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Riley, OR Climate

Temperature, precipitation, and comfort score from NOAA NCEI 1991-2020 normals →

30-year climate normals from 1 weather station (1991-2020).

Riley, Oregon has an average annual temperature of 45°F and a climate comfort score of 47/100 (Moderate). Annual precipitation totals 10.4". Based on NOAA 30-year normals (1991–2020).

Avg Temperature

45°F (7°C)

Avg High

59°F

Avg Low

31°F

Annual Precip

10.4"

Comfort Score

47/100

Moderate

Climate Comfort Score

47/100

Moderate

Avg Annual Temperature

45°F

30-year mean (NOAA NCEI)

Annual Precipitation

10.4"

Liquid-equivalent total

Comfort score vs national 100-point ceiling (Riley) 47.0%
National median (≈55)

PlainClimate composite — temperature mildness, humidity, precipitation, extreme-weather frequency. Moderate for the Riley area.

Warming context for Riley

Methodology

How the U.S. land temperature anomaly tracks against the global mean since 1900. The current NOAA 1991-2020 normal for Riley captures average conditions across the spread shown — the most recent decade is warmer than the 30-year mean.

Warming context — U.S. vs global, with Paris reference lines Anomaly chart from 1900 to 2024. Local series shows warming of 0.11 °C per decade versus a global rate of 0.11 °C per decade (ratio 1.00). Paris Agreement thresholds at 1.5 and 2.0 °C are dashed. -1.0°C -0.5°C +0.0°C +0.5°C +1.0°C +1.5°C +2.0°C +2.5°C Paris 1.5°C Paris 2.0°C 1900192019401960198020002020
  • United States land mean (NOAA NCEI) +0.11 °C/decade
  • Global anomaly (NASA GISTEMP) +0.11 °C/decade
  • Paris Agreement thresholds 1.5°C / 2.0°C
Sources: NOAA NCEI, NASA GISTEMP. Paris thresholds per IPCC AR6 WG1.

Monthly Temperatures

Average daily high and low temperatures by month

Month Avg High Avg Low Mean
January 37°F (3°C) 17°F (-8°C) 27°F (-3°C)
February 40°F (5°C) 20°F (-7°C) 30°F (-1°C)
March 49°F (10°C) 25°F (-4°C) 37°F (3°C)
April 55°F (13°C) 27°F (-3°C) 41°F (5°C)
May 65°F (18°C) 35°F (2°C) 50°F (10°C)
June 74°F (23°C) 42°F (6°C) 58°F (14°C)
July 86°F (30°C) 51°F (10°C) 69°F (20°C)
August 84°F (29°C) 48°F (9°C) 66°F (19°C)
September 75°F (24°C) 40°F (4°C) 57°F (14°C)
October 61°F (16°C) 30°F (-1°C) 45°F (7°C)
November 44°F (7°C) 21°F (-6°C) 33°F (0°C)
December 35°F (2°C) 16°F (-9°C) 25°F (-4°C)

Monthly Precipitation

Average monthly rainfall

January 1.0"

10.4 days with precipitation

February 1.0"

10.6 days with precipitation

March 1.0"

11.7 days with precipitation

April 1.0"

10.8 days with precipitation

May 1.3"

9.7 days with precipitation

June 0.9"

6.1 days with precipitation

July 0.4"

2.5 days with precipitation

August 0.2"

2.4 days with precipitation

September 0.4"

2.9 days with precipitation

October 0.8"

7.0 days with precipitation

November 1.0"

10.1 days with precipitation

December 1.4"

13.5 days with precipitation

Frost Dates & Growing Season

First Fall Freeze

September 11

50% probability date

Last Spring Freeze

June 11

50% probability date

Heating & Cooling Degree Days

Annual totals indicate energy demand for heating and cooling

Heating Degree Days

7,605

Higher = more heating needed

Cooling Degree Days

291

Higher = more cooling needed

Warmest Month

July

Coldest Month

December

Related Data

Climate Guides

Climate Insight: Riley, OR

The NOAA 1991–2020 climate normals describe Riley, Oregon as a location with an annual average temperature of 45°F, ranging from a mean daily high of 59°F to a mean daily low of 31°F. July is typically the warmest month of the year, while December is the coldest. These thirty-year averages, computed from station USW00004128, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.

Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. Riley receives roughly 10.4 inches of precipitation each year, predominantly as rainfall. Growing-season length varies with elevation and microclimate, with the last spring freeze near June 11 and the first fall freeze near September 11. For energy use, 7,605 heating degree days and 291 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Riley scores 47/100 (Moderate), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows — shoulder seasons for mild highs and lows, peak summer for July-driven heat, or deep winter for December-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.

Frequently Asked Questions

What is the average temperature in Riley, OR?
The average annual temperature in Riley, Oregon is 45°F. The warmest month averages 86°F (30°C) and the coldest averages 16°F (-9°C).
How much rain does Riley get?
Riley receives 10.4 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Riley?
Riley has a climate comfort score of 47/100 (Moderate). This score considers temperature mildness, humidity, precipitation, and extreme weather frequency.
When is the growing season in Riley?
Growing season data is not available for Riley.
How much energy does heating and cooling require in Riley?
Riley has 7,605 heating degree days and 291 cooling degree days annually. Higher heating degree days indicate greater winter energy demand, while higher cooling degree days indicate greater summer cooling needs.
Where does this Riley climate data come from?
All climate data comes from NOAA U.S. Climate Normals v1.0.1, covering the 30-year period from 1991 to 2020. Data is collected from weather station USW00004128. These 30-year averages are the standard reference for typical weather conditions.

Data Sources

Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USW00004128. For informational purposes only.

Related

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial