Climate Comfort Score
68/100
Good
NOAA 1991–2020 normals 50°F annual avg Public-domain federal data
Illinois City Dam, IL Climate
Average temperature, precipitation, and a comfort score, drawn from NOAA NCEI 1991–2020 normals →
- 50°F
- Avg annual temp
- 68/100
- Comfort score
- 36.4"
- Annual precip
- 189d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Illinois City Dam
Illinois City Dam, Illinois averages 50°F a year and scores 68/100 on the comfort index - good, milder than 58% of U.S. cities.
- 50°F
- average temperature, NOAA 1991-2020 normal
- 68/100
- comfort score, milder than 58% of U.S. cities
- 36.4"
- yearly precipitation total
- 189 days
- frost-free days per growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
50°F (10°C)
Avg High
60°F
Avg Low
41°F
Annual Precip
36.4"
Comfort Score
68/100
Good
Avg Annual Temperature
50°F
30-year mean (NOAA NCEI)
Annual Precipitation
36.4"
Liquid-equivalent total
Comfort score vs national 100-point ceiling (Illinois City Dam) 68.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Good for the Illinois City Dam area.
How Illinois City Dam compares to every U.S. city
Illinois City Dam's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
68 Top 42% higher than 58% 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 Illinois City Dam
MethodologyIllinois City Dam'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 | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 31°F (-1°C) | 13°F (-10°C) | 22°F (-6°C) | 1.2" | 29.5 | 0.0 |
| February | 35°F (2°C) | 17°F (-8°C) | 26°F (-3°C) | 1.6" | 26.4 | 0.0 |
| March | 48°F (9°C) | 30°F (-1°C) | 39°F (4°C) | 2.3" | 19.6 | 0.0 |
| April | 61°F (16°C) | 39°F (4°C) | 50°F (10°C) | 3.5" | 6.0 | 0.0 |
| May | 72°F (22°C) | 51°F (11°C) | 62°F (17°C) | 4.8" | 0.4 | 1.2 |
| June | 81°F (27°C) | 62°F (16°C) | 71°F (22°C) | 5.0" | 0.0 | 4.4 |
| July | 85°F (29°C) | 65°F (18°C) | 75°F (24°C) | 4.0" | 0.0 | 8.1 |
| August | 83°F (28°C) | 63°F (17°C) | 73°F (23°C) | 3.9" | 0.0 | 4.9 |
| September | 77°F (25°C) | 55°F (13°C) | 66°F (19°C) | 3.6" | 0.0 | 1.7 |
| October | 64°F (18°C) | 43°F (6°C) | 54°F (12°C) | 2.8" | 4.0 | 0.2 |
| November | 49°F (9°C) | 31°F (-1°C) | 40°F (4°C) | 2.1" | 17.7 | 0.0 |
| December | 36°F (2°C) | 20°F (-7°C) | 28°F (-2°C) | 1.7" | 27.0 | 0.0 |
Monthly Precipitation
Average monthly rainfall
January 1.2"
11.1 days with precipitation
February 1.6"
9.9 days with precipitation
March 2.3"
11.9 days with precipitation
April 3.5"
12.4 days with precipitation
May 4.8"
13.8 days with precipitation
June 5.0"
12.7 days with precipitation
July 4.0"
9.6 days with precipitation
August 3.9"
9.8 days with precipitation
September 3.6"
8.7 days with precipitation
October 2.8"
10.1 days with precipitation
November 2.1"
9.4 days with precipitation
December 1.7"
11.2 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
October 24
50% probability date
Last Spring Freeze
April 18
50% probability date
Growing Season
189 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,221
Higher = more heating needed
Cooling Degree Days
951
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
What Illinois City Dam's climate means for you
Illinois City Dam runs 50°F a year - peaking in July, coldest in January.
- Gardeners get about 189 frost-free days, with the last spring freeze near April 18 - plan the planting calendar around it, not the regional average.
- Energy bills track 6,221 heating and 951 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: Illinois City Dam, IL
Based on station USC00114355 feeding NOAA's 1991–2020 climate normals, Illinois City Dam, Illinois averages 50°F a year, ranging from a mean daily high of 60°F to a mean daily low of 41°F. July is typically the warmest month of the year, while January is the coldest. Because these figures are thirty-year averages rather than any single year's readings, they describe the typical month, not a forecast for it.
Illinois City Dam averages 36.4 inches of precipitation a year, predominantly as rainfall, and that matters as much to daily life here as temperature does. The frost-free season averages 189 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 18 and the first fall freeze near October 24. As for energy demand, 6,221 heating degree days and 951 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Illinois City Dam scores 68/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Shoulder seasons bring the mildest highs and lows in the monthly tables above, summer brings July-driven heat, and winter brings January-driven cold - use that rhythm for planning. These figures are thirty-year averages rather than forecasts, so a specific year may still run warmer, cooler, wetter, or drier than what's shown.
Frequently Asked Questions
What is the average temperature in Illinois City Dam, IL? ▼
The average annual temperature in Illinois City Dam, Illinois is 50°F. The warmest month averages 85°F (29°C) and the coldest averages 13°F (-10°C).
How much rain does Illinois City Dam get? ▼
Illinois City Dam receives 36.4 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Illinois City Dam? ▼
Illinois City Dam has a climate comfort score of 68/100 (Good), milder than 58% of U.S. cities in the PlainClimate database.
When is the growing season in Illinois City Dam? ▼
Illinois City Dam has approximately 189 frost-free days per year, with the last spring freeze around April 18 and the first fall freeze around October 24.
How much energy does heating and cooling require in Illinois City Dam? ▼
Illinois City Dam has 6,221 heating degree days and 951 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 Illinois City Dam climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00114355 near Illinois City Dam.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00114355. 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.