Waterloo Weather in August
Average highs run from 83°F on August 1 to 78°F on August 31, and lows from 61°F to 56°F. Normal precipitation for the month is 4.14 in over about 10 wet days.
August day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
August at a glance
- Average high
- 81°F
- Average low
- 59°F
- Precipitation
- 4.14 in
- Record high
- 103°FAug 16, 1937
- Record low
- 34°FAug 30, 1893
- Chance of a freeze
- 0%
- Days of 90°F or more
- 1.8
- Daylight
- 14 h 31 min to 13 h 13 min
- Cloud cover
- 54%
- Humidity
- 74%
- Dew point
- 61°F
- Wind
- 8.1 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Aug 1 | 83°F | 61°F | 97°F 1939 | 46°F 1893 | 31% | 0% |
| Aug 2 | 82°F | 61°F | 102°F 1988 | 45°F 1907 | 31% | 0% |
| Aug 3 | 82°F | 61°F | 99°F 1988 | 41°F 1894 | 31% | 0% |
| Aug 4 | 82°F | 61°F | 100°F 1947 | 44°F 1971 | 31% | 0% |
| Aug 5 | 82°F | 61°F | 99°F 1947 | 43°F 1957 | 31% | 0% |
| Aug 6 | 82°F | 60°F | 101°F 1947 | 38°F 1893 | 32% | 0% |
| Aug 7 | 82°F | 60°F | 96°F 1937 | 36°F 1893 | 32% | 0% |
| Aug 8 | 82°F | 60°F | 97°F 1941 | 38°F 1904 | 32% | 0% |
| Aug 9 | 82°F | 60°F | 95°F 1936 | 44°F 1964 | 32% | 0% |
| Aug 10 | 82°F | 60°F | 99°F 1944 | 48°F 1967 | 32% | 0% |
| Aug 11 | 82°F | 60°F | 100°F 1941 | 42°F 1904 | 32% | 0% |
| Aug 12 | 81°F | 60°F | 95°F 1947 | 42°F 1893 | 32% | 0% |
| Aug 13 | 81°F | 60°F | 97°F 1944 | 41°F 1893 | 33% | 0% |
| Aug 14 | 81°F | 60°F | 98°F 1944 | 41°F 1964 | 33% | 0% |
| Aug 15 | 81°F | 60°F | 98°F 1936 | 41°F 1979 | 33% | 0% |
| Aug 16 | 81°F | 60°F | 103°F 1937 | 42°F 1979 | 33% | 0% |
| Aug 17 | 81°F | 59°F | 101°F 1988 | 45°F 1893 | 33% | 0% |
| Aug 18 | 81°F | 59°F | 102°F 1988 | 43°F 1963 | 33% | 0% |
| Aug 19 | 80°F | 59°F | 100°F 1947 | 45°F 1897 | 34% | 0% |
| Aug 20 | 80°F | 59°F | 101°F 1983 | 39°F 1893 | 34% | 0% |
| Aug 21 | 80°F | 59°F | 98°F 1947 | 40°F 1893 | 34% | 0% |
| Aug 22 | 80°F | 59°F | 100°F 1947 | 42°F 2024 | 34% | 0% |
| Aug 23 | 79°F | 58°F | 101°F 1947 | 42°F 1902 | 34% | 0% |
| Aug 24 | 79°F | 58°F | 102°F 1947 | 41°F 1908 | 34% | 0% |
| Aug 25 | 79°F | 58°F | 96°F 1948 | 37°F 1958 | 34% | 0% |
| Aug 26 | 79°F | 58°F | 97°F 1948 | 42°F 1917 | 34% | 0% |
| Aug 27 | 79°F | 57°F | 97°F 1937 | 40°F 1915 | 34% | 0% |
| Aug 28 | 78°F | 57°F | 95°F 1926 | 40°F 1893 | 35% | 0% |
| Aug 29 | 78°F | 57°F | 96°F 1984 | 38°F 1965 | 35% | 0% |
| Aug 30 | 78°F | 57°F | 95°F 1937 | 34°F 1893 | 34% | 0% |
| Aug 31 | 78°F | 56°F | 96°F 1937 | 36°F 1893 | 34% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- August 1
- sunrise 5:46 AM, sunset 8:17 PM
- August 31
- sunrise 6:19 AM, sunset 7:32 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00478910 (Waterloo Wwtp), public domain. Records: NOAA GHCN-Daily, station USC00478919, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.