August is one of the warmer months of the year in Idaho Falls, with average highs near 28.3°C and lows around 12.5°C (mean 20.4°C). It is one of the drier months, averaging 28 mm of rainfall and 41% relative humidity across the period.
August is one of the warmer months of the year in Idaho Falls. Across 45 years of records, the warmest August in Idaho Falls was 2001 — when the month averaged 23°C — while the coldest was 1993 at 16.8°C. Typical August days reach 28.3°C with nights near 12.5°C. The long-term trend is warming, about 0.2°C per decade.
August is one of the drier months in Idaho Falls, averaging 28 mm of rainfall. The wettest August on record was 2014 with 106 mm, while the driest was 1985 at 4 mm.
Relative humidity in Idaho Falls during August averages 41%. The most humid August was 2014 at 59%, and the least humid was 1988 at 25%.
August receives about 6.4 kWh/m²/day of solar energy in Idaho Falls. The sunniest August was 1988 at 7 kWh/m²/day, and the cloudiest was 2014 at 5.4.
Average wind speed in Idaho Falls during August is 2.2 m/s. The windiest Augusts were 1985 and 2000 at 2.7 m/s, while the calmest were 2014 and 2017 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 19.9°C | 20.2°C | 20.7°C | 20.4°C | 21.2°C | +1.3°C |
| Avg High | 27.9°C | 28.2°C | 28.8°C | 28.2°C | 28.6°C | +0.7°C |
| Avg Low | 11.8°C | 12.2°C | 12.6°C | 12.5°C | 13.7°C | +1.9°C |
| Avg Rain | 24 mm | 26 mm | 23 mm | 29 mm | 45 mm | +21 mm |
August temperatures in Idaho Falls have risen by about 0.8°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 1.2°C (1992) to a record high of 37.3°C (2000).
Rainfall in August is one of the drier months, averaging 28 mm, with a wettest year of 106 mm.
One of the best times to visit Idaho Falls
August is one of the best times to visit Idaho Falls. Expect days averaging 28.3°C and nights around 12.5°C (mean 20.4°C) — warmer than Idaho Falls's yearly average — with low rainfall (28 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 | 29.6°C | 21.9°C | 14.3°C | 34.9°C | 9.7°C | 37 mm | 38% | 2.2 m/s | 6.2 |
| 2024 | 28.9°C | 21.1°C | 13.2°C | 35.6°C | 7.1°C | 39 mm | 43% | 2.2 m/s | 6.3 |
| 2023 | 26.9°C | 20.1°C | 13.3°C | 33.5°C | 6.9°C | 70 mm | 56% | 2.2 m/s | 5.9 |
| 2022 | 29.6°C | 22.4°C | 15.1°C | 35.0°C | 11.0°C | 54 mm | 47% | 1.9 m/s | 6.2 |
| 2021 | 26.7°C | 19.3°C | 11.9°C | 34.3°C | 6.3°C | 64 mm | 47% | 2.1 m/s | 5.7 |
| 2020 | 30.0°C | 22.1°C | 14.1°C | 34.9°C | 5.4°C | 8 mm | 39% | 2.2 m/s | 6.7 |
| 2019 | 29.0°C | 21.2°C | 13.4°C | 33.5°C | 8.1°C | 11 mm | 42% | 2.2 m/s | 6.9 |
| 2018 | 27.6°C | 19.6°C | 11.7°C | 35.5°C | 2.9°C | 22 mm | 45% | 2.1 m/s | 6.3 |
| 2017 | 27.0°C | 19.8°C | 12.5°C | 32.3°C | 10.0°C | 16 mm | 50% | 1.7 m/s | 6.3 |
| 2016 | 28.6°C | 20.3°C | 12.0°C | 33.5°C | 5.7°C | 7 mm | 34% | 2.3 m/s | 6.8 |
| 2015 | 27.7°C | 20.0°C | 12.2°C | 33.7°C | 6.3°C | 37 mm | 46% | 2.2 m/s | 6.1 |
| 2014 🌧️ | 24.5°C | 18.2°C | 11.9°C | 32.3°C | 5.3°C | 106 mm | 59% | 1.7 m/s | 5.4 |
| 2013 | 30.4°C | 22.5°C | 14.6°C | 34.4°C | 12.0°C | 16 mm | 36% | 2.3 m/s | 6.3 |
| 2012 | 30.6°C | 22.0°C | 13.5°C | 35.0°C | 7.7°C | 9 mm | 35% | 2 m/s | 6.7 |
| 2011 | 29.2°C | 20.9°C | 12.5°C | 33.8°C | 8.3°C | 30 mm | 45% | 2 m/s | 6.8 |
| 2010 | 27.4°C | 19.1°C | 10.9°C | 33.1°C | 4.7°C | 34 mm | 43% | 2.6 m/s | 6.6 |
| 2009 | 26.8°C | 19.0°C | 11.3°C | 33.2°C | 5.6°C | 26 mm | 48% | 1.9 m/s | 6.3 |
| 2008 | 28.6°C | 20.2°C | 11.8°C | 33.4°C | 5.9°C | 26 mm | 37% | 2.3 m/s | 6.9 |
