Quincy, IL

Illinois · Records since 1901–2026

☁️ 79°F Feels like 86°
Currently in Quincy
As of 1:30 PM CDT

Records for September 11

🔥 Record High

99°F

September 11, 1936

+19° from 80° normal

❄ Record Low

41°F

September 11, 1940

-17° from 58° normal
🌞 Normal high: 80°F 🌑 Normal low: 58°F 1991–2020 normals

All-Time Records — Quincy

🔥
114°F
Hottest Day Ever
Jul 15, 1936
❄
-29°F
Coldest Day Ever
Feb 13, 1905
🌧
5.84"
Wettest Day Ever
Jun 14, 1950
☃
12.7"
Most Snow in One Day
Dec 25, 1915

First & Last Dates — Quincy

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)
239 days
Longest growing season
1929
149 days
Shortest growing season
1908
191 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 99°F September 11, 1936
2 98°F September 11, 1927
3 97°F September 11, 2013
4 97°F September 11, 1931
5 96°F September 11, 1933
6 95°F September 11, 1953
7 95°F September 11, 1912
8 94°F September 11, 2000
9 94°F September 11, 1938
10 94°F September 11, 1913

Top 5 Record Lows — September 11

# Temp Date
🥶 41°F September 11, 1940
2 41°F September 11, 1917
3 43°F September 11, 1967
4 44°F September 11, 1959
5 46°F September 11, 1958
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 1901–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Quincy

threshold: 95°F (90th percentile of historical Jun–Aug highs)
5.3
Avg heat wave length
days (historical)
101°
Avg peak temp
during heat waves
36
Dangerous nights 2026
Overnights ≥ 70°F
1
Heat waves 2026
so far

Days ≥ 90°F Per Year

1901–2026
23
2026 so far
35
Avg/year 1970–2025
28
Avg/year (last 10 complete)
90
Most in a year (1936)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Quincy

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 9, 1901 – Jul 28, 1901 20 111°F (Jul 22) 102°F 73°F
2 Aug 9, 1936 – Aug 28, 1936 20 109°F (Aug 24) 104°F 78°F
3 Jul 3, 1936 – Jul 20, 1936 18 114°F (Jul 15) 104°F 78°F
4 Jul 7, 1980 – Jul 20, 1980 14 105°F (Jul 14) 100°F 78°F
5 Jun 23, 1934 – Jul 6, 1934 14 104°F (Jun 28) 100°F 76°F
6 Jul 23, 1940 – Aug 5, 1940 14 104°F (Jul 25) 100°F 74°F
7 Aug 1, 1934 – Aug 12, 1934 12 111°F (Aug 9) 103°F 76°F
8 May 30, 1934 – Jun 9, 1934 11 103°F (May 30) 99°F 72°F
9 Jul 12, 1932 – Jul 22, 1932 11 100°F (Jul 19) 96°F 75°F
10 Aug 1, 1930 – Aug 10, 1930 10 106°F (Aug 9) 101°F 75°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

51
2026 total
above-normal nights
44.7
Avg / summer
1970–2020
77
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 (1901–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1901, annual totals have trended +0.04" per decade, about +0.5" 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 Quincy is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

32.98"
2026 YTD
Normal: 27.21"
+5.77"
0.93"
September so far
September normal: 3.09"
-2.16"
12
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Quincy is 5.77" 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

1901–2025 · 2026 highlighted · trend -0.13° per decade (cooling since 1901)

Precipitation by Year — Sep 1 – Nov 30

1901–2025 · 2026 highlighted · trend +0.03" per decade (wetter since 1901)

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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