WhenToApplyPreEmergent.com

National fall field report October 16, 2026

The largest current group is 50–65°f: 46% of covered U.S. ZCTAs.

The latest verified release places 15,493 of 33,565 covered ZCTAs in the modeled soil 50–65°f band in the soil-temperature distribution. The band is keyed to modeled 2–4 inch soil temperature, not the spring crabgrass GDD model. The report rebuilds daily from the same citable GDD release used by the public data product.

Check your ZIP's overseeding status See all 50 states

01

The national pulse

The current distribution across four modeled fall-timing bands

Above 72°F modeled soil
22.9%

Above 72°F

7,677 ZCTAs

65–72°F modeled soil
26.1%

65–72°F

8,769 ZCTAs

50–65°F modeled soil
46.2%

50–65°F

15,493 ZCTAs

Below 50°F modeled soil
4.8%

Below 50°F

1,626 ZCTAs

National median soil 64.8°F

The midpoint covered ZCTA is soil 50–65°f in the soil-temperature distribution.

Geographic spread 52.8°F–75.9°F

The 10th–90th percentile modeled soil-temperature range across covered ZCTAs.

Season warmth (context) 3,820.2 GDD50

National median cumulative base-50 GDD from Jan. 1 in the same verified public release.

02

Reusable national image

State medians show how soil temperatures differ across the country

Map of the United States colored by each state's current median modeled soil-temperature band.
State color is based on the median modeled soil temperature among covered ZCTAs, while the all-state table preserves each state's full distribution. Medians can hide local elevation, coastal, lake, urban, and station-to-station variation. Archived download images may retain earlier seeding labels; those labels are not current planting advice. Use the ZIP tool for regional calendars.
PNG 1200 × 630 share image SVG scalable publisher graphic CSV accessible 50-state dataset

03

Twelve states to watch

The coolest state medians

01

Below 50°F

Alaska

Median 38.5°F modeled soil; 0% approaching, 0.4% open, and 29% cooling across 245 covered ZCTAs.

Open Alaska's overseeding tool
02

Below 50°F

Montana

Median 48.3°F modeled soil; 0% approaching, 37.4% open, and 98.4% cooling across 369 covered ZCTAs.

Open Montana's overseeding tool
03

Below 50°F

Vermont

Median 49.4°F modeled soil; 0% approaching, 36.6% open, and 100% cooling across 265 covered ZCTAs.

Open Vermont's overseeding tool
04

50–65°F

Maine

Median 50.4°F modeled soil; 0% approaching, 56.7% open, and 100% cooling across 427 covered ZCTAs.

Open Maine's overseeding tool
08

50–65°F

Idaho

Median 53.4°F modeled soil; 6.1% approaching, 65% open, and 88.9% cooling across 280 covered ZCTAs.

Open Idaho's overseeding tool
09

50–65°F

New York

Median 54.2°F modeled soil; 0% approaching, 93.8% open, and 91.1% cooling across 1,826 covered ZCTAs.

Open New York's overseeding tool
10

50–65°F

Oregon

Median 54.6°F modeled soil; 0% approaching, 82.9% open, and 99.8% cooling across 428 covered ZCTAs.

Open Oregon's overseeding tool
12

50–65°F

Wyoming

Median 55.8°F modeled soil; 6.3% approaching, 69.3% open, and 69.9% cooling across 176 covered ZCTAs.

Open Wyoming's overseeding tool

Read this before seeding or treating

A modeled temperature is not a prescription

This report summarizes modeled soil-temperature bands. These bands do not determine when to seed. The ZIP overseeding tool uses reviewed regional calendars and states their grass type, purpose and coverage limits.

Modeled soil temperature is an estimate with roughly ±5°F expected error versus an in-ground thermometer, especially under snow, shade, unusual moisture, or local terrain. Before using any pesticide, read and follow the current label on your container; before buying seed, confirm the blend and rate your region supports. Product registrations and state restrictions can change.

EPA: how to read legally enforceable pesticide labels

04

Fall pre-emergent is a different model

Not the spring crabgrass GDD window

Spring model

Crabgrass pre-emergents key to soil warming

This site's spring pre-emergent tool uses base-50 GDD accumulated from January 1 to time crabgrass and summer-annual products as soils warm. Nothing in this fall report uses those thresholds for fall products.

Fall model

Winter-annual pre-emergents key to soil cooling

Poa annua and other winter annuals germinate as soils cool. Extension guidance keys fall pre-emergent applications to modeled soil temperature dropping below about 70°F — the same signal this report publishes, not a GDD number.

Watch signal from this release

70.7% of covered ZCTAs currently sit at or below 70°F modeled soil. None should be treated yet — the signal is a prep cue for the northern tier and mountain states as soil temperatures keep falling, and it never overrides a product label or local Extension guidance.

Pre-emergents also block grass seed, so an overseeding plan changes what you can apply and when. Never apply a fall pre-emergent to an area you are seeding in the same season unless the label allows it.

05

All-state summary

Every state, the same verified public release

Status is assigned from each state's median ZCTA modeled soil temperature. The four count columns show the underlying within-state distribution so a median does not masquerade as a uniform state. GDD50 is season-warmth context from the same public release, not a fall application threshold.

