Illinois City Dam, IL Climate: Temperature & Rain by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Illinois City Dam's primary NOAA station, ILLINOIS CITY DAM 16.
The climate verdict for Illinois City Dam
Illinois City Dam, Illinois has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 50°F. Its climate comfort score of 68/100 (good) lands mid-pack nationally, exceeding 56% of station-mapped location scores.
- 50°F
- average temperature, NOAA 1991-2020 normal
- 68/100
- comfort score, above 56% of station-mapped location scores
- 36.4"
- yearly precipitation total
- 189 days
- frost-free days per growing season
Illinois City Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00114355 · Illinois City Dam, IL 50°F mean · 36.4" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 50°F
- RANK-MID #2,882
- PHOTO-FINISH ≈ Brewster
- PRCP-MID 36.4"
- SWING-WIDE 53°F
- COMF-MID 68/100
- LOAD-HEAT 6,221 HDD
- STN-1 USC00114355
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Brewster, KS (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every IL station list.
- Hot Ogallala, NE 51°F
- Near Muscatine, IA 51°F
- Illinois City D… (this station) 50°F
- Cold Rock Island L&d, IL 50°F
- Near Brewster, KS 50°F
Climate Living Index · Illinois City Dam
Illinois City Dam: 59/100 · grade C
Illinois City Dam publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Illinois City Dam, not an official NOAA rating. Rankings still use Comfort Score 68/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 36.4 in · 1.4 from 35 in | 93/100 · A |
| Normal heat + freeze calendar | 132 calendar days | 58/100 · C |
| Frost-free season | 189 days/year | 56/100 · C |
| Annual temperature balance | 50.4°F · 17.1° from 67.5°F | 42/100 · D |
Illinois City Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Illinois City Dam is a continental Köppen climate: Dfa
Coldest-month mean 22.0°F and warmest-month mean 74.9°F place this station in continental, no dry season, hot summer climates (Dfa). Class Dfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, hot summer.
- Köppen code
- Dfa
- Group
- Continental
- Warmest month
- 74.9°F
- Coldest month
- 22.0°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Illinois City Dam sits across the climate record
Three NOAA fields for Illinois City Dam's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 42nd percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 50th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Wider than 88%
- Warmest-to-coldest month gap for Illinois City Dam is large versus 6,861 complete station-years.
How Illinois City Dam compares across U.S. station-mapped locations
Illinois City Dam's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
68 Top 44% score exceeds 56% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). This entry sits in this band.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
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 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 85°F around July 21, short of 90°F on every date, while 132 dates carry a normal low at or below freezing, the coldest 13°F near January 20.
The freezing stretch
The normal low stays at or below 32°F into March 22, then returns to freezing around November 12, covering 132 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is May 27, when 45% of years recorded at least a hundredth of an inch. The driest is September 24 at 30%. Summed across the calendar, that is about 131 wet dates a year.
The widest day
April 18 carries the biggest normal gap between afternoon and dawn, 23°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Illinois City Dam.
Where Illinois City Dam Stands Nationally
Days and nights track unusually close together; the widest normal swing, about 23°F, is narrower than most stations record.
Illinois City Dam earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall
11.1 days with precipitation
9.9 days with precipitation
11.9 days with precipitation
12.4 days with precipitation
13.8 days with precipitation
12.7 days with precipitation
9.6 days with precipitation
9.8 days with precipitation
8.7 days with precipitation
10.1 days with precipitation
9.4 days with precipitation
11.2 days with precipitation
Illinois City Dam runs a summer-peaked wet season
36% of Illinois City Dam's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is June at 5.0", on a wide 52.9°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: June, May, July, taking 38% of the annual total between them.
- Driest month: January at 1.2".
- Winter share: 12% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
How Illinois City Dam's precipitation splits across the calendar
About 131 days a year record measurable precipitation here, carrying 36.4" between them, or roughly 0.28 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
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
Nationwide similar cities
Other rankable U.S. places outside IL closest to Illinois City Dam on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (50°F here).
- Alcalde, NM 50°F · 0.0°F off
- Beaver Falls, PA 50°F · 0.0°F off
- Brewster, KS 50°F · 0.0°F off
- Colorado Springs, CO 50°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (36.4" here), excluding temperature-peer places.
- Oakland, IA 36.4" · 0.0" off
- Clinton, IA 36.5" · 0.0" off
- Colo, IA 36.5" · 0.0" off
- Rockport, TX 36.4" · 0.0" off
Data-derived climate profile
How Illinois City Dam's climate pattern fits together
heating led · moderate · mid swing
Illinois City Dam's energy balance leans toward cold weather: 6,221 annual heating degree days against 951 for cooling. Its 52.9°F seasonal range still makes the monthly rows more useful than the annual average alone.
Illinois City Dam's frost-free season lasts about 189 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
July and January mark the typical warm and cold ends of the calendar in Illinois City Dam's middle-range seasonal profile. The measured spread is 52.9°F. The annual average is 50°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Illinois City Dam's 36.4 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Snowfall is not added to the interpretation because its annual value is missing. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Illinois City Dam's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Illinois City Dam, not an official NOAA class or a year-ahead forecast.
Questions about Illinois City Dam's climate
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Illinois City Dam's primary station: ILLINOIS CITY DAM 16 (USC00114355). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Illinois City Dam; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Illinois City Dam comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.