What to do in Sioux Falls now
Sioux Falls is in cool-season grass country. Dates are typical for this spot, worked out from 23 years of weather at Sioux Falls Foss Field; each status uses this year's soil estimates.
Cool-season: tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue
- Crabgrass pre-emergent Closed May 15 Typical: Apr 13 – May 32-inch soil held 55°F for a week from May 15, so crabgrass was sprouting. Next window: about Apr 13 – May 3, 2027.
- Seed or overseed Late · risky Typical: Sep 8 – Oct 16Soil fell below 55°F on Oct 22. Seed sown now germinates slowly and may not survive winter. The hard stop, 4-inch soil under 50°F, typically comes around Oct 25.
- Late-fall feeding Final feeding due now Typical: Oct 25 – Nov 16Not too late. Feed on your normal fall schedule; the last feeding of the year goes down when 4-inch soil falls to about 50°F (typically Oct 25) and before it reaches 40°F (typically Nov 16).
Warm-season: bermudagrass, zoysia, St. Augustine, centipede, bahia
- Crabgrass pre-emergent Closed May 15 Typical: Apr 13 – May 32-inch soil held 55°F for a week from May 15, so crabgrass was sprouting. Next window: about Apr 13 – May 3, 2027.
- Seed or sod Wait for late spring Typical: May 26 – Sep 8Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about May 26.
- Fall pre-emergent (Poa annua) Germinating since Sep 16 Typical: By Sep 74-inch soil fell below 70°F on Sep 16, when annual bluegrass begins to sprout. A pre-emergent now only stops later flushes; plan to apply by about Sep 7 next year.
- Dormancy and last feeding Dormant since about Oct 22 Typical: Around Oct 164-inch soil has stayed under 55°F since Oct 22, so warm-season grass is going brown. It is too late to fertilize; feed again after spring green-up, once soil holds 65°F (typically May 26).
The last 60 days and the week ahead
Sioux Falls soil is 11° warmer than normal for Nov 3, warmer than on 97% of those dates since 2005, and 10° warmer than a year ago.
The green line is our estimate of the daily average soil temperature 2 inches down, driven by temperatures at Sioux Falls Foss Field, 4.5 km from the city center. The dashed part runs the National Weather Service forecast through the same model. Hover or tap for any day.
2-inch soil, estimated From the NWS forecast Normal Normal range (8 years in 10)
Show the numbers
| Date | 2-inch soil | 4-inch soil | Air high / low | Normal (2 in) |
|---|---|---|---|---|
| Oct 21 | 54° | 56° | 73° / 44° | 49° |
| Oct 22 | 56° | 57° | 78° / 42° | 49° |
| Oct 23 | 59° | 60° | 75° / 59° | 48° |
| Oct 24 | 58° | 59° | 66° / 45° | 48° |
| Oct 25 | 54° | 56° | 49° / 41° | 47° |
| Oct 26 | 51° | 53° | 43° / 41° | 46° |
| Oct 27 | 50° | 52° | 53° / 42° | 46° |
| Oct 28 | 50° | 52° | 61° / 40° | 45° |
| Oct 29 | 49° | 51° | 62° / 32° | 45° |
| Oct 30 | 48° | 50° | 55° / 37° | 44° |
| Oct 31 | 51° | 52° | 65° / 52° | 44° |
| Nov 1 | 53° | 54° | 60° / 53° | 44° |
| Nov 2 | 56° | 56° | 69° / 56° | 44° |
| Nov 3 | 54° | 55° | 56° / 45° | 43° |
| Nov 4 (forecast) | 50° | 52° | 45° / 38° | 43° |
| Nov 5 (forecast) | 47° | 49° | 46° / 32° | 43° |
| Nov 6 (forecast) | 44° | 47° | 45° / 30° | 43° |
| Nov 7 (forecast) | 44° | 46° | 52° / 35° | 43° |
| Nov 8 (forecast) | 44° | 47° | 55° / 38° | 43° |
| Nov 9 (forecast) | 46° | 47° | 60° / 38° | 42° |
| Nov 10 (forecast) | 47° | 48° | 57° / 41° | 42° |
Which grass grows in Sioux Falls
Sioux Falls winters are cold enough (January averages 18°F) that cool-season grasses, mostly Kentucky bluegrass, tall fescue and perennial ryegrass, make up most lawns. They grow in spring and fall and slow down in summer heat.
Sioux Falls soil through the year
Weekly 2-inch estimates for 2026 so far against 2025 and the normal for each week. The red lines mark 50°F, when crabgrass pre-emergent should be down, and 65°F, when warm-season seed sprouts well.
