Hillsboro in Winter
In winter (December, January and February), Hillsboro sees average daytime highs around 47°F and overnight lows near 36°F, with 19.9 in of precipitation over about 49 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Over the season highs climb from about 46°F in early December to 51°F by late February. The sky is clear or mostly clear about 14% of the time across winter, and the air most often feels dry.
Winter is Hillsboro's weakest 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
- 47°F
- coldest season of the year
- Avg overnight low
- 36°F
- Precipitation
- 19.9 in
- 49 wet days
- Avg wind
- 5 mph
- Travel score
- 1.2
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Hillsboro in Winter
Over the season highs climb from about 46°F in early December to 51°F by late February.
A typical winter day in Hillsboro reaches about 47°F and drops to 36°F overnight. The warmest of the three months is February, the coolest December.
How winter really feels in Hillsboro
Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 43 that feel at or below 32°F.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Hillsboro weather by month
How the three winter months (December, January and February) 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 Winter
The sky is clear or mostly clear about 14% of the time across winter.
Chance of precipitation in Winter
Hillsboro gets around 19.9 in of rain and snow over 49 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 5 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 8 h 48 min in early December to 10 h 42 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 1.4 kWh/m².
Hazard calendar for Hillsboro
In winter, Hillsboro overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Hillsboro's rainy season runs October–April, when most of the year's rain falls.
Is winter a good time to visit Hillsboro?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Hillsboro.
What to pack for Hillsboro in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Hillsboro sees daytime highs around 47°F and nights near 36°F. Pack a warm layer and rain gear. Worth having: a heavy coat. About 49 days see rain.
Sea temperature near Hillsboro in Winter
The nearest coast averages about 50°F across winter — 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 Winter
Clear-sky midday UV across winter averages around 1. 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 Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter 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.