USDA Hardiness Zone 7a
Frost Dates for 62233 — Chester, Illinois
Averages from Kaskaskia Rvr Navigation Lock, Il US, the nearest reporting station, 7.7 miles away.
Plant tender crops after April 8, and expect the first autumn freeze around October 30. That leaves about 202 frost-free days.
- Last spring frost
- April 8
- First fall frost
- October 30
- Growing season
- 202 days
- Hardiness zone
- 7a
50% probability
50% probability
frost-free
0 to 5°F annual low
- First snow
- December 22
- Last snow
- February 24
- Winters with snow
- 100%
- Snow per year
- 12"
median, 1991–2020
median, 1991–2020
23 of 23 observed
NOAA normal
When it snows in Chester, Illinois
The first measurable snow (0.1 inch or more) in Chester, Illinois usually arrives around December 22, and the last of the season around February 24. Those are the middle dates across the winters of 1991–2020 at Chester, Il US, 1.4 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow.
For a gardener, snow matters less than frost: a light snow on frozen ground changes nothing, while a hard frost on an unprotected bed ends the season. Use the frost dates above for planting and the snow dates for getting hoses drained, mulch down and tender pots indoors.
Planting calendar for 62233
| When | What to do |
|---|---|
| January 28 – February 11 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| February 11 – February 25 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| March 11 – March 25 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| April 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by August 7 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by October 16 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| October 30 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 8 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Chester, Illinois are past their last freeze. Harvest before October 30, which leaves roughly 202 frost-free days.
ZIP 62233 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.