Sioux Falls, SD Frost Dates: Last Spring and First Fall Frost

In a typical year the final freeze of spring reaches Sioux Falls around May 1, and the first freeze of autumn returns around October 6. NOAA's normals call the frost-free stretch between them 157 days long.

Even odds are a coin toss, so plan around the safer edges: one spring in ten still has a freeze on or after May 14, and one fall in ten has its first freeze by September 23. The median season across the 100 cities on these pages is 229 days; Sioux Falls comes up 72 days short of it, 97th on the list.

These dates come from the NOAA weather station Sioux Falls (ID USW00014944), 3.3 miles north of the Census Bureau's internal point for Sioux Falls, at about 1,450 feet above sea level.

Last spring frost in Sioux Falls

Read the table from the top: a freeze on or after May 14 is a one-in-ten spring, after May 1 is a coin toss, and after April 18 is the usual case.

The early and late dates sit just 26 days apart, narrower than for most cities on these pages. Spring in Sioux Falls rarely surprises by much.

First fall frost in Sioux Falls

In Sioux Falls the first freeze has arrived by September 23 in one fall out of ten, by October 6 in five, and by October 20 in nine.

Fall frost keeps to a tight calendar in Sioux Falls: 27 days from the 10% date to the 90% date, less than in most of the 100 cities here.

Sioux Falls's frost-free season

A season this much shorter than the middle of the pack leaves little slack for slow crops, as the planting dates below show. There is little difference between a typical season (157 days) and a short one (138 days) in Sioux Falls: 19 days, less than in most of the cities covered here.

The season lengths come from NOAA's simulated years, not from subtracting one typical date from the other, so the two will not match to the day. A night at or below 32°F happens in 100% of years at this station, so frost is a yearly event here.

Hard freeze dates for Sioux Falls

Between a light frost and a hard freeze there is little room in Sioux Falls: the typical 28°F dates are October 17 and April 22, just 11 days and 9 days from the 32°F dates. At the edges, a 28°F night on or after May 5 happens one spring in ten and one by October 1 one fall in ten; the nine-in-ten dates are April 8 and October 30.

Planting dates for Sioux Falls, counted from the frost dates

University of New Hampshire Extension sorts vegetables by how they cope with cold. Cool-season crops go out before the last frost: counting from May 1, cabbage transplants go in on April 3 and lettuce from April 3 to April 10. Tender crops wait until it has passed, with peppers going out on May 15 and beans sown on or after May 1. Peas are the exception to the count: University of New Hampshire Extension says to plant them as soon as the soil thaws, whatever the frost date.

Counting from the late date, May 14, instead of the typical one delays every after-frost crop by 13 days. That is the price of a one-in-ten spring that most years will not need.

Fall crops are counted back from the first frost, using NC State Extension's days to harvest plus University of Georgia Extension's harvest allowance of 18 days. In Sioux Falls only 20 of the 34 crops in the fall planner have a last planting day in July or later, and the other 14 would have to go in before then, in spring or early summer. The slowest crop that still fits is cauliflower, at 83 days, and it has to be planted by July 2 to beat the early date.

Worked example: setting out tomatoes in Sioux Falls

Suppose you want tomatoes in Sioux Falls. University of New Hampshire Extension says to set transplants out one to two weeks after the last frost. Counting from the typical date, May 1, the window runs from May 8 to May 15. Counting from the late date, May 14, it moves to May 21 through May 28, which is 13 days later.

Indoors, tomato seeds go in six to eight weeks ahead of set-out; from the first day of the late window that is March 26 to April 9.

That leaves 118 days against 75 to 85 days for the plants to reach harvest, so even the late schedule fits in an early-frost year with 33 days to spare.

Where Sioux Falls's numbers are measured

The station is 3.3 miles north of the Census Bureau's internal point for Sioux Falls, near enough to be the city's reference record, though not in the same yard.

At about 1,450 feet, it ranks above 81 and below 18 of the 100 stations used for these pages. Its completeness flag is S, which NOAA uses for a standard record.

The Census Gazetteer gives no elevation for Sioux Falls itself, so this page cannot tell you whether your garden sits above or below the station. If it is noticeably higher or lower, compare the stations the frost dates tool lists nearby and lean toward the colder reading.

How Sioux Falls's frost dates compare

Sioux Falls is far from its neighbors on these pages: the closest, Omaha, NE, is 161 miles away, so expect its dates to belong to a different climate.

• Omaha, NE, 161 miles to the south: last frost April 16, first frost October 18, 183 days frost-free; spring frost ends 15 days sooner than in Sioux Falls, and the frost-free season is 26 days longer than Sioux Falls's.
• Lincoln, NE (189 miles, south): the last frost is 7 days earlier than in Sioux Falls, and the frost-free season is 14 days longer than Sioux Falls's. Its typical dates are April 24 and October 13, with 171 days frost-free.
• Minneapolis, MN (198 miles, north-east): its last frost comes 8 days before Sioux Falls's, and the season runs 18 days longer. Its typical dates are April 23 and October 16, with 175 days frost-free.

Put the frost dates to work

Open the frost dates tool with this station already chosen to see the whole ladder of probability dates, or try the nearby stations in the same list. The spring planting planner and the fall planting planner turn the same dates into a full crop list, and the hardiness zone lookup tells you which perennials will survive the winter.

All the cities on these pages are listed by state on the city frost dates index.

Where these numbers come from

NOAA's U.S. Climate Normals for 1991–2020 (doi:10.25921/4ek7-fk11) supply every frost date here, unchanged from the station's record, and NOAA's documentation defines the probabilities. The Census Bureau's 2024 Gazetteer places Sioux Falls on the map, and its Vintage 2024 estimates, 209,289 people here, decide which cities get a page.

The planting dates apply the count rules in University of New Hampshire Extension, NC State Extension and University of Georgia Extension to this station's dates, with nothing added. The methodology page explains how each figure is checked.

NOAA's dates say how often frost has come, not when it will. Check the forecast before planting and keep a cover on hand.