| 2007 | 29.4°C | 21.4°C | 13.5°C | 34.3°C | 8.6°C | 29 mm | 38% | 2.5 m/s | 6.3 |
| 2006 | 28.0°C | 19.6°C | 11.2°C | 32.5°C | 3.7°C | 16 mm | 38% | 2.3 m/s | 6.8 |
| 2005 | 27.8°C | 19.9°C | 12.0°C | 33.9°C | 4.5°C | 28 mm | 42% | 2.1 m/s | 6.6 |
| 2004 | 26.8°C | 19.1°C | 11.4°C | 33.6°C | 5.2°C | 45 mm | 43% | 2.3 m/s | 6.4 |
| 2003 | 31.0°C | 22.9°C | 14.8°C | 37.2°C | 9.1°C | 26 mm | 38% | 2.4 m/s | 6.1 |
| 2002 | 27.8°C | 19.6°C | 11.4°C | 32.0°C | 6.9°C | 7 mm | 31% | 2.5 m/s | 6.8 |
| 2001 🔥 | 31.5°C | 23.0°C | 14.5°C | 35.3°C | 10.5°C | 7 mm | 31% | 2.1 m/s | 6.6 |
| 2000 | 30.4°C | 22.0°C | 13.7°C | 37.3°C | 9.2°C | 23 mm | 33% | 2.7 m/s | 6.4 |
| 1999 | 28.4°C | 20.5°C | 12.7°C | 32.7°C | 6.3°C | 42 mm | 44% | 2.3 m/s | 6.2 |
| 1998 | 29.2°C | 21.2°C | 13.1°C | 33.6°C | 9.3°C | 16 mm | 43% | 2 m/s | 6.5 |
| 1997 | 27.3°C | 19.8°C | 12.3°C | 32.5°C | 7.8°C | 43 mm | 51% | 2.3 m/s | 6.7 |
| 1996 | 28.4°C | 19.9°C | 11.4°C | 33.3°C | 6.6°C | 9 mm | 36% | 2.3 m/s | 6.9 |
| 1995 | 27.8°C | 19.7°C | 11.6°C | 33.0°C | 5.8°C | 25 mm | 41% | 2.6 m/s | 6.8 |
| 1994 | 30.5°C | 22.3°C | 14.1°C | 36.1°C | 7.4°C | 18 mm | 33% | 2.3 m/s | 6.6 |
| 1993 ❄️ | 24.4°C | 16.8°C | 9.2°C | 30.6°C | 1.6°C | 51 mm | 51% | 2.3 m/s | 6.5 |
| 1992 | 28.0°C | 20.1°C | 12.2°C | 35.0°C | 1.2°C | 10 mm | 32% | 2.3 m/s | 6.6 |
| 1991 | 28.9°C | 21.1°C | 13.2°C | 33.3°C | 9.2°C | 30 mm | 41% | 2.2 m/s | 6.4 |
| 1990 | 28.6°C | 20.4°C | 12.2°C | 36.0°C | 8.1°C | 22 mm | 38% | 2.3 m/s | 6.2 |
| 1989 | 26.0°C | 18.5°C | 10.9°C | 32.6°C | 3.2°C | 27 mm | 42% | 2.4 m/s | 6 |
| 1988 | 29.5°C | 20.5°C | 11.5°C | 34.4°C | 6.6°C | 8 mm | 25% | 2.6 m/s | 7 |
| 1987 | 26.4°C | 18.1°C | 9.8°C | 31.2°C | 5.0°C | 15 mm | 39% | 2.3 m/s | 6.5 |
| 1986 | 28.9°C | 20.7°C | 12.6°C | 33.8°C | 8.6°C | 29 mm | 41% | 2.1 m/s | 6.3 |
| 1985 | 26.6°C | 18.2°C | 9.8°C | 33.6°C | 4.8°C | 4 mm | 34% | 2.7 m/s | 6.6 |
| 1984 | 27.2°C | 19.6°C | 12.0°C | 32.1°C | 8.2°C | 40 mm | 50% | 2 m/s | 5.8 |
| 1983 | 27.6°C | 20.7°C | 13.7°C | 34.4°C | 9.4°C | 56 mm | 54% | 1.9 m/s | — |
| 1982 | 28.8°C | 20.9°C | 13.0°C | 33.4°C | 8.7°C | 30 mm | 44% | 2.4 m/s | — |
| 1981 | 30.4°C | 21.6°C | 12.9°C | 34.4°C | 6.0°C | 10 mm | 33% | 2.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 28.3°C with lows near 12.5°C (mean 20.4°C), based on 45 years of NASA POWER data.
August averages 28 mm of rainfall in Idaho Falls, one of the drier months. The wettest on record was 106 mm in 2014.
The hottest August reached 37.3°C in 2000. The coldest dipped to 1.2°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.8°C. Daytime highs moved from 28.1°C to 28.3°C and overnight lows from 12.3°C to 13.6°C over the same span.
August is one of the warmer months of the year in Idaho Falls and one of the drier months, so plan for around 28.3°C daytime highs and 12.5°C at night.
Not quite — August is the 11th coolest month in Idaho Falls, averaging 20.4°C.
For August in Idaho Falls, pack light layers you can adjust through the day, with typical highs of 28.3°C and lows of 12.5°C.
Relative humidity in August averages 41% — relatively dry.
Average wind speed in August is 2.2 m/s. The windiest August on record averaged 2.7 m/s (1985).
The wettest August on record was 2014 with 106 mm. On average, August sees 28 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 Idaho Falls behaves each August, 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 August specifically, along with year-by-year records and how the month has changed over the decades.
