Brookport 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 Brookport Dam's primary NOAA station, BROOKPORT DAM 52.
The climate verdict for Brookport Dam
Water is the standout signal in Brookport Dam, Illinois: 49.1 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 57°F. It scores 83/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 81% of them.
- 57°F
- yearly average temperature, NOAA normal
- 83/100
- comfort score, above 81% of station-mapped location scores
- 49.1"
- annual precipitation · 3" snow
- 204 days
- frost-free days per growing season
Brookport Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00110993 · Brookport Dam, IL 57°F mean · 49.1" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-MID · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 57°F
- RANK-UPPER #4,597
- PHOTO-FINISH ≈ Boonville
- PRCP-MID 49.1"
- SWING-MID 44°F
- COMF-TOP 83/100
- LOAD-HEAT 4,267 HDD
- STN-1 USC00110993
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Boonville, IN (+ 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.
- Brookport Dam (this station) 57°F
- Cold Smithland L&d, IL 57°F
- Hot Elkton, KY 57°F
- Near Boonville, IN 57°F
- Near Marcus Hook, PA 57°F
Climate Living Index · Brookport Dam
Brookport Dam: 68/100 · grade C
Brookport Dam publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Brookport Dam, not an official NOAA rating. Rankings still use Comfort Score 83/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 94 calendar days | 78/100 · B |
| Snowfall burden | 3.1 inches/year | 74/100 · B |
| Annual temperature balance | 57.3°F · 10.2° from 67.5°F | 67/100 · C |
| Frost-free season | 204 days/year | 67/100 · C |
| Precipitation balance | 49.1 in · 14.1 from 35 in | 50/100 · D |
Brookport Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Brookport Dam is a temperate Köppen climate: Cfa
Coldest-month mean 34.1°F and warmest-month mean 78.4°F place this station in temperate, no dry season, hot summer climates (Cfa). Class Cfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, no dry season, hot summer.
- Köppen code
- Cfa
- Group
- Temperate
- Warmest month
- 78.4°F
- Coldest month
- 34.1°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 Brookport Dam sits across the climate record
Three NOAA fields for Brookport Dam's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 67th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Top 21% wettest
- Brookport Dam's annual total ranks in the wetter third of 6,352 measured normals.
- Seasonal temperature swing
- 55th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Brookport Dam compares across U.S. station-mapped locations
Brookport Dam's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
83 Top 19% score exceeds 81% 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%). Below this entry.
- 70–80: 650 station-mapped locations (11%). Below this entry.
- 80–90: 921 station-mapped locations (15%). This entry sits in this band.
- 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 | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 43°F (6°C) | 25°F (-4°C) | 34°F (1°C) | 3.7" | 0.7" | 22.8 | 0.0 |
| February | 48°F (9°C) | 28°F (-2°C) | 38°F (3°C) | 3.8" | 1.8" | 17.5 | 0.0 |
| March | 58°F (14°C) | 36°F (2°C) | 47°F (8°C) | 4.6" | 0.1" | 11.2 | 0.0 |
| April | 69°F (21°C) | 46°F (8°C) | 58°F (14°C) | 5.1" | 0.0" | 1.9 | 0.0 |
| May | 77°F (25°C) | 56°F (13°C) | 67°F (19°C) | 4.8" | 0.0" | 0.0 | 0.7 |
| June | 85°F (30°C) | 65°F (18°C) | 75°F (24°C) | 4.7" | 0.0" | 0.0 | 8.4 |
| July | 89°F (31°C) | 68°F (20°C) | 78°F (26°C) | 3.9" | 0.0" | 0.0 | 14.7 |
| August | 88°F (31°C) | 66°F (19°C) | 77°F (25°C) | 2.9" | 0.0" | 0.0 | 12.7 |
| September | 82°F (28°C) | 59°F (15°C) | 70°F (21°C) | 3.5" | 0.0" | 0.0 | 4.9 |
| October | 71°F (22°C) | 47°F (8°C) | 59°F (15°C) | 4.1" | 0.0" | 1.3 | 0.1 |
| November | 57°F (14°C) | 36°F (2°C) | 47°F (8°C) | 4.0" | 0.0" | 10.1 | 0.0 |
| December | 47°F (8°C) | 29°F (-2°C) | 38°F (3°C) | 4.0" | 0.5" | 18.4 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 89°F around July 22, short of 90°F on every date, while 94 dates carry a normal low at or below freezing, the coldest 25°F near January 21.
