Chicago, IL

Illinois · Records since 1872–2026

☀️ 76°F
Currently in Chicago
As of 1:15 PM CDT

Records for September 11

🔥 Record High

95°F

September 11, 1952

+18° from 77° normal

❄ Record Low

42°F

September 11, 1993

-17° from 59° normal
🌞 Normal high: 77°F 🌑 Normal low: 59°F 1991–2020 normals

All-Time Records — Chicago

🔥
105°F
Hottest Day Ever
Jul 24, 1934
❄
-27°F
Coldest Day Ever
Jan 20, 1985
🌧
6.86"
Wettest Day Ever
Jul 23, 2011
☃
18.6"
Most Snow in One Day
Jan 2, 1999

First & Last Dates — Chicago

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)
235 days
Longest growing season
1931
142 days
Shortest growing season
1981
180 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 95°F September 11, 1952
2 92°F September 11, 1908
3 92°F September 11, 1895
4 91°F September 11, 2013
5 91°F September 11, 1978
6 91°F September 11, 1961
7 91°F September 11, 1936
8 91°F September 11, 1931
9 90°F September 11, 2005
10 90°F September 11, 1953

Top 5 Record Lows — September 11

# Temp Date
🥶 42°F September 11, 1993
2 44°F September 11, 1943
3 45°F September 11, 1995
4 45°F September 11, 1917
5 46°F September 11, 1999
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 1872–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Chicago

threshold: 91°F (90th percentile of historical Jun–Aug highs)
3.9
Avg heat wave length
days (historical)
96°
Avg peak temp
during heat waves
31
Dangerous nights 2026
Overnights ≥ 70°F
3
Heat waves 2026
so far

Days ≥ 90°F Per Year

1872–2026
16
2026 so far
16
Avg/year 1970–2025
21
Avg/year (last 10 complete)
47
Most in a year (1988)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Chicago

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 25, 1953 – Sep 3, 1953 10 101°F (Sep 1) 98°F 71°F
2 Jul 26, 1955 – Aug 4, 1955 10 100°F (Jul 27) 96°F 76°F
3 Aug 19, 1959 – Aug 28, 1959 10 96°F (Aug 21) 94°F 74°F
4 Jul 27, 1988 – Aug 4, 1988 9 100°F (Aug 1) 97°F 72°F
5 Jul 17, 1987 – Jul 25, 1987 9 96°F (Jul 20) 93°F 71°F
6 Jun 30, 2012 – Jul 7, 2012 8 103°F (Jul 5) 98°F 75°F
7 Aug 17, 1947 – Aug 24, 1947 8 100°F (Aug 24) 97°F 74°F
8 Aug 22, 1948 – Aug 29, 1948 8 98°F (Aug 24) 95°F 72°F
9 May 16, 1977 – May 23, 1977 8 95°F (May 20) 92°F 70°F
10 Aug 4, 1900 – Aug 11, 1900 8 94°F (Aug 4) 93°F 75°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

52
2026 total
above-normal nights
35.8
Avg / summer
1970–2020
72
Most in a summer
1921

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 (1871–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1871, annual totals have trended +0.37" per decade, about +5.6" 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 Chicago is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

129 of 253 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

31.03"
2026 YTD
Normal: 27.83"
+3.20"
0.06"
September so far
September normal: 3.19"
-3.13"
10
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Chicago is 3.20" ahead of the normal pace

Period Review — Sep 1 – Nov 30, 2026

Any window, evaluated against every other year on record — 91 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
2026 is still under way for this window — totals and rankings appear once November 30 passes.

Average Temperature by Year — Sep 1 – Nov 30

1872–2025 · 2026 highlighted · trend +0.07° per decade (warming since 1872)

Precipitation by Year — Sep 1 – Nov 30

1871–2025 · 2026 highlighted · trend +0.05" per decade (wetter since 1871)

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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