Last frost date in Belleville, IL
Expect the last frost in Belleville around April 12. Frost after April 28 happens in only one year out of ten. The first fall frost usually arrives about October 20, which leaves 189 frost-free days. An early freeze before October 3 happens one year in ten.
- Safe after (10% risk)
- Apr 28
- Average first frost
- Oct 20
- Frost-free season
- 189 days
- Hard freeze (28°F) ends
- Mar 31
No frost in the next 7 nights
Later than usual: the average first frost here is October 20.
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2247°
- FriOct 2346°
- SatOct 2448°
- SunOct 2550°
- MonOct 2650°
- TueOct 2747°
- WedOct 2848°
Planting calendar for Belleville
Windows count forward or back from the average frost dates above. Click a crop for dates across Illinois.
TomatoesApr 19–May 3
PumpkinsApr 26–May 10
SunflowersApr 12–May 3
CucumbersApr 26–May 3
CornApr 19–May 3
Sweet potatoesMay 3–May 17
WatermelonApr 26–May 10
Green beansApr 19–May 10
ZucchiniApr 19–May 3
OkraMay 3–May 17
PeppersApr 26–May 10
BasilApr 19–May 3
Butternut squashApr 19–May 3
CantaloupeApr 26–May 10
EggplantApr 26–May 10
PotatoesMar 15–Mar 29
OnionsMar 1–Mar 22
CarrotsMar 22–Apr 26
LettuceMar 29–Apr 19
BroccoliMar 15–Mar 29
BeetsMar 15–Apr 26
PeasMar 1–Mar 15
CabbageMar 15–Mar 29
RadishesMar 8–Apr 19
Brussels sproutsMar 29–Apr 12
SpinachMar 1–Mar 22
CilantroMar 29–Apr 19
KaleMar 15–Mar 29
Collard greensMar 15–Mar 29
TurnipsMar 15–Mar 29
DillApr 12–Apr 26
CeleryApr 19–Apr 26
CauliflowerMar 29–Apr 12
LeeksMar 29–Apr 12
Swiss chardMar 29–Apr 26
ParsleyMar 29–Apr 19
Tulip bulbsOct 6–Nov 10
GarlicSep 29–Nov 3
Daffodil bulbsSep 22–Nov 3
StrawberriesMar 15–Mar 29
AsparagusMar 15–Mar 29Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Mar 28 | Apr 12 | Apr 28 | Oct 3 | Oct 20 | Nov 1 |
| Hard freeze, 28°F | Mar 14 | Mar 31 | Apr 16 | Oct 15 | Oct 30 | Nov 15 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Belleville Siu Rsch (USW00013802) sits 7.7 miles from the center of Belleville at 450 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Belleville, IL?
The average last frost date in Belleville is April 12, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 28.
When is the first frost in Belleville?
The first frost in fall usually comes around October 20. One year in ten it arrives before October 3.
How long is the growing season in Belleville?
About 189 days between the average last and first frost.
When should I plant tomatoes in Belleville?
Plant tomato seedlings outside from April 19 to May 3. Start seeds indoors six to eight weeks earlier.
Nearby in Illinois
- O'FallonApr 12
- CollinsvilleApr 8
- Granite CityApr 4
- EdwardsvilleApr 4
- AltonApr 4
- CarbondaleApr 9
- SpringfieldApr 15
- DecaturApr 14
- QuincyApr 8
- PekinApr 16
- ChampaignApr 15
- BloomingtonApr 25