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Sioux City, Iowa climate
Dfa Hot-summer humid continental
Sioux City has a strongly seasonal cool-temperate climate (Hot-summer humid continental, Köppen Dfa). The hottest month is July with an average daily high near 87°F, while the coldest is January averaging around 10°F at night. Precipitation totals about 30 inches a year and is strongly seasonal — June alone averages 4.6 inches while January barely receives 0.63 inches.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)Sioux City climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 33 | 38 | 51 | 65 | 76 | 85 | 87 | 85 | 80 | 67 | 50 | 37 |
| Avg temp (°F) | 21 | 26 | 38 | 51 | 62 | 72 | 75 | 73 | 65 | 52 | 38 | 26 |
| Avg low (°F) | 10 | 15 | 25 | 36 | 48 | 59 | 62 | 60 | 51 | 38 | 25 | 15 |
| Precipitation (in) | 0.6 | 0.7 | 1.6 | 3.1 | 4.1 | 4.6 | 3.8 | 4.1 | 3.0 | 2.3 | 1.3 | 1.0 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 33 | 38 | 51 | 65 | 76 | 85 |
| Avg temp (°F) | 21 | 26 | 38 | 51 | 62 | 72 |
| Avg low (°F) | 10 | 15 | 25 | 36 | 48 | 59 |
| Precipitation (in) | 0.6 | 0.7 | 1.6 | 3.1 | 4.1 | 4.6 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 87 | 85 | 80 | 67 | 50 | 37 |
| Avg temp (°F) | 75 | 73 | 65 | 52 | 38 | 26 |
| Avg low (°F) | 62 | 60 | 51 | 38 | 25 | 15 |
| Precipitation (in) | 3.8 | 4.1 | 3.0 | 2.3 | 1.3 | 1.0 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 65 | 65 | 66 | 64 | 65 | 57 | 49 | 50 | 47 | 56 | 58 | 63 |
| Relative humidity (%) | 83 | 79 | 72 | 68 | 68 | 70 | 66 | 65 | 64 | 68 | 75 | 83 |
| Wind speed (mph) | 8.4 | 8.6 | 8.9 | 9.3 | 8.2 | 7.0 | 6.0 | 5.9 | 7.1 | 7.7 | 7.9 | 8.1 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 65 | 65 | 66 | 64 | 65 | 57 |
| Relative humidity (%) | 83 | 79 | 72 | 68 | 68 | 70 |
| Wind speed (mph) | 8.4 | 8.6 | 8.9 | 9.3 | 8.2 | 7.0 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 49 | 50 | 47 | 56 | 58 | 63 |
| Relative humidity (%) | 66 | 65 | 64 | 68 | 75 | 83 |
| Wind speed (mph) | 6.0 | 5.9 | 7.1 | 7.7 | 7.9 | 8.1 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Sioux Gateway/col Bud Day Field AP, a weather station, about 12 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.