Cairo, 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 Cairo's primary NOAA station, CAIRO 3N.
The climate verdict for Cairo
Water is the standout signal in Cairo, Illinois: 51.0 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 58°F. Its climate comfort score of 68/100 (good) lands mid-pack nationally, exceeding 56% of station-mapped location scores.
- 58°F
- average temperature, NOAA 1991-2020 normal
- 68/100
- comfort score, above 56% of station-mapped location scores
- 51.0"
- precipitation, annual total
- 212 days
- growing season, frost-free days
Cairo: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00093809 · Cairo, IL 58°F mean · 51.0" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-WET · SWING-MID · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 58°F
- RANK-UPPER #4,734
- PHOTO-FINISH ≈ Panhandle
- PRCP-WET 51.0"
- SWING-MID 45°F
- COMF-MID 68/100
- LOAD-HEAT 4,075 HDD
- STN-1 USW00093809
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Panhandle, TX ( -0.1 °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.
- Cairo (this station) 58°F
- Cold Panhandle, TX 58°F
- Hot W Paducah, KY 58°F
- Near Wupatki Nationa…, AZ 58°F
- Near Lakeside, MO 58°F
Climate Living Index · Cairo
Cairo: 69/100 · grade C
Cairo publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Cairo, 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 | 80 calendar days | 82/100 · B |
| Frost-free season | 212 days/year | 73/100 · B |
| Annual temperature balance | 58.1°F · 9.4° from 67.5°F | 70/100 · B |
| Precipitation balance | 51.0 in · 16.0 from 35 in | 43/100 · D |
Cairo · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Cairo is a temperate Köppen climate: Cfa
Coldest-month mean 34.7°F and warmest-month mean 79.2°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
- 79.2°F
- Coldest month
- 34.7°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 Cairo sits across the climate record
Three NOAA fields for Cairo's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 69th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Top 17% wettest
- Cairo's annual total ranks in the wetter third of 6,352 measured normals.
- Seasonal temperature swing
- 56th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Cairo compares across U.S. station-mapped locations
Cairo'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
Cairo's measured station temperature trend
MethodologyAcross 117 complete annual observations from 1878 to 2025, CAIRO 3N changed little at a fitted rate of 0.01°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Cairo primary station fitted change +0.01 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 43°F (6°C) | 26°F (-3°C) | 35°F (2°C) | 3.8" | 22.4 | 0.0 |
| February | 48°F (9°C) | 30°F (-1°C) | 39°F (4°C) | 3.9" | 17.5 | 0.0 |
| March | 59°F (15°C) | 38°F (3°C) | 48°F (9°C) | 4.8" | 9.5 | 0.0 |
| April | 70°F (21°C) | 48°F (9°C) | 59°F (15°C) | 5.4" | 1.2 | 0.3 |
| May | 78°F (26°C) | 58°F (14°C) | 68°F (20°C) | 5.1" | 0.0 | 1.5 |
| June | 86°F (30°C) | 66°F (19°C) | 76°F (24°C) | 4.4" | 0.0 | 8.4 |
| July | 89°F (32°C) | 70°F (21°C) | 79°F (26°C) | 4.1" | 0.0 | 15.0 |
| August | 88°F (31°C) | 68°F (20°C) | 78°F (25°C) | 3.2" | 0.0 | 12.5 |
| September | 82°F (28°C) | 60°F (15°C) | 71°F (21°C) | 3.5" | 0.0 | 3.9 |
| October | 71°F (22°C) | 48°F (9°C) | 59°F (15°C) | 4.1" | 1.2 | 0.1 |
| November | 58°F (14°C) | 37°F (3°C) | 48°F (9°C) | 4.5" | 9.5 | 0.0 |
| December | 47°F (8°C) | 30°F (-1°C) | 38°F (4°C) | 4.3" | 20.1 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 89°F around July 8, short of 90°F on every date, while 80 dates carry a normal low at or below freezing, the coldest 26°F near January 18.
The freezing stretch
The normal low stays at or below 32°F into February 24, then returns to freezing around December 7, covering 80 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.
The widest day
October 18 carries the biggest normal gap between afternoon and dawn, 24°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Cairo.
Where Cairo Stands Nationally
The normal water year runs well above the national norm at roughly 51 inches.
Cairo 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
Cairo 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 23%, with neither reaching the 35% that would mark a distinct wet season. Cairo has no dry season to plan around, though it does carry a 44.5°F seasonal spread.
The gap between the wettest and driest month still matters: April averages 5.4" and August 3.2". 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.
Frost Dates & Growing Season
First Fall Freeze
October 31
50% probability date
Last Spring Freeze
April 2
50% probability date
Growing Season
212 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,075
Higher = more heating needed
Cooling Degree Days
1,592
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IL closest to Cairo 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 (58°F here).
- Dickson, TN 58°F · 0.0°F off
- Henderson, TN 58°F · 0.0°F off
- Hillsboro, NM 58°F · 0.0°F off
- Marble Hill, MO 58°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (51.0" here), excluding temperature-peer places.
- Clinton, NC 51.0" · 0.0" off
- Conroe, TX 51.0" · 0.0" off
- Edenton, NC 51.0" · 0.0" off
- English, IN 51.0" · 0.0" off
Data-derived climate profile
How Cairo's climate pattern fits together
heating led · wet · mid swing
Cairo's energy balance leans toward cold weather: 4,075 annual heating degree days against 1,592 for cooling. Its 44.5°F seasonal range still makes the monthly rows more useful than the annual average alone.
Cairo's frost-free season lasts about 212 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 Cairo's middle-range seasonal profile. The measured spread is 44.5°F. The annual average is 58°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Alongside its heating load, Cairo carries 51.0 inches of precipitation in a normal year, inside PlainClimate's wet range. Snowfall is not added to the interpretation because its annual value is missing. 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 Cairo'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 Cairo, not an official NOAA class or a year-ahead forecast.
Questions about Cairo's climate
How much rain does Cairo get? ▼
How many days above 90°F does Cairo get? ▼
How much energy does heating and cooling require in Cairo? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Cairo's primary station: CAIRO 3N (USW00093809). 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 1710383). Match rule for Cairo: 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 Cairo 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.