The freezing stretch
The normal low stays at or below 32°F into March 2, then returns to freezing around November 30, covering 94 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 April 24, when 37% of years recorded at least a hundredth of an inch. The driest is August 22 at 21%. Summed across the calendar, that is about 104 wet dates a year.
The widest day
October 4 carries the biggest normal gap between afternoon and dawn, 25°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Brookport Dam.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 0.7"
8.5 days with precipitation
Snow: 1.8"
8.3 days with precipitation
Snow: 0.1"
10.2 days with precipitation
10.8 days with precipitation
10.7 days with precipitation
8.2 days with precipitation
7.9 days with precipitation
6.3 days with precipitation
6.8 days with precipitation
7.3 days with precipitation
8.4 days with precipitation
Snow: 0.5"
9.7 days with precipitation
Brookport Dam spreads its precipitation across the year
Neither half of the year dominates here: June through August take 23% of the annual total and December through February 24%, with neither reaching the 35% that would mark a distinct wet season. Brookport Dam has no dry season to plan around, though it does carry a 44.3°F seasonal spread.
The gap between the wettest and driest month still matters: April averages 5.1" and August 2.9". The three wettest months together take 30% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
When it rains in Brookport Dam, it arrives in quantity
49.1" of precipitation falls across only about 103 wet days here, averaging 0.48 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 103 a year, 28% of all days
- Average depth per wet day
- 0.48 inches
- Most wet days
- April, about 11
- Fewest wet days
- August, about 6
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Snow reaches Brookport Dam, but rarely amounts to much
The normals record 3.1 inches of snow a year here, most likely in February. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation; about 2 days a year record any measurable snow at all.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
October 27
50% probability date
Last Spring Freeze
April 6
50% probability date
Growing Season
204 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,267
Higher = more heating needed
Cooling Degree Days
1,481
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IL closest to Brookport 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 (57°F here).
- Ash Grove, MO 57°F · 0.0°F off
- Asheville, NC 57°F · 0.0°F off
- Bentonville, AR 57°F · 0.0°F off
- Bishop, CA 57°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (49.1" here), excluding temperature-peer places.
- Lenox Dale, MA 49.1" · 0.0" off
- Little Valley, NY 49.1" · 0.0" off
- Walton, NY 49.1" · 0.0" off
- Clintwood, VA 49.2" · 0.1" off
Data-derived climate profile
How Brookport Dam's climate pattern fits together
heating led · wet · mid swing
Brookport Dam's energy balance leans toward cold weather: 4,267 annual heating degree days against 1,481 for cooling. Its 44.3°F seasonal range still makes the monthly rows more useful than the annual average alone.
Brookport Dam's frost-free season lasts about 204 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 Brookport Dam's middle-range seasonal profile. The measured spread is 44.3°F. The annual average is 57°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Alongside its heating load, Brookport Dam carries 49.1 inches of precipitation in a normal year, inside PlainClimate's wet range. Annual snowfall totals 3.1 inches. That distinction matters because a wet annual total can arrive as rain, snow, or a mixture at different times.
These labels group NOAA 1991-2020 normals from Brookport 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 Brookport Dam, not an official NOAA class or a year-ahead forecast.
Questions about Brookport Dam's climate
How much rain does Brookport Dam get? ▼
How many days above 90°F does Brookport Dam get? ▼
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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 Brookport Dam's primary station: BROOKPORT DAM 52 (USC00110993). 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 Brookport 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 Brookport 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.