Waterloo, IA

Iowa · Records since 1895–2026

☁️ 76°F Feels like 84°
Currently in Waterloo
As of 3:45 AM CDT

Records for August 11

🔥 Record High

99°F

August 11, 1905

+15° from 84° normal

❄ Record Low

43°F

August 11, 1982

-19° from 62° normal
🌞 Normal high: 84°F 🌑 Normal low: 62°F 1991–2020 normals

All-Time Records — Waterloo

🔥
112°F
Hottest Day Ever
Jul 14, 1936
-34°F
Coldest Day Ever
Jan 16, 2009
🌧
6.00"
Wettest Day Ever
Sep 8, 1941
14.0"
Most Snow in One Day
Nov 30, 1934

Top 10 Record Highs — August 11

# Temp Date
🏆 99°F August 11, 1905
2 98°F August 11, 1941
3 97°F August 11, 1923
4 96°F August 11, 1988
5 95°F August 11, 1935
6 95°F August 11, 1899
7 94°F August 11, 1947
8 94°F August 11, 1909
9 93°F August 11, 1995
10 92°F August 11, 2021

Top 5 Record Lows — August 11

# Temp Date
🥶 43°F August 11, 1982
2 45°F August 11, 1986
3 45°F August 11, 1967
4 46°F August 11, 2004
5 47°F August 11, 2012
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 1895–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Waterloo

threshold: 92°F (90th percentile of historical Jun–Aug highs)
4.5
Avg heat wave length
days (historical)
98°
Avg peak temp
during heat waves
8
Dangerous nights 2026
Overnights ≥ 70°F
0
Heat waves 2026
so far

2026 Daily High Temperature vs Normal

Year to date
Above normal Below normal

111 of 221 days with data were above the 1991–2020 normal high for their date.


Days ≥ 90°F Per Year

1895–2026
9
2026 so far
21
Avg/year 1970–2025
22
Avg/year (last 10 complete)
60
Most in a year (1936)

Average Daily High by Decade

Full year · complete decades only


Longest Heat Waves — Waterloo

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 9, 1901 – Jul 27, 1901 19 107°F (Jul 24) 100°F 70°F
2 Jul 3, 1936 – Jul 18, 1936 16 112°F (Jul 13) 104°F 71°F
3 Jun 22, 1934 – Jul 2, 1934 11 107°F (Jun 27) 100°F 69°F
4 Jul 21, 1916 – Jul 31, 1916 11 104°F (Jul 29) 99°F 68°F
5 Jun 22, 1931 – Jul 1, 1931 10 106°F (Jun 28) 103°F 74°F
6 Jul 26, 1955 – Aug 4, 1955 10 103°F (Jul 30) 98°F 74°F
7 May 28, 1934 – Jun 5, 1934 9 108°F (May 31) 100°F 66°F
8 Jul 27, 1988 – Aug 4, 1988 9 105°F (Jul 31) 98°F 68°F
9 Jul 23, 1919 – Jul 31, 1919 9 101°F (Jul 27) 96°F 68°F
10 Jul 14, 1931 – Jul 22, 1931 9 99°F (Jul 17) 97°F 67°F

Heat Waves Per Year


Warm Summer Nights (Jun–Aug)

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

34
2026 so far
above-normal nights
36.3
Avg / summer
1970–2020
56
Most in a summer
1943

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Actual vs. 1991–2020 full-month and full-season normals

27.84"
2026 YTD
Normal: 24.28"
+3.56"
1.66"
August so far
August normal: 4.17"
-2.51"
14.68"
Summer so far
Summer normal: 14.23"
+0.45"
10
2026 heavy rain days
Days with ≥ 1.0"

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1970–2026)

Blue = above average · tan = below average · gold = 2026 (partial)

Heavy Rain Days Per Year (≥ 1.0")

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

Month in Review — July 2026

75.8°F

Average temperature · July 2026

39th-warmest month on record

27th-warmest July of 132 on record

+2.5° vs. 73.3° average (1991–2020)
82.4°F
Warmest month ever
July 1936
82.4°F
Warmest July ever
1936
7
Days ≥ 90°F
in July
96°F
Hottest of 2026
Jul 26

Longest 90°F Streak in July

4 consecutive days with highs of at least 90°F (Jul 14–17, 2026, peaking at 92°F)

The longest July streak since 2023 (3 years). The July record is 19 days, set in 1901.


Average July Temperature by Year

1895–2026 · 2026 highlighted


Warmest Julys on Record

# Year Avg Temp
1 1936 82.4°F
2 1901 81.9°F
3 1916 80.7°F
4 2012 79.3°F
5 1935 79.3°F
6 1955 79.1°F
7 1921 78.6°F
8 1931 77.7°F
9 1934 77.6°F
10 2011 77.6°F

Warmest Months on Record (Any Month)

# Month Avg Temp
1 July 1936 82.4°F
2 July 1901 81.9°F
3 July 1916 80.7°F
4 August 1947 79.4°F
5 July 2012 79.3°F
6 July 1935 79.3°F
7 July 1955 79.1°F
8 July 1921 78.6°F
9 June 1934 78.4°F
10 August 1936 78.2°F

Nearby Stations — July 2026

How the same month ranked at the closest reporting stations

Station Avg Temp July Rank
Waterloo, IA 75.8°F 27th of 132
Cedar Rapids, IA 75.5°F 43rd of 132
Dubuque, IA 75.3°F 41st of 151
Des Moines, IA 78.4°F 29th of 148
Rochester, MN 74.2°F 11th of 113
About this data. Monthly averages are the mean of daily average temperatures, computed from NOAA Threadex records via RCC ACIS. Months missing more than three days of observations are excluded from the rankings, so the in-progress month never appears. Rankings cover 1573 complete months on record.