2026 2025 Normal (2005–2025) 8 years in 10
Normal by month
| Month | 2 in | 4 in | Air |
|---|---|---|---|
| Jan | 31° | 33° | 18° |
| Feb | 32° | 34° | 23° |
| Mar | 38° | 39° | 35° |
| Apr | 47° | 48° | 47° |
| May | 59° | 60° | 59° |
| Jun | 71° | 72° | 70° |
| Jul | 76° | 77° | 74° |
| Aug | 73° | 75° | 72° |
| Sep | 66° | 68° | 64° |
| Oct | 52° | 54° | 50° |
| Nov | 39° | 41° | 35° |
| Dec | 32° | 34° | 23° |
Soil: average of our daily estimates, 2005–2025. Air: NOAA 1991–2020 normals for the station.
Typical lawn dates in Sioux Falls
Each date is when the soil estimate (or the air, for freezes) crossed the threshold, year by year since 2005. “Early” and “late” are the 10th and 90th percentile years, so 8 years in 10 fall between them.
| Event | Typical | 2026 |
|---|---|---|
| Last spring freeze (32°F) | Apr 30 | May 20 |
| Crabgrass model: 250 growing degree days | Apr 3 | Mar 19 |
| Pre-emergent window opens (2-inch soil 50°F) | Apr 13 | Apr 15 |
| Crabgrass begins to sprout (2-inch soil 55°F) | May 3 | May 15 |
| Cool-season lawns start growing (4-inch soil 55°F) | May 2 | Apr 26 |
| Warm-season seeding opens (4-inch soil 65°F) | May 26 | May 29 |
| Cool-season seeding opens (4-inch soil under 70°F) | Sep 8 | Sep 18 |
| Cool-season seeding ends (4-inch soil under 55°F) | Oct 16 | Oct 22 |
| Warm-season grass goes dormant (4-inch under 55°F) | Oct 16 | Oct 22 |
| First fall freeze (32°F) | Oct 8 | Oct 17 |
| Roots stop feeding (4-inch soil under 40°F) | Nov 16 | not yet |
Checked against a real sensor
Measured nearby: 51°F at 2 inches on Nov 3, at the USDA SCAN site “Eros Data Center”, 15 miles away.
Our estimate for Sioux Falls on Nov 3 is 54°F; the sensor read 53°F at 4 inches against our 55°F. Sensor sites sit in open, unwatered ground outside town, so they often run a few degrees apart from city lawns; use them as a check on the trend.
There is no soil sensor in most cities, so we estimate it. Shallow soil follows air temperature with a lag of a few days, and runs a little warmer than the air in fall. We fitted that relationship to 190 USDA soil-sensor stations; on years held out of the fit, the estimate was off by 3.3°F on an average day, and it put the spring 55°F date within a median of 3 days. Read the methodology.
Weather: RCC ACIS station KFSD (SIOUX FALLS FOSS FIELD), daily data since 1893. Forecast: National Weather Service, FSD office, issued Nov 4, 2026, 5:43 AM EST. Last observed day: Nov 3, 2026.
Sioux Falls questions
What is the soil temperature in Sioux Falls today? Our estimate for Nov 3 is 54°F at 2 inches and 55°F at 4 inches, as a daily average. Early-morning soil runs a few degrees cooler than that, and afternoon soil warmer.
When should I put down crabgrass pre-emergent in Sioux Falls? Apply when 2-inch soil holds about 50°F and before it holds 55°F. That has typically been Apr 13 to May 3 in Sioux Falls. For 2026 the window closed on May 15.
Is it too late to overseed in Sioux Falls? Late · risky. Soil fell below 55°F on Oct 22. Seed sown now germinates slowly and may not survive winter. The hard stop, 4-inch soil under 50°F, typically comes around Oct 25.
Is it too late to fertilize in Sioux Falls? Final feeding due now. Not too late. Feed on your normal fall schedule; the last feeding of the year goes down when 4-inch soil falls to about 50°F (typically Oct 25) and before it reaches 40°F (typically Nov 16).
When is the last frost in Sioux Falls? The last 32°F night of spring has typically come around Apr 30, and as late as May 15 in 1 year in 10. The first fall freeze typically arrives around Oct 8.
Why 2 inches and 4 inches? Crabgrass and most weed seeds sprout in the top inch or two, so pre-emergent timing follows 2-inch soil. Grass seed and roots respond to the slightly steadier soil at about 4 inches.
How accurate is this? It is a model, not a probe in your yard. Expect about 3–4°F of difference on a given day; shade, slope, mulch and irrigation all move real soil. The dates and trends are more reliable than any single day.