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USDA Hardiness Zone 7a

Frost Dates for 62087 — South Roxana, Illinois

Averages from Alton - Melvin Price L&D, Il US, the nearest reporting station, 5.5 miles away.

Plant tender crops after April 4, and expect the first autumn freeze around November 5. That leaves about 214 frost-free days.

Last spring frost
April 4

50% probability

First fall frost
November 5

50% probability

Growing season
214 days

frost-free

Hardiness zone
7a

0 to 5°F annual low

Planting calendar for 62087

What to do and when, based on the frost normals for South Roxana, Illinois
WhenWhat to do
January 24 – February 7

Start peppers and aubergines indoors

They need eight to ten weeks under lights before they can go out.

February 7 – February 21

Start tomatoes indoors

Six to eight weeks gives a transplant big enough to set fruit early.

March 7 – March 21

Sow peas, spinach, lettuce, radish outdoors

These tolerate light frost and prefer to germinate in cool soil.

April 4 onward

Transplant tomatoes, peppers, basil, squash, cucumbers

The average last freeze has passed — still watch the actual forecast.

by August 13

Sow the autumn crop of carrots, beets and brassicas

They need about twelve weeks to size up before growth stops.

by October 22

Harvest tender crops, or be ready to cover them

A first freeze two weeks early is well within normal variation.

November 5 onward

Plant garlic, mulch beds, lift tender bulbs

Garlic wants a cold spell; bare soil loses structure over winter.

What these dates mean

Wait until after April 4 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in South Roxana, Illinois are past their last freeze. Harvest before November 5, which leaves roughly 214 frost-free days.

ZIP 62087 sits in USDA hardiness zone 7a, meaning the average coldest night of the year falls between 0 to 5°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.

These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.

Other zone 7a ZIP codes in Illinois