Casey, IL Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Casey's primary NOAA station, CASEY.
The climate verdict for Casey
Water is the standout signal in Casey, Illinois: 45.5 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 54°F. Its climate comfort score of 68/100 (good) lands mid-pack nationally, exceeding 56% of station-mapped location scores.
- 54°F
- average temperature, NOAA 1991-2020 normal
- 68/100
- comfort score, above 56% of station-mapped location scores
- 45.5"
- annual precipitation · 12" snow
- 189 days
- frost-free days per growing season
Casey: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00111329 · Casey, IL 54°F mean · 45.5" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 54°F
- RANK-MID #3,911
- PHOTO-FINISH ≈ Robinson
- PRCP-MID 45.5"
- SWING-WIDE 48°F
- COMF-MID 68/100
- LOAD-HEAT 5,173 HDD
- STN-1 USC00111329
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Robinson, IL (+ 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.
- Casey (this station) 54°F
- Cold Independence, MO 54°F
- Hot Moberly, MO 54°F
- Near Robinson, IL 54°F
- Near Vandalia, IL 54°F
Climate Living Index · Casey
Casey: 61/100 · grade C
Casey publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Casey, not an official NOAA rating. Rankings still use Comfort Score 68/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 117 calendar days | 66/100 · C |
| Precipitation balance | 45.5 in · 10.5 from 35 in | 63/100 · C |
| Snowfall burden | 11.9 inches/year | 60/100 · C |
| Annual temperature balance | 54.1°F · 13.4° from 67.5°F | 56/100 · C |
| Frost-free season | 189 days/year | 56/100 · C |
Casey · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Casey is a continental Köppen climate: Dfa
Coldest-month mean 28.4°F and warmest-month mean 76.7°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
- 76.7°F
- Coldest month
- 28.4°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 Casey sits across the climate record
Three NOAA fields for Casey's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 57th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Top 30% wettest
- Casey's annual total ranks in the wetter third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 75%
- Warmest-to-coldest month gap for Casey is large versus 6,861 complete station-years.
How Casey compares across U.S. station-mapped locations
Casey'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 | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 38°F (3°C) | 19°F (-7°C) | 28°F (-2°C) | 3.3" | 5.0" | 26.3 | 0.0 |
| February | 43°F (6°C) | 22°F (-5°C) | 32°F (0°C) | 2.6" | 1.9" | 21.9 | 0.0 |
| March | 53°F (12°C) | 32°F (0°C) | 43°F (6°C) | 3.3" | 1.4" | 16.2 | 0.0 |
| April | 65°F (18°C) | 43°F (6°C) | 54°F (12°C) | 5.1" | 0.1" | 5.5 | 0.0 |
| May | 76°F (24°C) | 54°F (12°C) | 65°F (18°C) | 4.5" | 0.0" | 0.2 | 1.0 |
| June | 84°F (29°C) | 63°F (17°C) | 73°F (23°C) | 5.2" | 0.0" | 0.0 | 7.5 |
| July | 88°F (31°C) | 66°F (19°C) | 77°F (25°C) | 4.6" | 0.0" | 0.0 | 12.2 |
| August | 86°F (30°C) | 64°F (18°C) | 75°F (24°C) | 3.0" | 0.0" | 0.0 | 6.5 |
| September | 81°F (27°C) | 55°F (13°C) | 68°F (20°C) | 3.1" | 0.0" | 0.0 | 7.7 |
| October | 69°F (20°C) | 44°F (7°C) | 56°F (14°C) | 3.8" | 0.0" | 2.5 | 0.4 |
| November | 54°F (12°C) | 33°F (1°C) | 44°F (7°C) | 4.0" | 0.3" | 15.9 | 0.0 |
| December | 42°F (6°C) | 24°F (-4°C) | 33°F (1°C) | 3.1" | 3.2" | 23.3 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 88°F around July 22, short of 90°F on every date, while 117 dates carry a normal low at or below freezing, the coldest 19°F near January 16.
The freezing stretch
The normal low stays at or below 32°F into March 16, then returns to freezing around November 21, covering 117 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 4, when 41% of years recorded at least a hundredth of an inch. The driest is August 29 at 21%. Summed across the calendar, that is about 109 wet dates a year.
The widest day
September 28 carries the biggest normal gap between afternoon and dawn, 26°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Casey.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 5.0"
8.8 days with precipitation
Snow: 1.9"
8.1 days with precipitation
Snow: 1.4"
9.5 days with precipitation
Snow: 0.1"
11.0 days with precipitation
12.2 days with precipitation
11.0 days with precipitation
8.2 days with precipitation
6.6 days with precipitation
6.5 days with precipitation
8.6 days with precipitation
Snow: 0.3"
8.4 days with precipitation
Snow: 3.2"
9.3 days with precipitation
Casey spreads its precipitation across the year
Neither half of the year dominates here: June through August take 28% of the annual total and December through February 20%, with neither reaching the 35% that would mark a distinct wet season. Casey has no dry season to plan around, though it does carry a wide 48.3°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: June averages 5.2" and February 2.6". The three wettest months together take 33% 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 Casey, it arrives in quantity
45.5" of precipitation falls across only about 108 wet days here, averaging 0.42 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 108 a year, 30% of all days
- Average depth per wet day
- 0.42 inches
- Most wet days
- May, about 12
- Fewest wet days
- September, about 7
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 Casey, but rarely amounts to much
The normals record 11.9 inches of snow a year here, most likely in January. 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 8 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 20
50% probability date
Last Spring Freeze
April 14
50% probability date
Growing Season
189 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,173
Higher = more heating needed
Cooling Degree Days
1,228
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IL closest to Casey 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 (54°F here).
- Brunswick, MO 54°F · 0.0°F off
- Cole Camp, MO 54°F · 0.0°F off
- Columbus, IN 54°F · 0.0°F off
- Drain, OR 54°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (45.5" here), excluding temperature-peer places.
- Ridgway, PA 45.5" · 0.0" off
- Danforth, ME 45.6" · 0.0" off
- Bonham, TX 45.5" · 0.0" off
- Richmond, VA 45.5" · 0.0" off
Data-derived climate profile
How Casey's climate pattern fits together
heating led · wet · mid swing
Casey's energy balance leans toward cold weather: 5,173 annual heating degree days against 1,228 for cooling. Its 48.3°F seasonal range still makes the monthly rows more useful than the annual average alone.
Casey'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 Casey's middle-range seasonal profile. The measured spread is 48.3°F. The annual average is 54°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Alongside its heating load, Casey carries 45.5 inches of precipitation in a normal year, inside PlainClimate's wet range. Annual snowfall totals 11.9 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 Casey'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 Casey, not an official NOAA class or a year-ahead forecast.
Questions about Casey's climate
How much rain does Casey get? ▼
How many days above 90°F does Casey get? ▼
How much energy does heating and cooling require in Casey? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Casey's primary station: CASEY (USC00111329). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 1711618). Match rule for Casey: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Casey 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.