Hillsboro in Summer
In summer (June, July and August), Hillsboro sees average daytime highs around 77°F and overnight lows near 55°F, with 2.5 in of rain over about 12 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 69°F in early June to 78°F by late August. The sky is clear or mostly clear about 50% of the time across summer, and the air most often feels dry.
Summer is Hillsboro's best season of the year to visit on our travel score. For the whole year in context, see Hillsboro's year-round climate.
- Avg daytime high
- 77°F
- warmest season of the year
- Avg overnight low
- 55°F
- Rainfall
- 2.5 in
- 12 wet days
- Avg wind
- 5 mph
- Travel score
- 7.8
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Hillsboro in Summer
Over the season highs climb from about 69°F in early June to 78°F by late August.
A typical summer day in Hillsboro reaches about 77°F and drops to 55°F overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Hillsboro
Once humidity and wind are folded in, summer brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Hillsboro weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 46° / 36° | 6.8 | 17.1 | 1.9 | 8.9 | 1.0 |
| Feb | 49° / 37° | 5.2 | 14.2 | 1.6 | 10.1 | 1.8 |
| Mar | 54° / 39° | 5.9 | 17.3 | 0.9 | 11.6 | 2.7 |
| Apr | 59° / 42° | 4.5 | 15.6 | 0.1 | 13.2 | 3.8 |
| May | 66° / 47° | 2.7 | 10.6 | 0 | 14.7 | 5.9 |
| Jun | 72° / 52° | 1.6 | 7.2 | 0 | 15.4 | 7.1 |
| Jul | 80° / 56° | 0.4 | 2.2 | 0 | 15.1 | 8.2 |
| Aug | 80° / 57° | 0.5 | 2.5 | 0 | 13.9 | 8.1 |
| Sep | 74° / 53° | 1.7 | 6 | 0 | 12.3 | 7.7 |
| Oct | 62° / 46° | 4.2 | 11.5 | 0 | 10.7 | 5.1 |
| Nov | 51° / 40° | 7.0 | 17.3 | 0.5 | 9.3 | 2.0 |
| Dec | 45° / 36° | 8.0 | 17.5 | 2.3 | 8.6 | 0.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 50% of the time across summer.
Chance of precipitation in Summer
Hillsboro gets around 2.5 in of rain over 12 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 5 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 h 12 min in early June to 13 h 12 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.3 kWh/m².
Hazard calendar for Hillsboro
None of Hillsboro's seasonal hazards peak in summer. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
Hillsboro's rainy season runs October–April, when most of the year's rain falls.
Is summer a good time to visit Hillsboro?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is one of the better times to visit Hillsboro for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Hillsboro in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Hillsboro sees daytime highs around 77°F and nights near 55°F. Pack sun protection. Worth having: light clothes. About 12 days see rain.
Sea temperature near Hillsboro in Summer
The nearest coast averages about 58°F across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 44 mi away) is warmest in August at about 59°F and coldest in February near 49°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 50 | 49 | 50 | 51 | 54 | 57 | 58 | 59 | 58 | 55 | 53 | 50 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 50 | Bracing |
| Feb | 49 | Bracing |
| Mar | 50 | Bracing |
| Apr | 51 | Bracing |
| May | 54 | Bracing |
| Jun | 57 | Bracing |
| Jul | 58 | Bracing |
| Aug | 59 | Bracing |
| Sep | 58 | Bracing |
| Oct | 55 | Bracing |
| Nov | 53 | Bracing |
| Dec | 50 | Bracing |
UV index in Hillsboro in Summer
Clear-sky midday UV across summer averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Hillsboro peaks around July 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 8 | 7 | 8 | 7 | 4 | 3 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | Very high | High | Very high | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | Moderate |
| May | 8 | Very high |
| Jun | 7 | High |
| Jul | 8 | Very high |
| Aug | 7 | High |
| Sep | 4 | Moderate |
| Oct | 3 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Air quality in Hillsboro in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Hillsboro is worst in September — around 22 µg/m³ PM2.5 (moderate), about 3.0× the cleanest month (January, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 7 | 9 | 11 | 11 | 10 | 9 | 8 | 13 | 22 | 14 | 9 | 7 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 7 | Good |
| Feb | 9 | Good |
| Mar | 11 | Good |
| Apr | 11 | Good |
| May | 10 | Good |
| Jun | 9 | Good |
| Jul | 8 | Good |
| Aug | 13 | Moderate |
| Sep | 22 | Moderate |
| Oct | 14 | Moderate |
| Nov | 9 | Good |
| Dec | 7 | Good |
Where is Hillsboro?
Hillsboro sits at 45.5°N, 123.0°W, 194 ft above sea level, in United States. The nearest listed city is Forest Grove, 5.6 mi away.
Topography around Hillsboro
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Hillsboro.
Within 2 miles, the terrain around Hillsboro has only modest variations in elevation — a maximum elevation change of 141 ft around an average of 174 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,532 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,806 ft.
The land around Hillsboro is covered by trees (44%) and artificial surfaces (25%) within 2 miles, trees (49%), grassland (21%) and cropland (21%) within 10 miles, and trees (76%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hillsboro (45.5229°, -122.9898°, elevation 194 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.