Modeled fall lawn-timing status by state, generated October 16, 2026
State Median soil 10th–90th pct. Median GDD50 Modeled status Too warm Approaching Open Closing Cooling Available ZCTAs
Alabama AL 70.7°F 68°F–73.5°F 5,902.6 65–72°F 154 500 2 0 99.1% 656
Alaska AK 38.5°F 32°F–44.3°F 450.3 Below 50°F 0 0 1 244 29% 245
Arizona AZ 79.2°F 59.3°F–86°F 7,633.3 Above 72°F 267 49 99 1 44.2% 416
Arkansas AR 73.2°F 70.1°F–75.5°F 5,811.4 Above 72°F 484 130 0 0 28.2% 614
California CA 71.3°F 61.2°F–77.4°F 4,907.2 65–72°F 832 618 327 26 91% 1,803
Colorado CO 64.3°F 47.9°F–69.3°F 3,350 50–65°F 0 251 210 67 22.7% 528
Connecticut CT 56.6°F 52.3°F–58°F 2,961.9 50–65°F 0 0 288 0 100% 288
Delaware DE 63.3°F 62.4°F–64.2°F 4,163 50–65°F 0 0 68 0 100% 68
Florida FL 80.2°F 75.9°F–84.1°F 7,454 Above 72°F 1,003 10 0 0 67.2% 1,013
Georgia GA 70.3°F 66.3°F–74.9°F 5,747.3 65–72°F 252 486 13 0 99.5% 751
Hawaii HI 78°F 59.3°F–80.3°F 7,331.1 Above 72°F 83 1 11 2 77.3% 97
Idaho ID 53.4°F 44.5°F–61.2°F 2,369.2 50–65°F 0 17 182 81 88.9% 280
Illinois IL 67.9°F 64.8°F–69.9°F 3,817.5 65–72°F 5 1,230 161 0 9.2% 1,396
Indiana IN 63.9°F 61.4°F–66.8°F 3,732.5 50–65°F 0 232 575 0 19% 807
Iowa IA 68.5°F 66.1°F–70.5°F 3,459.1 65–72°F 12 918 40 0 1.6% 970
Kansas KS 72.8°F 70.7°F–74.8°F 4,731.3 Above 72°F 516 188 0 0 4.3% 704
Kentucky KY 64°F 62.1°F–68.3°F 4,337.9 50–65°F 16 179 584 0 85.1% 779
Louisiana LA 76.3°F 74.5°F–77.4°F 6,743.5 Above 72°F 539 0 0 0 98.3% 539
Maine ME 50.4°F 45.2°F–53.6°F 2,163.4 50–65°F 0 0 242 185 100% 427
Maryland MD 62.9°F 59.4°F–65.5°F 4,135.4 50–65°F 0 79 398 0 100% 477
Massachusetts MA 54.8°F 52.3°F–58.6°F 2,687.6 50–65°F 0 0 521 18 100% 539
Michigan MI 60.4°F 55.9°F–62.6°F 2,765.9 50–65°F 0 0 992 0 12.2% 992
Minnesota MN 63.1°F 54.9°F–67.6°F 2,809.1 50–65°F 0 321 550 9 6.7% 880
Mississippi MS 74.1°F 71.2°F–76°F 6,254.4 Above 72°F 324 103 0 0 98.4% 427
Missouri MO 71.3°F 68.2°F–74.6°F 4,682.9 65–72°F 402 633 0 0 11% 1,035
Montana MT 48.3°F 39.2°F–54.7°F 2,081.7 Below 50°F 0 0 138 231 98.4% 369
Nebraska NE 69.9°F 64.9°F–72.4°F 3,783.3 65–72°F 98 425 63 0 1.9% 586
Nevada NV 64.9°F 48.2°F–77.2°F 3,855.1 50–65°F 73 16 69 22 88.9% 180
New Hampshire NH 51.4°F 48.5°F–53.8°F 2,397.6 50–65°F 0 0 182 64 100% 246
New Jersey NJ 60.5°F 57.7°F–62.3°F 3,748.2 50–65°F 0 0 598 0 100% 598
New Mexico NM 61.2°F 50.8°F–70.2°F 3,475.2 50–65°F 7 135 205 26 5.6% 373
New York NY 54.2°F 51°F–60.8°F 2,679.8 50–65°F 0 0 1,712 114 91.1% 1,826
North Carolina NC 68°F 62.4°F–70.7°F 4,955.8 65–72°F 25 627 201 0 69.6% 853
North Dakota ND 53.2°F 49.5°F–58°F 2,488.8 50–65°F 0 0 318 71 69.9% 389
Ohio OH 60.7°F 58.9°F–63.3°F 3,384.2 50–65°F 0 0 1,233 0 23.2% 1,233
Oklahoma OK 74.8°F 73°F–76.2°F 6,051.7 Above 72°F 601 43 0 0 10.7% 644
Oregon OR 54.6°F 48.4°F–57.9°F 2,313.8 50–65°F 0 0 355 73 99.8% 428
Pennsylvania PA 57.4°F 53.8°F–60.8°F 3,160.2 50–65°F 0 0 1,833 0 87.8% 1,833
Rhode Island RI 58.3°F 52°F–58.3°F 3,150.4 50–65°F 0 0 81 0 100% 81
South Carolina SC 69.1°F 66.1°F–73.1°F 5,439.6 65–72°F 60 355 9 0 89.4% 424
South Dakota SD 61°F 55.8°F–65.9°F 3,113.3 50–65°F 0 67 306 2 44.8% 375
Tennessee TN 67.9°F 64.1°F–71.2°F 5,076 65–72°F 55 471 112 0 91.1% 638
Texas TX 77.1°F 73.6°F–80.6°F 7,010.2 Above 72°F 1,866 122 1 0 57.1% 1,989
Utah UT 59°F 47.7°F–65.9°F 2,828.9 50–65°F 3 34 213 49 92.6% 299
Vermont VT 49.4°F 45.7°F–51.5°F 2,039 Below 50°F 0 0 97 168 100% 265
Virginia VA 63.4°F 59.1°F–68.3°F 4,301.8 50–65°F 0 314 589 0 92.9% 903
Washington WA 52.9°F 46.3°F–56.5°F 2,091.1 50–65°F 0 0 475 130 98.2% 605
West Virginia WV 60.2°F 56.4°F–64.6°F 3,658.2 50–65°F 0 56 682 0 88.2% 738
Wisconsin WI 63.5°F 58.1°F–65.8°F 2,738.3 50–65°F 0 148 635 0 7% 783
Wyoming WY 55.8°F 46°F–64.3°F 2,459.1 50–65°F 0 11 122 43 69.9% 176

