Frost dates for ZIP 61360 (Seneca, IL)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Marseilles Lock, IL (8 miles away).
- Average last spring frostApr 2750% chance of a 32°F freeze after this date
- Average first fall frostOct 1750% chance of a 32°F freeze by this date
- Growing season (frost-free)171 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°F avg. coldest night
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This week in your yard
As of Oct 17, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
54°F 50–55°F
24-hour average · latest 54°F, as of Oct 17, 9:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shabbona 5 NNE (37 mi).
4-inch depth
55°F 55°F or warmer
24-hour average · latest 54°F, as of Oct 17, 9:00 PM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Shabbona 5 NNE (37 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 61360 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 55°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
Fertilizer window
Lawn region: North (cool-season). Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Oct 17: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Apr 12 |
| 50% (the "average" last frost) | Apr 27 |
| 10% (cautious: only 1 year in 10 freezes later) | May 13 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Oct 3 |
| 50% (the "average" first frost) | Oct 17 |
| 90% (late: most years have frozen by now) | Oct 29 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 7 | Oct 7 |
| 32°F (freeze) | Apr 27 | Oct 17 |
| 28°F (hard freeze) | Apr 15 | Oct 27 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 61360
Dates count from your average last spring frost (Apr 27) and first fall frost (Oct 17). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 2–16 | May 4–18 (transplant) | – |
| Pepper (sweet and hot) | Feb 16–Mar 2 | May 11–25 (transplant) | – |
| Eggplant | Feb 16–Mar 2 | May 11–25 (transplant) | – |
| Tomatillo | Mar 2–16 | May 4–18 (transplant) | – |
| Lettuce | Mar 2–16 | Apr 6–27 (transplant) Mar 30–May 11 (sow outdoors) | Aug 22–Sep 12 (transplant) Aug 8–Sep 5 (sowing) |
| Spinach | – | Mar 16–Apr 6 (sow outdoors) | Aug 22–Sep 12 (sowing) |
| Kale | Mar 2–16 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Jul 25–Aug 22 (transplant) Jul 11–Aug 8 (sowing) |
| Collards | Mar 2–16 | Mar 30–Apr 27 (transplant) Mar 30–Apr 27 (sow outdoors) | Jul 25–Aug 22 (transplant) Jul 11–Aug 8 (sowing) |
| Broccoli | Feb 16–Mar 2 | Mar 30–Apr 13 (transplant) | Jul 11–Aug 8 (transplant) |
| Cabbage | Feb 16–Mar 2 | Mar 30–Apr 13 (transplant) | Jul 11–Aug 8 (transplant) |
| Cauliflower | Feb 16–Mar 2 | Apr 13–27 (transplant) | Jul 11–Aug 8 (transplant) |
| Brussels sprouts | Feb 2–16 | Mar 30–Apr 13 (transplant) | Jun 27–Jul 18 (transplant) |
| Kohlrabi | Mar 2–16 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Aug 8–22 (sowing) |
| Bok choy / Asian greens | – | Mar 30–Apr 13 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Arugula | – | Mar 30–Apr 27 (sow outdoors) | Aug 22–Sep 19 (sowing) |
| Mustard greens | – | Mar 30–Apr 20 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Swiss chard | Mar 16–30 | Apr 13–May 4 (transplant) Apr 13–May 11 (sow outdoors) | Aug 8–22 (sowing) |
| Beet | – | Mar 30–Apr 27 (sow outdoors) | Aug 8–22 (sowing) |
| Carrot | – | Apr 6–May 4 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Radish | – | Mar 23–May 4 (sow outdoors) | Sep 5–19 (sowing) |
| Turnip | – | Mar 30–Apr 20 (sow outdoors) | Aug 8–22 (sowing) |
| Parsnip | – | Apr 6–27 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 2–30 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Onion (bulbing) | Feb 2–16 | Mar 16–30 (transplant) | – |
| Green onion / scallion | – | Mar 16–Apr 13 (sow outdoors) | Aug 8–22 (sowing) |
| Leek | Feb 2–16 | Mar 30–Apr 13 (transplant) | – |
| Garlic | – | – | Sep 5–Oct 3 (sowing) |
| Shallot | – | Mar 16–30 (transplant) | Sep 5–Oct 3 (sowing) |
| Potato | – | Mar 30–Apr 13 (transplant) | Jun 27–Jul 11 (transplant) |
| Sweet potato | – | May 18–Jun 1 (transplant) | – |
| Sweet corn | – | May 4–18 (sow outdoors) | – |
| Bean, bush (snap) | – | May 4–18 (sow outdoors) | – |
| Bean, pole | – | May 4–18 (sow outdoors) | – |
| Lima bean | – | May 11–25 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 18–Jun 8 (sow outdoors) | – |
| Cucumber | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Summer squash / zucchini | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Winter squash | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Pumpkin | – | May 4–18 (sow outdoors) | – |
| Watermelon | Mar 30–Apr 6 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 30–Apr 6 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Okra | Mar 16–30 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Celery | Feb 2–16 | May 4–11 (transplant) | – |
| Basil | Mar 16–30 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Cilantro | – | Apr 13–May 11 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Parsley | Feb 16–Mar 2 | Apr 13–27 (transplant) Apr 6–27 (sow outdoors) | – |
| Dill | – | Apr 27–May 11 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Sunflower | – | Apr 27–May 11 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 30–Apr 13 (transplant) | – |
| Rhubarb (crowns) | – | Mar 30–Apr 13 (transplant) | – |
| Strawberry (plants) | – | Mar 30–Apr 13 (transplant) | Aug 8–Sep 5 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Marseilles Lock, IL (NOAA GHCN-Daily ID USC00115372), elevation 490 ft, 8.0 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Morris 1 NW, IL | 9 mi | Apr 20 | Oct 23 |
| Ottawa 5SW, IL | 16 mi | Apr 20 | Oct 22 |
| Channahon Dresden Isl Dam, IL | 17 mi | Apr 16 | Oct 26 |
The average last-frost dates of these stations span 11 days, a rough guide to local variation. See data sources & methods.
Frost questions for 61360
When is the last frost in 61360?
The average (50% chance) last spring freeze of 32°F for ZIP 61360 is April 27. For a more cautious planting date, use May 13, when only 1 year in 10 still sees a later freeze.
When is the first frost in 61360?
The average first fall freeze is October 17. In 1 year in 10 it comes by October 3.
What hardiness zone is 61360?
ZIP 61360 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 61360 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
61341 Marseilles 60479 Verona 60450 Morris 60470 Ransom 60557 Wedron 60444 Mazon 60437 Kinsman 61325 Grand Ridge
Other ZIP codes in LaSalle County
60470 60518 60531 60537 60549 60551 60557 61301 61316 61321 61325 61332 61334 61341 61342 61348 61350 61354 61358 61364 61370 61371 61372 61373 All LaSalle County frost dates · Illinois frost dates
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