Hillsboro receives its highest rainfall in Dec, while humidity peaks during winter months.
🌧️ Wettest:Dec — 253 mm☀️ Driest:Jul — 17 mm
💧 Humidity peaks at 94% in Dec · annual avg 85%
🌍 Climate Summary
Avg Annual Temp:53.1°F
Avg Annual Rainfall:1548 mm
Avg Humidity:85%
Data Period:1981 – 2025
Hillsboro Climate Overview
Hillsboro has a temperate climate with warm summers and cold winters.
Temperatures peak in Aug and drop to their lowest in Dec,
while rainfall is highest during winter months.
Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions.
📈 Yearly Trends
The warmest year in Hillsboro's recorded history was 2015
(avg: 55.6°F),
while the coldest year was 1985
(avg: 49.1°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ Hillsboro's temperature has remained relatively stable over the past decade
📈 Minimum temperatures show a slight warming trend in recent years
🌧️ Rainfall has increased noticeably in recent years compared to earlier periods
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
Hillsboro's temperatures has remained relatively stable over the past decade.
The highest recorded temperature reached
108.9°F in Jun 2021,
while the lowest dropped to
-0.2°F in Feb 1989.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in Hillsboro shows noticeable variation. Rainfall has increased noticeably in recent years compared to earlier periods.
Based on 45 years of data (1981–2025), Aug is typically the hottest month in Hillsboro, Oregon, with average high temperatures around 93.4°F.
What is the coldest month in Hillsboro?▼
Dec is the coldest month in Hillsboro, with average low temperatures around 21.9°F.
What is the rainiest month in Hillsboro?▼
Dec receives the most rainfall with approximately 253 mm, while Jul is the driest with 17 mm.
What was the highest temperature ever recorded in Hillsboro?▼
The highest recorded temperature was 108.9°F in Jun 2021. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Hillsboro?▼
The lowest recorded temperature was -0.2°F in Feb 1989.
How many years of data does this page cover?▼
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Hillsboro get?▼
Hillsboro receives the most sunlight in Jul with an average solar radiation of 6.67 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Oregon.
Where does this weather data come from?▼
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
📚 Data Source
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.