Photo: Jared Winkler · CC BY-SA 4.0Nights turn raw in Little Sioux each January, colder than in 91% of U.S. towns
Expect July afternoons of about 86°. From frosty January to warm July, readings climb 74°. By precipitation alone, it ranks drier than 85% of U.S. towns. Tender plants can go out after about May 1; in half of years the first frost comes by October 3.
A year in Little Sioux at a glance
Each month’s typical high and low, and what it brings.
What stands out about Little Sioux’s climate
Compared with towns across the U.S., with Little Sioux’s place in Iowa beside it.
What a year in Little Sioux feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 155 frost-free days a year
In half of years the last 32° night comes by May 1 and the first by October 3. Frost and day counts come from NOAA’s station at Little Sioux 2 Nw, IA, 1.7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Little Sioux’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 46 inches of snow a winter
Snow, measured at Little Sioux 2 Nw, IA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 31 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 114 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Little Sioux
89% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Little Sioux 2 Nw, IA.
Living with Little Sioux’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
155 frost-free days in zone 5a. The last frost comes by May 1 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 3.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Little Sioux from natural hazards, river flooding is the largest share (49%); heat waves, cold waves, winter storms and ice storms together are 5%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Little Sioux and similar climates
TownRatings has no climate map of the towns around Little Sioux yet.
Climates most like Little Sioux’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Little Sioux, IA | 12° | 86° | 31" | 46" |
| Mitchell, SD | 8° | 86° | 25" | 41" |
| Rock Island, IL | 14° | 85° | 37" | 36" |
| Milan, MI | 17° | 84° | 34" | 39" |
| Marshall, MN | 6° | 84° | 28" | 44" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Little Sioux averaged 1.1° warmer than the 1900s. The biggest change is in January (+2.4°).
A smaller shift than in 71% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Little Sioux compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Little Sioux’s place among Iowa’s.
Little Sioux weather by month
Highs, lows and precipitation from NOAA’s grid at Little Sioux’s center; snow, wet days and snow on the ground from Little Sioux 2 Nw, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 31° | 12° | 0.7" | 10.0" | 8 | 19 | 13° – 35° |
| February | 36° | 16° | 0.9" | 13.4" | 8 | 19 | 15° – 35° |
| March | 49° | 28° | 1.7" | 6.9" | 9 | 6 | 31° – 54° |
| April | 62° | 38° | 3.2" | 1.9" | 10 | 1 | 42° – 56° |
| May | 73° | 50° | 4.6" | 0.3" | 14 | 0 | 56° – 67° |
| June | 83° | 61° | 4.5" | 0.0" | 13 | 0 | 68° – 76° |
| July | 86° | 64° | 3.4" | 0.0" | 10 | 0 | 70° – 82° |
| August | 84° | 62° | 3.8" | 0.0" | 10 | 0 | 67° – 77° |
| September | 77° | 53° | 3.3" | 0.0" | 10 | 0 | 59° – 71° |
| October | 64° | 40° | 2.3" | 1.0" | 9 | 1 | 45° – 57° |
| November | 48° | 27° | 1.3" | 2.3" | 6 | 2 | 28° – 49° |
| December | 35° | 17° | 1.1" | 9.8" | 7 | 13 | 13° – 32° |
| Year | 61° | 39° | 30.8" | 45.6" | 114 | 61 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 31° to 54°. June is the most reliable, staying within 9°.
Where Little Sioux’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Little Sioux’s center.
- Snow: Little Sioux 2 Nw, IA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Little Sioux 2 Nw, IA, 1.7 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Little Sioux’s climate
What is the weather like in Little Sioux?
A typical July afternoon reaches 86°, a January night drops to 12°, and about 46 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; hotter July afternoons than 55% of U.S. towns.
How cold does it get in Little Sioux in winter?
January nights average 12°. About 165 nights a year reach 32° or below and 21 reach 0° or below. In the coldest January of the last 30 years the month averaged 13°.
How much snow does Little Sioux get?
About 46 inches in a normal winter at Little Sioux 2 Nw, IA, most of it in February, with snow on the ground about 61 days a year.
How hot does it get in Little Sioux?
July, with a typical high of 86° and a low of 64°. About 26 days a year reach 90° and 1 reach 100° (Little Sioux 2 Nw, IA).
When is the first and last frost in Little Sioux?
In half of years the last spring frost (32°) comes by May 1 and the first fall frost by October 3, about 155 frost-free days, at Little Sioux 2 Nw, IA.
What growing zone is Little Sioux in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Little Sioux?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Little Sioux getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 71% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Little Sioux.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.