Carbondale, IL

Illinois · Records since 1898–2026

☁️ 79°F Feels like 87°
Currently in Carbondale
As of 1:00 PM CDT

Records for September 11

🔥 Record High

100°F

September 11, 1925

+18° from 82° normal

❄ Record Low

36°F

September 11, 1940

-22° from 58° normal
🌞 Normal high: 82°F 🌑 Normal low: 58°F 1991–2020 normals

All-Time Records — Carbondale

🔥
113°F
Hottest Day Ever
Aug 9, 1930
❄
-25°F
Coldest Day Ever
Jan 11, 1977
🌧
5.85"
Wettest Day Ever
Mar 18, 2008
☃
10.0"
Most Snow in One Day
Feb 26, 1979

First & Last Dates — Carbondale

How early and how late each seasonal turning point has ever arrived, across the full period of record

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Range ever recorded Normal date (1991–2020)
232 days
Longest growing season
2025
145 days
Shortest growing season
1940
190 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 100°F September 11, 1925
2 99°F September 11, 1953
3 99°F September 11, 1938
4 98°F September 11, 1927
5 98°F September 11, 1912
6 97°F September 11, 1936
7 96°F September 11, 1983
8 95°F September 11, 2013
9 95°F September 11, 1952
10 95°F September 11, 1915

Top 5 Record Lows — September 11

# Temp Date
🥶 36°F September 11, 1940
2 40°F September 11, 1917
3 42°F September 11, 1976
4 44°F September 11, 2017
5 45°F September 11, 1993
About this data — Records are sourced from the NOAA Threadex dataset via RCC ACIS, a quality-controlled record for long-term climate stations. Threadex adjusts for station relocations and observation-time changes, making records comparable across all years since 1898–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Carbondale

threshold: 96°F (90th percentile of historical Jun–Aug highs)
5.2
Avg heat wave length
days (historical)
101°
Avg peak temp
during heat waves
45
Dangerous nights 2026
Overnights ≥ 70°F
1
Heat waves 2026
so far

Days ≥ 90°F Per Year

1899–2026
38
2026 so far
50
Avg/year 1970–2025
40
Avg/year (last 10 complete)
95
Most in a year (1936)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Carbondale

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 9, 1936 – Aug 29, 1936 21 110°F (Aug 18) 103°F 74°F
2 Jul 25, 1930 – Aug 10, 1930 17 113°F (Aug 9) 104°F 72°F
3 Jul 15, 1901 – Jul 29, 1901 15 112°F (Jul 22) 104°F 71°F
4 Aug 28, 1912 – Sep 11, 1912 15 103°F (Sep 10) 100°F 68°F
5 Jun 21, 1901 – Jul 4, 1901 14 101°F (Jun 22) 99°F 73°F
6 Jul 6, 1936 – Jul 18, 1936 13 112°F (Jul 14) 103°F 74°F
7 Aug 31, 1925 – Sep 11, 1925 12 108°F (Sep 4) 104°F 68°F
8 Jun 27, 2012 – Jul 8, 2012 12 107°F (Jun 29) 104°F 71°F
9 Jul 5, 1914 – Jul 16, 1914 12 106°F (Jul 12) 102°F 70°F
10 Jun 28, 1911 – Jul 9, 1911 12 104°F (Jul 4) 100°F 70°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

Nights where the overnight low exceeded the 1991–2020 normal low

55
2026 total
above-normal nights
43.8
Avg / summer
1970–2020
74
Most in a summer
2016

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Annual totals and trend across the full period of record · see this year's standing →

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1898–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1898, annual totals have trended +0.36" per decade, about +4.5" across the record.

Heavy Rain Days Per Year (≥ 1.0")

Compare year-to-year changes in days with heavy rainfall (≥ 1.0")

This Year — 2026

How Carbondale is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

145 of 252 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

25.86"
2026 YTD
Normal: 31.54"
-5.68"
0.00"
September so far
September normal: 2.85"
-2.85"
4
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Carbondale is 5.68" behind the normal pace

Period Review — Aug 11 – Sep 10, 2026

Any window, evaluated against every other year on record — 31 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
79.7°F
Average temperature
7th-warmest of 119
+5.1°
vs. average
Normal: 74.6°F (1991–2020)

Average Temperature by Year — Aug 11 – Sep 10

1900–2026 · 2026 highlighted · trend -0.20° per decade (cooling since 1900)

Precipitation by Year — Aug 11 – Sep 10

1901–2025 · 2026 highlighted · trend -0.13" per decade (drier since 1901)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1936 84.2°F
2 1912 81.6°F
3 1925 81.5°F
4 1900 81.2°F
5 1913 81.1°F
6 1947 81.0°F
7 2007 79.7°F
8 2026 79.7°F
9 1937 79.6°F
10 1938 79.5°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1967 69.1°F
2 1904 69.2°F
3 1994 70.0°F
4 1982 70.3°F
5 2017 70.5°F
6 1992 70.9°F
7 1950 71.2°F
8 2009 71.5°F
9 1979 71.7°F
10 1981 71.7°F
About this data. Pick any start and end date and this becomes the same kind of review as the Month and Fall tabs, just for exactly the window you asked for — the generalized version of the same engine, evaluated across every year on record. Average temperature is the mean of each day's (high + low) / 2; precipitation is the sum of daily totals. A year missing more than about a fifth of the window's days is excluded from the temperature ranking; any missing day excludes a year from the precipitation ranking, since an unreported day is unreported rain. Ranges that cross from December into January aren't supported yet. Normals are the 1991–2020 mean for the same window.
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