Lewiston weather in August: Lewiston, Idaho: normal highs, lows, rain and records for August
Lewiston in August has a normal high of 90°F and a normal low of 60°F, a daily mean of 75°F, falling from 94°F on the 1st to 86°F by the 31st. Measurable precipitation falls on 3 days in a normal August, 0.51 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 32°C and low of 16°C, 13 mm of precipitation in August.
- NOAA stationLewiston Airport
- Station IDUSW00024149
- Location46.37°N 117.02°W
- Elevation1,436 ft (438 m)
- Population34,693
- Jan 42° 30°
- Feb 47° 32°
- Mar 55° 36°
- Apr 62° 41°
- May 72° 48°
- Jun 79° 54°
- Jul 91° 61°
- Aug 90° 60°
- Sep 80° 52°
- Oct 63° 42°
- Nov 49° 35°
- Dec 41° 30°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Lewiston in August?
The normal high is 90°F and the normal low 60°F, for a daily mean of 75.2°F. August is 0.6°F cooler than July and 9.3°F warmer than September. August is the 2nd warmest month of the year in Lewiston and the 11th wettest. Across the month the normal high falls 8°F, from 94°F on August 1 to 86°F on August 31. From one year to the next August's mean temperature typically moves about 1.9°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 73°F and 77°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 13%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 94°F | 63°F | 11% | 3% |
| August 8 | 93°F | 62°F | 11% | 4% |
| August 15 | 91°F | 61°F | 11% | 4% |
| August 22 | 89°F | 59°F | 11% | 4% |
| August 31 | 86°F | 57°F | 13% | 5% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 94°F | 63°F | 11% | 3% | 14 h 50 min |
| August 2 | 94°F | 63°F | 11% | 3% | 14 h 50 min |
| August 3 | 93°F | 63°F | 11% | 3% | 14 h 50 min |
| August 4 | 93°F | 63°F | 11% | 3% | 14 h 40 min |
| August 5 | 93°F | 63°F | 11% | 4% | 14 h 40 min |
| August 6 | 93°F | 62°F | 11% | 4% | 14 h 40 min |
| August 7 | 93°F | 62°F | 11% | 4% | 14 h 40 min |
| August 8 | 93°F | 62°F | 11% | 4% | 14 h 30 min |
| August 9 | 92°F | 62°F | 11% | 4% | 14 h 30 min |
| August 10 | 92°F | 62°F | 11% | 4% | 14 h 30 min |
| August 11 | 92°F | 62°F | 11% | 4% | 14 h 30 min |
| August 12 | 92°F | 61°F | 11% | 4% | 14 h 20 min |
| August 13 | 91°F | 61°F | 11% | 4% | 14 h 20 min |
| August 14 | 91°F | 61°F | 11% | 4% | 14 h 20 min |
| August 15 | 91°F | 61°F | 11% | 4% | 14 h 10 min |
| August 16 | 90°F | 61°F | 11% | 4% | 14 h 10 min |
| August 17 | 90°F | 60°F | 11% | 4% | 14 h 10 min |
| August 18 | 90°F | 60°F | 11% | 4% | 14 h 10 min |
| August 19 | 89°F | 60°F | 11% | 4% | 14 h |
| August 20 | 89°F | 60°F | 11% | 4% | 14 h |
| August 21 | 89°F | 59°F | 11% | 4% | 14 h |
| August 22 | 89°F | 59°F | 11% | 4% | 13 h 50 min |
| August 23 | 88°F | 59°F | 12% | 4% | 13 h 50 min |
| August 24 | 88°F | 59°F | 12% | 5% | 13 h 50 min |
| August 25 | 88°F | 58°F | 12% | 5% | 13 h 40 min |
| August 26 | 87°F | 58°F | 12% | 5% | 13 h 40 min |
| August 27 | 87°F | 58°F | 12% | 5% | 13 h 40 min |
| August 28 | 87°F | 58°F | 12% | 5% | 13 h 40 min |
| August 29 | 86°F | 57°F | 12% | 5% | 13 h 30 min |
| August 30 | 86°F | 57°F | 12% | 5% | 13 h 30 min |
| August 31 | 86°F | 57°F | 13% | 5% | 13 h 30 min |
- Normal high
- 90°FAugust average
- Normal low
- 60°FAugust average
- Precipitation
- 0.51 inmonth total
- Days with precipitation
- 30.01 inch or more
- Days at 90°F or more
- 17
- Daylight
- 14 h 50 min to 13 h 30 minAugust 1 to August 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 27
- Sunshine
- 88%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024149; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lewiston in August?
On a given August day the chance of 0.01 inch or more is 11% on average, highest around August 31 (13%). In all, 0.51 in falls on 3 days of a normal August.
In a normal August in Lewiston, 17 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024149.
How humid and windy is Lewiston in August?
At 3 p.m. the normal temperature is 83°F with 23% relative humidity and a dew point of 42°F; at 6 a.m. it is 59°F with 58% humidity. The wind averages 5.0 mph, most often from the northwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 59°F | 44°F | 58% | 3.1 mph | 85% |
| 9 a.m. | 68°F | 46°F | 45% | 4.1 mph | 84% |
| noon | 78°F | 44°F | 30% | 5.7 mph | 85% |
| 3 p.m. | 83°F | 42°F | 23% | 7.7 mph | 86% |
| 6 p.m. | 79°F | 42°F | 26% | 6.9 mph | 87% |
| 9 p.m. | 70°F | 41°F | 35% | 5.9 mph | 89% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024149. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in Lewiston?
The warmest August temperature on Lewiston's official record (since 1881) is 115°F, on August 4, 1961; the coldest is 41°F, on August 20, 1945. The wettest August brought 2.96 in (1989).
The August mean against the 1991-2020 normal of 75.2°F: 2021 76.0°F (+0.8), 2022 80.1°F (+4.9), 2023 77.2°F (+2.0), 2024 76.3°F (+1.1), 2025 77.8°F (+2.6), 2026 75.9°F (+0.7). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 76.0°F | +0.8°F | 0.23 in |
| 2022 | 80.1°F | +4.9°F | 0.16 in |
| 2023 | 77.2°F | +2.0°F | 0.83 in |
| 2024 | 76.3°F | +1.1°F | 0.44 in |
| 2025 | 77.8°F | +2.6°F | 0.29 in |
| 2026 | 75.9°F | +0.7°F | 0.09 in |
Source: records: ACIS, NWS threaded record LWSthr; recent months: ACIS, station USW00024149. Records and recent months use complete months only.
How does August in Lewiston compare across Idaho?
Across the 85 places PlainClimate covers in Idaho, August normal highs run from 69°F in Mullan to 97°F in Glenns Ferry; Lewiston's is 90°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.