Hillsboro weather in August: Hillsboro, Oregon: normal highs, lows, rain and records for August
Hillsboro in August has a normal high of 82°F and a normal low of 52°F, a daily mean of 67°F, falling from 84°F on the 1st to 80°F by the 31st. Measurable precipitation falls on 4 days in a normal August, 0.48 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 28°C and low of 11°C, 12 mm of precipitation in August.
- NOAA stationPortland-Hillsboro Airport
- Station IDUSW00094261
- Location45.54°N 122.95°W
- Elevation204 ft (62 m)
- Population110,337
- Jan 47° 34°
- Feb 51° 34°
- Mar 56° 37°
- Apr 61° 39°
- May 69° 45°
- Jun 74° 49°
- Jul 82° 52°
- Aug 82° 52°
- Sep 76° 48°
- Oct 64° 41°
- Nov 53° 37°
- Dec 46° 33°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Hillsboro in August?
The normal high is 82°F and the normal low 52°F, for a daily mean of 67.1°F. August is 0.1°F cooler than July and 5.1°F warmer than September. August is the 2nd warmest month of the year in Hillsboro and the 11th wettest. Across the month the normal high falls 4°F, from 84°F on August 1 to 80°F on August 31. From one year to the next August's mean temperature typically moves about 1.8°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 65°F and 69°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 19%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 84°F | 53°F | 8% | 3% |
| August 8 | 84°F | 53°F | 9% | 4% |
| August 15 | 83°F | 52°F | 11% | 4% |
| August 22 | 82°F | 51°F | 14% | 5% |
| August 31 | 80°F | 50°F | 19% | 7% |
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 | 84°F | 53°F | 8% | 3% | 14 h 50 min |
| August 2 | 84°F | 53°F | 8% | 3% | 14 h 50 min |
| August 3 | 84°F | 53°F | 8% | 3% | 14 h 40 min |
| August 4 | 84°F | 53°F | 9% | 3% | 14 h 40 min |
| August 5 | 84°F | 53°F | 9% | 3% | 14 h 40 min |
| August 6 | 84°F | 53°F | 9% | 3% | 14 h 30 min |
| August 7 | 84°F | 53°F | 9% | 3% | 14 h 30 min |
| August 8 | 84°F | 53°F | 9% | 4% | 14 h 30 min |
| August 9 | 83°F | 53°F | 10% | 4% | 14 h 30 min |
| August 10 | 83°F | 53°F | 10% | 4% | 14 h 20 min |
| August 11 | 83°F | 52°F | 10% | 4% | 14 h 20 min |
| August 12 | 83°F | 52°F | 10% | 4% | 14 h 20 min |
| August 13 | 83°F | 52°F | 11% | 4% | 14 h 20 min |
| August 14 | 83°F | 52°F | 11% | 4% | 14 h 10 min |
| August 15 | 83°F | 52°F | 11% | 4% | 14 h 10 min |
| August 16 | 83°F | 52°F | 12% | 4% | 14 h 10 min |
| August 17 | 82°F | 52°F | 12% | 4% | 14 h |
| August 18 | 82°F | 52°F | 12% | 5% | 14 h |
| August 19 | 82°F | 52°F | 13% | 5% | 14 h |
| August 20 | 82°F | 52°F | 13% | 5% | 14 h |
| August 21 | 82°F | 51°F | 14% | 5% | 13 h 50 min |
| August 22 | 82°F | 51°F | 14% | 5% | 13 h 50 min |
| August 23 | 82°F | 51°F | 15% | 5% | 13 h 50 min |
| August 24 | 81°F | 51°F | 15% | 6% | 13 h 40 min |
| August 25 | 81°F | 51°F | 16% | 6% | 13 h 40 min |
| August 26 | 81°F | 51°F | 16% | 6% | 13 h 40 min |
| August 27 | 81°F | 51°F | 17% | 6% | 13 h 40 min |
| August 28 | 81°F | 51°F | 17% | 6% | 13 h 30 min |
| August 29 | 81°F | 50°F | 18% | 6% | 13 h 30 min |
| August 30 | 81°F | 50°F | 18% | 7% | 13 h 30 min |
| August 31 | 80°F | 50°F | 19% | 7% | 13 h 20 min |
- Normal high
- 82°FAugust average
- Normal low
- 52°FAugust average
- Precipitation
- 0.48 inmonth total
- Days with precipitation
- 40.01 inch or more
- Days at 90°F or more
- 6
- Daylight
- 14 h 50 min to 13 h 20 minAugust 1 to August 31
- Days at 70°F or more
- 29
- Days at 80°F or more
- 19
- Sunshine
- 83%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00094261; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Hillsboro in August?
On a given August day the chance of 0.01 inch or more is 12% on average, highest around August 31 (19%). In all, 0.48 in falls on 4 days of a normal August.
In a normal August in Hillsboro, 6 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00094261.
How humid and windy is Hillsboro in August?
At 3 p.m. the normal temperature is 78°F with 39% relative humidity and a dew point of 51°F; at 6 a.m. it is 52°F with 89% humidity. The wind averages 4.5 mph, most often from the north-northwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 52°F | 49°F | 89% | 1.3 mph | 67% |
| 9 a.m. | 64°F | 53°F | 66% | 2.6 mph | 64% |
| noon | 73°F | 52°F | 47% | 4.9 mph | 64% |
| 3 p.m. | 78°F | 51°F | 39% | 6.6 mph | 67% |
| 6 p.m. | 75°F | 52°F | 45% | 8.3 mph | 74% |
| 9 p.m. | 64°F | 52°F | 65% | 6.8 mph | 81% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00094261. 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 Hillsboro?
The warmest August temperature on Hillsboro's official record (since 1929) is 107°F, on August 14, 2023; the coldest is 30°F, on August 30, 1930. The wettest August brought 3.84 in (1968).
The August mean against the 1991-2020 normal of 67.1°F: 2021 69.0°F (+2.0), 2022 71.2°F (+4.1), 2023 71.6°F (+4.5), 2024 68.2°F (+1.1), 2025 71.3°F (+4.2), 2026 68.7°F (+1.6). 6 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 69.0°F | +2.0°F | 0.02 in |
| 2022 | 71.2°F | +4.1°F | 0.00 in |
| 2023 | 71.6°F | +4.5°F | 0.75 in |
| 2024 | 68.2°F | +1.1°F | 1.02 in |
| 2025 | 71.3°F | +4.2°F | 0.42 in |
| 2026 | 68.7°F | +1.6°F | 0.00 in |
Source: records: ACIS, NWS threaded record HIOthr; recent months: ACIS, station USW00094261. Records and recent months use complete months only.
How does August in Hillsboro compare across Oregon?
Across the 105 places PlainClimate covers in Oregon, August normal highs run from 64°F in Newport to 94°F in Cave Junction; Hillsboro's is 82°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.