Climate Comfort Score
67/100
Good
2026 data Public-data reference. official source
30-year climate normals from 1 weather station (1991-2020).
Olney, Illinois has an average annual temperature of 54°F and a climate comfort score of 67/100 (Good). Annual precipitation totals 48.8", including 10.5" of snow. Based on NOAA 30-year normals (1991–2020).
Avg Temperature
54°F (12°C)
Avg High
65°F
Avg Low
44°F
Annual Precip
48.8"
Annual Snow
10.5"
Comfort Score
67/100
Good
Avg Annual Temperature
54°F
30-year mean (NOAA NCEI)
Annual Precipitation
48.8"
Plus 10.5" of snow
Comfort score vs national 100-point ceiling (Olney) 67.0%
National median (≈55)
PlainClimate composite — temperature mildness, humidity, precipitation, extreme-weather frequency. Good for the Olney area.
Warming context for Olney
MethodologyHow the U.S. land temperature anomaly tracks against the global mean since 1900. The current NOAA 1991-2020 normal for Olney captures average conditions across the spread shown — the most recent decade is warmer than the 30-year mean.
- 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
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 38°F (3°C) | 21°F (-6°C) | 29°F (-1°C) | 3.5" | 3.6" | 25.6 | 0.0 |
| February | 43°F (6°C) | 24°F (-5°C) | 33°F (1°C) | 2.6" | 2.6" | 20.7 | 0.0 |
| March | 53°F (12°C) | 32°F (0°C) | 43°F (6°C) | 4.2" | 1.1" | 15.3 | 0.0 |
| April | 66°F (19°C) | 43°F (6°C) | 54°F (12°C) | 5.0" | 0.0" | 3.8 | 0.0 |
| May | 75°F (24°C) | 53°F (12°C) | 64°F (18°C) | 5.6" | 0.0" | 0.1 | 0.8 |
| June | 84°F (29°C) | 62°F (17°C) | 73°F (23°C) | 4.8" | 0.0" | 0.0 | 7.0 |
| July | 87°F (30°C) | 66°F (19°C) | 76°F (25°C) | 5.0" | 0.0" | 0.0 | 11.0 |
| August | 86°F (30°C) | 64°F (18°C) | 75°F (24°C) | 3.2" | 0.0" | 0.0 | 8.5 |
| September | 80°F (27°C) | 56°F (13°C) | 68°F (20°C) | 3.3" | 0.0" | 0.0 | 4.2 |
| October | 69°F (20°C) | 44°F (7°C) | 56°F (14°C) | 3.8" | 0.0" | 3.4 | 0.2 |
| November | 54°F (12°C) | 34°F (1°C) | 44°F (7°C) | 4.3" | 0.5" | 13.6 | 0.0 |
| December | 42°F (6°C) | 26°F (-4°C) | 34°F (1°C) | 3.5" | 2.7" | 22.3 | 0.0 |
Monthly Precipitation
Average monthly rainfall and snowfall
January 3.5"
Snow: 3.6"
10.6 days with precipitation
February 2.6"
Snow: 2.6"
8.7 days with precipitation
March 4.2"
Snow: 1.1"
11.8 days with precipitation
April 5.0"
11.2 days with precipitation
May 5.6"
12.7 days with precipitation
June 4.8"
10.5 days with precipitation
July 5.0"
9.2 days with precipitation
August 3.2"
8.1 days with precipitation
September 3.3"
7.7 days with precipitation
October 3.8"
9.1 days with precipitation
November 4.3"
Snow: 0.5"
9.6 days with precipitation
December 3.5"
Snow: 2.7"
10.9 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
October 23
50% probability date
Last Spring Freeze
April 15
50% probability date
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,102
Higher = more heating needed
Cooling Degree Days
1,195
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Related Data
PlainEnviro
EPA environmental data — pollution, water quality, and environmental health by location
PlainCarbon
Carbon emissions data — greenhouse gas reporting and facility-level CO2 data
PlainHazard
Natural disaster data — weather-related hazards, FEMA declarations, and risk profiles
PlainAirData
EPA air quality data — AQI readings, pollutant levels, and air quality trends
Climate Guides
Climate Insight: Olney, IL
The NOAA 1991–2020 climate normals describe Olney, Illinois as a location with an annual average temperature of 54°F, ranging from a mean daily high of 65°F to a mean daily low of 44°F. July is typically the warmest month of the year, while January is the coldest. These thirty-year averages, computed from station USC00116446, 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. Olney receives roughly 48.8 inches of precipitation each year, with 10.5 inches typically falling as snow. Growing-season length varies with elevation and microclimate, with the last spring freeze near April 15 and the first fall freeze near October 23. For energy use, 5,102 heating degree days and 1,195 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Olney scores 67/100 (Good), 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 January-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 Olney, IL? ▼
The average annual temperature in Olney, Illinois is 54°F. The warmest month averages 87°F (30°C) and the coldest averages 21°F (-6°C).
How much rain does Olney get? ▼
Olney receives 48.8 inches of precipitation annually, including 10.5 inches of snow. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Olney? ▼
Olney has a climate comfort score of 67/100 (Good). This score considers temperature mildness, humidity, precipitation, and extreme weather frequency.
When is the growing season in Olney? ▼
Growing season data is not available for Olney.
How much energy does heating and cooling require in Olney? ▼
Olney has 5,102 heating degree days and 1,195 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 Olney 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 USC00116446. 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: USC00116446. For informational purposes only.
Read our methodology — how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
