Sioux Falls, SD
South Dakota · Records since 1893–2026
Records for August 11
🔥 Record High
August 11, 1936
+15° from 84° normal❄ Record Low
August 11, 1902
-27° from 62° normalAll-Time Records — Sioux Falls
Top 10 Record Highs — August 11
| # | Temp | Date |
|---|---|---|
| 🏆 | 99°F | August 11, 1936 |
| 2 | 97°F | August 11, 1995 |
| 3 | 97°F | August 11, 1988 |
| 4 | 96°F | August 11, 1947 |
| 5 | 95°F | August 11, 1958 |
| 6 | 95°F | August 11, 1935 |
| 7 | 95°F | August 11, 1905 |
| 8 | 94°F | August 11, 1949 |
| 9 | 94°F | August 11, 1941 |
| 10 | 94°F | August 11, 1909 |
Top 5 Record Lows — August 11
| # | Temp | Date |
|---|---|---|
| 🥶 | 35°F | August 11, 1902 |
| 2 | 44°F | August 11, 1968 |
| 3 | 44°F | August 11, 1893 |
| 4 | 45°F | August 11, 1931 |
| 5 | 45°F | August 11, 1897 |
Heat Wave Summary — Sioux Falls
threshold: 93°F (90th percentile of historical Jun–Aug highs)2026 Daily High Temperature vs Normal
Year to date127 of 221 days with data were above the 1991–2020 normal high for their date.
Days ≥ 90°F Per Year
1893–2026Average Daily High by Decade
Full year · complete decades only
Longest Heat Waves — Sioux Falls
| # | Dates | Days | Peak | Avg High | Avg Overnight Low |
|---|---|---|---|---|---|
| 🏆 | Jul 2, 1936 – Jul 19, 1936 | 18 | 110°F (Jul 17) | 102°F | 73°F |
| 2 | Jun 17, 1910 – Jul 2, 1910 | 16 | 98°F (Jun 20) | 95°F | 66°F |
| 3 | Jul 13, 2012 – Jul 25, 2012 | 13 | 102°F (Jul 24) | 98°F | 72°F |
| 4 | Jul 17, 1940 – Jul 25, 1940 | 9 | 105°F (Jul 18) | 100°F | 71°F |
| 5 | Jul 28, 1955 – Aug 5, 1955 | 9 | 101°F (Jul 30) | 98°F | 73°F |
| 6 | Jul 16, 1974 – Jul 24, 1974 | 9 | 101°F (Jul 17) | 98°F | 70°F |
| 7 | Jul 25, 1987 – Aug 2, 1987 | 9 | 101°F (Jul 30) | 97°F | 72°F |
| 8 | Jul 26, 1988 – Aug 2, 1988 | 8 | 107°F (Jul 31) | 98°F | 69°F |
| 9 | Jun 28, 1966 – Jul 5, 1966 | 8 | 101°F (Jul 4) | 96°F | 70°F |
| 10 | Aug 13, 1972 – Aug 20, 1972 | 8 | 98°F (Aug 17) | 96°F | 72°F |
Heat Waves Per Year
Warm Summer Nights (Jun–Aug)
Nights where the overnight low exceeded the 1991–2020 normal low
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
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
Average temperature · July 2026
24th-warmest month on record
19th-warmest July of 134 on record
+3.7° vs. 73.4° average (1991–2020)Longest 90°F Streak in July
5 consecutive days with highs of at least 90°F (Jul 25–29, 2026, peaking at 97°F)
The longest July streak since 2023 (3 years). The July record is 18 days, set in 1936.
Average July Temperature by Year
1893–2026 · 2026 highlighted
Warmest Julys on Record
| # | Year | Avg Temp |
|---|---|---|
| 1 | 1936 | 84.5°F |
| 2 | 2012 | 81.3°F |
| 3 | 1935 | 80.7°F |
| 4 | 1901 | 79.9°F |
| 5 | 1955 | 79.5°F |
| 6 | 1974 | 79.2°F |
| 7 | 1916 | 78.9°F |
| 8 | 1966 | 78.7°F |
| 9 | 1957 | 78.6°F |
| 10 | 1975 | 78.5°F |
Warmest Months on Record (Any Month)
| # | Month | Avg Temp |
|---|---|---|
| 1 | July 1936 | 84.5°F |
| 2 | July 2012 | 81.3°F |
| 3 | July 1935 | 80.7°F |
| 4 | July 1901 | 79.9°F |
| 5 | July 1955 | 79.5°F |
| 6 | July 1974 | 79.2°F |
| 7 | July 1916 | 78.9°F |
| 8 | August 1947 | 78.8°F |
| 9 | July 1966 | 78.7°F |
| 10 | July 1957 | 78.6°F |
Nearby Stations — July 2026
How the same month ranked at the closest reporting stations
| Station | Avg Temp | July Rank |
|---|---|---|
| Sioux Falls, SD | 77.1°F | 19th of 134 |
| Mitchell, SD | 78.7°F | 17th of 127 |
| Sioux City, IA | 77.3°F | 33rd of 138 |
| Spencer, IA | 74.1°F | 47th of 110 |
| Huron, SD | 78.1°F | 14th of 146 |