Need the values in a newsroom or analysis workflow? Download the CSV with soil temperatures, GDD context, aeration and pre-emergent shares, dates, and state-tool URLs.

06

Method & uncertainty

How the report was generated

01

Start with the verified public GDD release

Every GDD value derives from public release 2026-10-16, identified by its SHA-256 checksum. It contains 33,642 nationwide ZCTA rows; this 50-state report includes 33,565 fresh values.

02

Model soil temperature from air temperature

Each ZCTA's 2–4 inch soil temperature is estimated from its station's daily NOAA Tmax/Tmin with an exponentially weighted lag model (alpha 0.25/day, 7-data-day trend). It is a modeled estimate, not an in-ground sensor reading, with roughly ±5°F expected error.

03

Use a freshness-aware station chain

Each ZCTA can consider up to 8 nearby candidates. The pipeline uses the nearest station with sufficiently fresh Tmax/Tmin data and falls back when a closer station is stale or incomplete — the same chain behind the public GDD release.

04

Separate temperature bands from planting guidance

The temperature distribution retains its existing bands for comparison over time: above 72°F, above 65°F through 72°F, 50–65°F , and below 50°F. These are not germination windows. The ZIP overseeding tool provides separate regional calendar guidance. Archived files retain their original field names and labels. Aeration shares use the aeration tool's fall window (48–65°F). Fall pre-emergent readiness is a separate 70°F-and-falling watch signal — never the spring GDD model.

What the model cannot see

Elevation, coast and lake effects, urban heat, shade, snow cover, irrigation, soil moisture and texture, and turf condition all shift real soil temperatures. Recent GHCN-Daily records may lag and can later be replaced by archive-quality values. A station-based estimate is a planning proxy, not a measurement of an individual lawn.

Read the full site methodology

07

Primary sources

Research and first-party guidance behind the framing

  1. Penn State Extension: overseeding turfgrass Fall establishment windows and seedbed preparation.
  2. University of Minnesota Extension: overseeding lawns Soil-temperature-gated late-summer/fall seeding guidance.
  3. Michigan State Extension: lawn management in early fall Fall seeding, aeration, and renovation sequence.
  4. Cornell Turfgrass Program: lawn renovation When core aeration and overseeding fit the cool-season cycle.
  5. University of Minnesota Extension: poa annua management Fall pre-emergent timing keyed to soil temperature cooling, not GDD.
  6. UW–Madison Turf: poa annua Winter-annual lifecycle and fall prevention windows.
  7. NOAA NCEI GHCN-Daily Daily station Tmax/Tmin and data-quality context.
  8. U.S. EPA pesticide labels Legally enforceable directions and restrictions.

From national signal to local check

Move from the national signal to your ZIP.

This stable report URL follows the latest verified daily release. The overseeding and aeration tools show the current modeled soil temperature, observation date, and station distance for a specific location.

Check your ZIP's fall overseeding status
Cite this data

Referencing this page in an article, newsletter, or forum answer? Copy the suggested citation below — it keeps the attribution, link, and model caveat accurate.

Fall lawn-timing field report (release 2026-10-16) — WhenToApplyPreEmergent.com (Offshoot Labs), https://whentoapplypreemergent.com/reports/fall-lawn-timing/2026-10-16/. Data through October 9, 2026 to October 13, 2026. Soil temperatures are modeled estimates (about ±5°F), not sensor readings.