Naperville, Illinois planting calendar and frost dates
Naperville is in USDA hardiness zone 5b. The last spring frost typically comes around April 19 and the first fall frost around October 23, giving about 185 frost-free days a year.
- Typical last frost
- April 19
- Typical first frost
- October 23
- Frost-free season
- 185 days
Frost dates in Naperville
Last spring frost
- April 5Risky: frost later than this in 9 years out of 10
- April 19Typical: a later frost in half of years
- May 4Safe: a later frost only 1 year in 10
First fall frost
- October 9Risky: frost earlier than this 1 year in 10
- October 23Typical: an earlier frost in half of years
- November 3Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 185 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around April 8 and returns around November 2.
NOAA U.S. Climate Normals 1991-2020 for Aurora, 1.5 miles NNE of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers. Naperville shares this station with Aurora, so the two cities have the same frost dates and planting calendar.
What to plant each month in Naperville
January
Start indoors: collard greens, leeks, onions, petunias, ranunculus
February
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, ginger, kale, leeks, lettuce, marigolds, onions, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons
March
Start indoors: basil, black-eyed susans, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, lettuce, marigolds, nasturtiums, peppers, ranunculus, sage, snapdragons, spinach, swiss chard, tomatoes
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, dahlias, dill, figs, garden mums, ginger, gladioli, grapes, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, perennial ryegrass, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, turnips
May
Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, ginger, grapes, green beans, green onions, kentucky bluegrass, lavenders, lilies, marigolds, mints, nasturtiums, okra, oregano, parsley, peanuts, peppers, perennial ryegrass, petunias, pumpkins, rosemary, sage, st. augustinegrass, sunflowers, sweet corn, sweet peas, sweet potatoes, tall fescue, thyme, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
June
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, sweet potatoes, zinnias, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
Plant for fall: bearded irises, brussels sprouts, carrots, collard greens, lettuce, peas, snapdragons, swiss chard
August
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, spinach, tall fescue, tulips, turnips
October
Plant for fall: crocuses, daffodils, daylilies, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
November
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
December
Start indoors: onions
Frost dates and zones by ZIP code in Naperville
All 4 of Naperville's main ZIP codes take their frost dates from Aurora, so the dates on this page apply across the city. The hardiness zone is 5b in 60540, 60563, 60564, and 6a in 60565.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 60540 | 5b | Aurora, 1.5 mi NNE | Apr 19 | Oct 23 |
| 60563 | 5b | Aurora, 1.5 mi NNE | Apr 19 | Oct 23 |
| 60564 | 5b | Aurora, 1.5 mi NNE | Apr 19 | Oct 23 |
| 60565 | 6a | Aurora, 1.5 mi NNE | Apr 19 | Oct 23 |
Aurora also supplies the frost dates for Aurora and Bolingbrook, so their planting calendars match Naperville's.
Planting dates for popular crops in Naperville
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 20 to Apr 3 | May 15 to 29 | — |
| Strawberries | — | Mar 8 to 22 | — |
| Lettuce | Feb 22 to Mar 8 | Apr 12 to 26 | Jul 24 to Aug 28 |
| Cilantro | Mar 8 to 22 | Apr 19 to 26 | — |
| Basil | Mar 27 to Apr 10 | May 15 to 22 | — |
| Potatoes | — | Apr 17 to 24 | — |
| Garlic | — | Mar 8 to 22 | Oct 23 to Nov 6 |
| Onions | Dec 28 to Feb 8 | Mar 22 to Apr 5 | — |
| Cucumbers | Apr 17 to May 1 | May 15 to 29 | — |
| Pumpkins | Apr 17 to May 1 | May 15 to 29 | — |
| Peppers | Feb 27 to Mar 27 | May 15 to 29 | — |
| Carrots | — | Mar 29 to Apr 19 | Jul 31 to Aug 21 |
| Sweet Potatoes | — | May 30 to Jun 6 | — |
| Watermelons | Apr 10 to 24 | May 15 to 29 | — |
| Sweet Corn | — | Apr 19 to May 3 | — |
| Green Beans | — | May 15 to 29 | — |
| Zucchini | Apr 17 to May 1 | May 15 to 29 | — |
| Broccoli | Feb 1 to 22 | Mar 22 to Apr 5 | Aug 7 to Sep 4 |
| Peas | — | Mar 8 to 22 | Jul 31 to Aug 14 |
| Spinach | Mar 8 to 15 | Apr 12 to 26 | Aug 14 to Sep 18 |
| Sunflowers | — | Apr 19 to May 10 | — |
| Zinnias | May 17 to 24 | Jun 14 to 28 | — |
| Tulips | — | — | Sep 11 to Nov 6 |
| Daffodils | — | — | Sep 11 to Oct 23 |
| Grass Seed | — | Mar 8 to 22 | Sep 11 to 25 |
Nearby cities
- Bolingbrook, IL zone 6a, last frost Apr 19
- Aurora, IL zone 5b, last frost Apr 19
- Downers Grove, IL zone 6a, last frost Apr 27
- Wheaton, IL zone 5b, last frost Apr 27
- Plainfield, IL zone 5b, last frost Apr 19
- Joliet, IL zone 6a, last frost Apr 19
Planting in IllinoisAbout zone 5bPrintable calendar for Naperville
Questions
When is the last frost in Naperville?
Around April 19 in a typical year, based on NOAA's 1991-2020 records for Aurora. There is still a 1 in 10 chance of frost after May 4.
What planting zone is Naperville in?
USDA hardiness zone 5b (2023 map), with parts of the city in zone 6a. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Naperville?
Start seeds indoors March 20 to April 3 and set plants out May 15 to 29.
When is the first frost in Naperville?
Around October 23 in a typical year, and before October 9 about 1 year in 10.