Arthur, IL frost dates
Last spring frostApr 15median date
First fall frostOct 20median date
Growing season188 daysfrost-free
Hardiness zone6aZone 6a
How Arthur compares
- In 8 years out of 10, the last spring frost in Arthur falls between April 3 and May 1, a 28-day window. The first fall frost falls between October 7 and November 1.
- The median last frost is 2 days earlier than the Illinois median of Apr 17.
- Its 188-day growing season is longer than 51% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 14 days earlier than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 117 nights a year at or below 32°F.
- Compared with Decatur, IL, 46 km away, the last frost here is 1 day later than there and the growing season is 5 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 3 |
| 50% (median) | April 15 |
| 10% (safe for tender plants) | May 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 7 |
| 50% (median) | October 20 |
| 90% (late) | November 1 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Arthur, IL
Arthur, IL frost dates — last frost Apr 15, first frost Oct 20, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 21 to Feb 4Transplant outside: Mar 18 to Apr 1
Start indoors: Feb 4 to Feb 18Transplant outside: Apr 29 to May 13
Start indoors: Feb 4 to Feb 18Transplant outside: Apr 29 to May 13
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 22 to May 6
Start indoors: Feb 18 to Mar 4Transplant outside: Mar 25 to Apr 8Sow outdoors: Mar 18 to Apr 22Plant for fall: Aug 25 to Sep 22
Start indoors: Feb 18 to Mar 4Transplant outside: Mar 18 to Apr 1Sow outdoors: Mar 18 to Apr 1Plant for fall: Aug 11 to Sep 1
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 1 to Apr 15Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 18 to Mar 4Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 1 to Apr 15Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 4 to Mar 18Transplant outside: May 6 to May 20Sow outdoors: May 6 to May 20
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 22 to May 6
Sow outdoors: Mar 4 to Mar 25Plant for fall: Jul 28 to Aug 18
Sow outdoors: Mar 4 to Mar 25Plant for fall: Aug 25 to Sep 15
Sow outdoors: Mar 11 to Apr 22Plant for fall: Sep 8 to Sep 29
Start indoors: Mar 18 to Mar 25Transplant outside: Apr 29 to May 6Sow outdoors: Apr 22 to May 6Plant for fall: Aug 4 to Aug 18
Start indoors: Mar 18 to Mar 25Sow outdoors: Apr 22 to May 6Plant for fall: Aug 11 to Aug 25
Start indoors: Mar 18 to Mar 25Sow outdoors: Apr 22 to May 6
Start indoors: Mar 18 to Mar 25Transplant outside: Apr 29 to May 13
Sow outdoors: Mar 25 to Apr 22Plant for fall: Jul 28 to Aug 11
Sow outdoors: Mar 25 to Apr 22Plant for fall: Aug 11 to Aug 25
Sow outdoors: Mar 25 to Apr 15
Sow outdoors: Apr 1 to Apr 29Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 1 to Apr 22Plant for fall: Aug 25 to Sep 15
Sow outdoors: Apr 22 to May 13Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 22 to May 6
Transplant outside: Apr 29 to May 20
Plant for fall: Oct 6 to Nov 10
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Arthur, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 21 – Feb 4 | Mar 18 – Apr 1 | — | — |
| Peppers | Feb 4 – Feb 18 | Apr 29 – May 13 | — | — |
| Eggplant | Feb 4 – Feb 18 | Apr 29 – May 13 | — | — |
| Tomatoes | Feb 18 – Mar 4 | Apr 22 – May 6 | — | — |
| Lettuce | Feb 18 – Mar 4 | Mar 25 – Apr 8 | Mar 18 – Apr 22 | Aug 25 – Sep 22 |
| Kale | Feb 18 – Mar 4 | Mar 18 – Apr 1 | Mar 18 – Apr 1 | Aug 11 – Sep 1 |
| Broccoli | Feb 18 – Mar 4 | Apr 1 – Apr 15 | — | Jul 14 – Aug 4 |
| Cabbage | Feb 18 – Mar 4 | Mar 25 – Apr 8 | — | Jul 14 – Aug 4 |
| Cauliflower | Feb 18 – Mar 4 | Apr 1 – Apr 15 | — | Jul 14 – Aug 4 |
| Okra | Mar 4 – Mar 18 | May 6 – May 20 | May 6 – May 20 | — |
| Basil | Mar 4 – Mar 18 | Apr 22 – May 6 | — | — |
| Peas | — | — | Mar 4 – Mar 25 | Jul 28 – Aug 18 |
| Spinach | — | — | Mar 4 – Mar 25 | Aug 25 – Sep 15 |
| Radishes | — | — | Mar 11 – Apr 22 | Sep 8 – Sep 29 |
| Cucumbers | Mar 18 – Mar 25 | Apr 29 – May 6 | Apr 22 – May 6 | Aug 4 – Aug 18 |
| Zucchini & Summer Squash | Mar 18 – Mar 25 | — | Apr 22 – May 6 | Aug 11 – Aug 25 |
| Winter Squash & Pumpkins | Mar 18 – Mar 25 | — | Apr 22 – May 6 | — |
| Melons & Watermelon | Mar 18 – Mar 25 | Apr 29 – May 13 | — | — |
| Carrots | — | — | Mar 25 – Apr 22 | Jul 28 – Aug 11 |
| Beets | — | — | Mar 25 – Apr 22 | Aug 11 – Aug 25 |
| Potatoes | — | — | Mar 25 – Apr 15 | — |
| Swiss Chard | — | — | Apr 1 – Apr 29 | Aug 11 – Aug 25 |
| Cilantro | — | — | Apr 1 – Apr 22 | Aug 25 – Sep 15 |
| Green Beans | — | — | Apr 22 – May 13 | Aug 4 – Aug 18 |
| Sweet Corn | — | — | Apr 22 – May 6 | — |
| Sweet Potatoes | — | Apr 29 – May 20 | — | — |
| Garlic | — | — | — | Oct 6 – Nov 10 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Tuscola, IL weather station, 17 km away (elevation 650 ft (198 m)).
Frost dates near Arthur
- Atwood Apr 15 · Oct 20
- Arcola Apr 15 · Oct 20
- Hammond Apr 15 · Oct 20
- Lovington Apr 15 · Oct 22
- Humboldt Apr 15 · Oct 24
- Sullivan Apr 15 · Oct 22
- Tuscola Apr 15 · Oct 20
- La Place Apr 16 · Oct 22
- Bement Apr 23 · Oct 13
- Gays Apr 16 · Oct 22
Frequently asked questions
When is the last frost in Arthur, IL?
The median last spring frost in Arthur, IL is April 15. There is still about a 10% chance of frost after May 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Arthur, IL?
The median first fall frost is October 20, with about a 10% chance of frost before October 7.
How long is the growing season in Arthur, IL?
About 188 days between the median last spring frost and first fall frost.
What planting zone is Arthur, IL?
Arthur, IL is in USDA hardiness zone 6a.