Climate Comfort Score
63/100
Good
NOAA 1991–2020 normals 51°F annual avg Public-domain federal data
Chicago Ohare, IL Climate
Pulled from NOAA NCEI 1991–2020 normals →: average temperature, precipitation, and comfort score
- 51°F
- Avg annual temp
- 63/100
- Comfort score
- 37.9"
- Annual precip
- 195d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Chicago Ohare
Chicago Ohare, Illinois averages 51°F a year and scores 63/100 on the comfort index - good, milder than 47% of U.S. cities.
- 51°F
- annual average temperature (NOAA normal)
- 63/100
- comfort score, milder than 47% of U.S. cities
- 37.9"
- annual precipitation · 38" snow
- 195 days
- frost-free growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
51°F (11°C)
Avg High
60°F
Avg Low
43°F
Annual Precip
37.9"
Annual Snow
38.4"
Comfort Score
63/100
Good
Avg Annual Temperature
51°F
30-year mean (NOAA NCEI)
Annual Precipitation
37.9"
Plus 38.4" of snow
Comfort score vs national 100-point ceiling (Chicago Ohare) 63.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Good for the Chicago Ohare area.
How Chicago Ohare compares to every U.S. city
Chicago Ohare's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
63 Top 53% higher than 47% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for Chicago Ohare
MethodologyChicago Ohare's NOAA 1991-2020 normal sits inside a longer story: U.S. land temperatures have been tracking (and drifting from) the global mean since 1900, and the chart below shows that spread, with the most recent decade running 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 | 32°F (0°C) | 19°F (-7°C) | 25°F (-4°C) | 2.0" | 11.3" | 28.1 | 0.0 |
| February | 36°F (2°C) | 22°F (-6°C) | 29°F (-2°C) | 2.0" | 10.7" | 24.4 | 0.0 |
| March | 47°F (8°C) | 31°F (-1°C) | 39°F (4°C) | 2.5" | 5.5" | 19.9 | 0.0 |
| April | 59°F (15°C) | 40°F (5°C) | 50°F (10°C) | 3.8" | 1.3" | 6.0 | 0.0 |
| May | 71°F (21°C) | 51°F (10°C) | 61°F (16°C) | 4.5" | 0.0" | 0.2 | 0.8 |
| June | 80°F (27°C) | 61°F (16°C) | 71°F (21°C) | 4.1" | 0.0" | 0.0 | 4.1 |
| July | 85°F (29°C) | 66°F (19°C) | 75°F (24°C) | 3.7" | 0.0" | 0.0 | 6.5 |
| August | 83°F (28°C) | 65°F (18°C) | 74°F (23°C) | 4.3" | 0.0" | 0.0 | 3.7 |
| September | 76°F (24°C) | 57°F (14°C) | 66°F (19°C) | 3.2" | 0.0" | 0.1 | 1.6 |
| October | 63°F (17°C) | 45°F (7°C) | 54°F (12°C) | 3.4" | 0.2" | 2.7 | 0.0 |
| November | 48°F (9°C) | 34°F (1°C) | 41°F (5°C) | 2.4" | 1.8" | 14.5 | 0.0 |
| December | 37°F (3°C) | 24°F (-4°C) | 31°F (-1°C) | 2.1" | 7.6" | 25.4 | 0.0 |
Monthly Precipitation
Average monthly rainfall and snowfall
January 2.0"
Snow: 11.3"
11.0 days with precipitation
February 2.0"
Snow: 10.7"
9.4 days with precipitation
March 2.5"
Snow: 5.5"
10.8 days with precipitation
April 3.8"
Snow: 1.3"
12.3 days with precipitation
May 4.5"
12.5 days with precipitation
June 4.1"
11.1 days with precipitation
July 3.7"
9.7 days with precipitation
August 4.3"
9.4 days with precipitation
September 3.2"
8.5 days with precipitation
October 3.4"
Snow: 0.2"
10.5 days with precipitation
November 2.4"
Snow: 1.8"
10.0 days with precipitation
December 2.1"
Snow: 7.6"
10.6 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
October 28
50% probability date
Last Spring Freeze
April 16
50% probability date
Growing Season
195 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,974
Higher = more heating needed
Cooling Degree Days
1,003
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Humidity & Wind
Monthly averages from hourly observations
| Month | Humidity | Wind (mph) | Clear Sky % | Overcast % |
|---|---|---|---|---|
| January | 73% | 10.5 | 17% | 49% |
| February | 69% | 10.9 | 15% | 47% |
| March | 63% | 11.1 | 15% | 41% |
| April | 60% | 10.5 | 18% | 37% |
| May | 64% | 9.1 | 17% | 28% |
| June | 64% | 8.4 | 18% | 18% |
| July | 66% | 7.8 | 17% | 18% |
| August | 69% | 8.0 | 21% | 18% |
| September | 68% | 9.0 | 22% | 24% |
| October | 68% | 10.4 | 18% | 40% |
| November | 73% | 10.4 | 15% | 48% |
| December | 75% | 10.6 | 14% | 51% |
What Chicago Ohare's climate means for you
Chicago Ohare runs 51°F a year - peaking in July, coldest in January.
- Gardeners get about 195 frost-free days, with the last spring freeze near April 16 - plan the planting calendar around it, not the regional average.
- Energy bills track 5,974 heating and 1,003 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: Chicago Ohare, IL
An annual average temperature of 51°F, ranging from a mean daily high of 60°F to a mean daily low of 43°F is what the NOAA 1991–2020 climate normals report for Chicago Ohare, Illinois. July is typically the warmest month of the year, while January is the coldest. That baseline comes from station USW00094846 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.
Chicago Ohare averages 37.9 inches of precipitation a year, with 38.4 inches typically falling as snow, and that matters as much to daily life here as temperature does. The frost-free season averages 195 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 16 and the first fall freeze near October 28. As for energy demand, 5,974 heating degree days and 1,003 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Chicago Ohare scores 63/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above turn that into a planning tool: expect the mildest highs and lows in the shoulder seasons, July-driven heat at the peak of summer, and January-driven cold at the depth of winter. Every number here is a thirty-year average, not a forecast, so any given year can and does run warmer, cooler, wetter, or drier than the normal.
Frequently Asked Questions
What is the average temperature in Chicago Ohare, IL? ▼
The average annual temperature in Chicago Ohare, Illinois is 51°F. The warmest month averages 85°F (29°C) and the coldest averages 19°F (-7°C).
How much rain does Chicago Ohare get? ▼
Chicago Ohare receives 37.9 inches of precipitation annually, including 38.4 inches of snow. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Chicago Ohare? ▼
Chicago Ohare has a climate comfort score of 63/100 (Good), milder than 47% of U.S. cities in the PlainClimate database.
When is the growing season in Chicago Ohare? ▼
Chicago Ohare has approximately 195 frost-free days per year, with the last spring freeze around April 16 and the first fall freeze around October 28.
How much energy does heating and cooling require in Chicago Ohare? ▼
Chicago Ohare has 5,974 heating degree days and 1,003 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Chicago Ohare climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USW00094846 near Chicago Ohare.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USW00094846. 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
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.