1.7°C | 60 mm | 67% | 1.2 m/s | 6.7 |
| 2008 | 17.0°C | 11.0°C | 5.0°C | 26.4°C | -3.2°C | 42 mm | 71% | 1.1 m/s | 5.7 |
| 2007 | 17.7°C | 11.2°C | 4.7°C | 25.9°C | -2.2°C | 40 mm | 67% | 1 m/s | 6.4 |
| 2006 | 18.2°C | 12.0°C | 5.7°C | 31.1°C | -2.8°C | 59 mm | 66% | 1 m/s | 6.2 |
| 2005 | 18.0°C | 12.0°C | 6.0°C | 26.9°C | 0.9°C | 78 mm | 70% | 1 m/s | 5.6 |
| 2004 | 15.9°C | 10.8°C | 5.6°C | 24.1°C | 1.3°C | 107 mm | 72% | 1.1 m/s | 5.2 |
| 2003 | 15.9°C | 10.2°C | 4.5°C | 30.3°C | -2.9°C | 60 mm | 72% | 1.1 m/s | 5.4 |
| 2002 | 15.0°C | 9.3°C | 3.7°C | 24.4°C | -3.2°C | 60 mm | 70% | 1.1 m/s | 5.5 |
| 2001 | 18.7°C | 11.7°C | 4.7°C | 31.1°C | -1.5°C | 38 mm | 59% | 1.2 m/s | 6.7 |
| 2000 | 15.6°C | 10.0°C | 4.3°C | 22.0°C | -1.8°C | 71 mm | 70% | 1.2 m/s | 5.7 |
| 1999 | 14.5°C | 8.5°C | 2.6°C | 27.7°C | -3.9°C | 39 mm | 69% | 1.2 m/s | 6 |
| 1998 | 16.8°C | 11.2°C | 5.6°C | 24.8°C | 0.5°C | 121 mm | 76% | 1.1 m/s | 5.5 |
| 1997 | 18.1°C | 12.2°C | 6.3°C | 26.4°C | -2.5°C | 66 mm | 72% | 1 m/s | 6 |
| 1996 | 13.0°C | 7.9°C | 2.9°C | 21.4°C | -2.3°C | 83 mm | 75% | 1.2 m/s | 5.4 |
| 1995 | 17.5°C | 11.4°C | 5.2°C | 26.9°C | 1.3°C | 44 mm | 69% | 1.1 m/s | 6.4 |
| 1994 | 18.6°C | 12.3°C | 5.9°C | 26.7°C | -1.5°C | 51 mm | 66% | 1.1 m/s | 5.6 |
| 1993 | 20.1°C | 13.9°C | 7.6°C | 29.3°C | 1.1°C | 67 mm | 70% | 1.1 m/s | 6 |
| 1992 | 20.5°C | 13.1°C | 5.7°C | 28.5°C | -1.4°C | 22 mm | 58% | 1.1 m/s | 6.7 |
| 1991 | 15.2°C | 9.4°C | 3.7°C | 20.7°C | -1.2°C | 96 mm | 74% | 1.1 m/s | 5 |
| 1990 | 14.7°C | 9.3°C | 3.9°C | 25.8°C | -2.0°C | 109 mm | 75% | 1.1 m/s | 4.9 |
| 1989 | 15.6°C | 9.9°C | 4.2°C | 23.5°C | 0.2°C | 83 mm | 72% | 1.1 m/s | 5.5 |
| 1988 | 17.3°C | 11.0°C | 4.6°C | 28.6°C | -3.6°C | 59 mm | 67% | 1.1 m/s | 5.5 |
| 1987 | 18.9°C | 12.5°C | 6.2°C | 30.2°C | 0.2°C | 49 mm | 66% | 1.1 m/s | 5.8 |
| 1986 | 17.6°C | 11.4°C | 5.2°C | 32.7°C | -1.3°C | 58 mm | 69% | 1.1 m/s | 5.9 |
| 1985 | 18.1°C | 11.9°C | 5.8°C | 28.8°C | -2.4°C | 50 mm | 67% | 1.1 m/s | 6.1 |
| 1984 ❄️ | 13.2°C | 7.8°C | 2.3°C | 26.2°C | -2.9°C | 87 mm | 74% | 1.3 m/s | 5.3 |
| 1983 | 17.9°C | 11.2°C | 4.5°C | 29.3°C | -1.6°C | 43 mm | 69% | 1.2 m/s | — |
| 1982 | 16.0°C | 9.7°C | 3.4°C | 23.8°C | -3.5°C | 30 mm | 68% | 1.1 m/s | — |
| 1981 | 15.4°C | 9.8°C | 4.2°C | 24.7°C | -1.9°C | 74 mm | 74% | 1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 17.1°C with lows near 5°C (mean 11.1°C), based on 45 years of NASA POWER data.
May averages 63 mm of rainfall in Post Falls, about average for rainfall. The wettest on record was 122 mm in 2020.
The hottest May reached 32.7°C in 1986. The coldest dipped to -3.9°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.4°C. Daytime highs moved from 16.1°C to 17.5°C and overnight lows from 4°C to 5.4°C over the same span.
May is one of the warmer months of the year in Post Falls and about average for rainfall, so plan for around 17.1°C daytime highs and 5°C at night.
Not quite — May is the 8th coolest month in Post Falls, averaging 11.1°C.
For May in Post Falls, pack warm layers and a jacket for chilly mornings, with typical highs of 17.1°C and lows of 5°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 69% — moderately humid.
Average wind speed in May is 1.1 m/s. The windiest May on record averaged 1.3 m/s (1984).
The wettest May on record was 2020 with 122 mm. On average, May sees 63 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 Post 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.
