Frost dates for 60546Riverside, IL
The average last spring frost in Riverside is April 11 and the average first fall frost is October 31, giving a typical growing season of about 201 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 11
- Average first fall frost
- Oct 31
- Growing season
- 201 days
Safer after Apr 27 (1-in-10 risk)
Possible by Oct 20 (1-in-10 risk)
First frost typically in 1 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 9 · Apr 23 · May 8 | Oct 8 · Oct 21 · Nov 1 | 180 days | 100% |
| Frost / freeze (32°F) | Mar 30 · Apr 11 · Apr 27 | Oct 20 · Oct 31 · Nov 14 | 201 days | 100% |
| Hard freeze (28°F) | Mar 15 · Apr 1 · Apr 14 | Oct 31 · Nov 11 · Nov 26 | 225 days | 100% |
Planting calendar for Riverside
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 11 – May 17 |
| Tomatoes | Transplant outdoors | Apr 27 – Jul 11 |
| Peppers | Start seeds indoors | Mar 11 – Apr 11 |
| Peppers | Transplant outdoors | May 11 – Jun 11 |
| Eggplant | Start seeds indoors | Mar 28 – Apr 26 |
| Eggplant | Transplant outdoors | May 11 – Jun 11 |
| Cucumbers | Sow outdoors | May 11 – Jul 21 |
| Summer squash | Sow outdoors | Apr 27 – Jun 11 |
| Winter squash & pumpkins | Sow outdoors | May 11 – Jun 11 |
| Snap beans | Sow outdoors | Apr 27 – Aug 13 |
| Sweet corn | Sow outdoors | Apr 27 – Jul 11 |
| Watermelon & cantaloupe | Sow outdoors | May 11 – Jun 11 |
| Okra | Sow outdoors | May 4 – May 27 |
| Peas | Sow outdoors (spring) | Mar 11 – Apr 26 |
| Potatoes | Plant outdoors (spring) | Mar 11 – May 11 |
| Onions | Start seeds indoors (spring) | Jan 28 – Feb 24 |
| Onions | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (spring) | Feb 21 – Mar 27 |
| Broccoli | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (fall) | Jul 1 – Jul 11 |
| Broccoli | Transplant outdoors (fall) | Jul 31 – Aug 11 |
| Cabbage | Start seeds indoors (spring) | Feb 11 – Mar 11 |
| Cabbage | Transplant outdoors (spring) | Mar 11 – Apr 11 |
| Cabbage | Start seeds indoors (fall) | Jun 21 – Jul 21 |
| Cabbage | Transplant outdoors (fall) | Jul 21 – Aug 21 |
| Leaf lettuce | Sow outdoors (spring) | Mar 11 – May 27 |
| Leaf lettuce | Sow outdoors (fall) | Jul 21 – Sep 6 |
| Spinach | Sow outdoors (spring) | Mar 4 – Apr 17 |
| Spinach | Sow outdoors (fall) | Aug 7 – Sep 11 |
| Radishes | Sow outdoors (spring) | Mar 11 – May 1 |
| Radishes | Sow outdoors (fall) | Jul 21 – Sep 21 |
| Kale | Sow outdoors (spring) | Mar 28 – Apr 17 |
| Kale | Sow outdoors (fall) | Jul 14 – Aug 21 |
| Carrots | Sow outdoors (spring) | Apr 11 – May 27 |
| Carrots | Sow outdoors (fall) | Jun 21 – Aug 6 |
| Garlic | Plant outdoors (fall) | Oct 21 – Nov 21 |
Where these dates come from
ZIP code 60546 is matched to the NOAA station Chicago Midway Ap, IL, 8.1 km away, at 612 ft elevation (8 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chicago Midway Ap, IL (used) | 612 ft | Apr 11 | Oct 31 |
| Chicago Midway Ap 3Sw, IL | 620 ft | Apr 10 | Nov 1 |
| Little Red School Hse, IL | 715 ft | Apr 19 | Oct 22 |
| Chicago Northerly Is, IL | 583 ft | Apr 10 | Nov 5 |
Frost dates near Riverside
- Berwyn, IL 60402 · last Apr 11, first Oct 31
- Lyons, IL 60534 · last Apr 11, first Oct 31
- Brookfield, IL 60513 · last Apr 11, first Oct 31
- Hines, IL 60141 · last Apr 11, first Oct 31
- Broadview, IL 60155 · last Apr 11, first Oct 31
- Forest Park, IL 60130 · last Apr 11, first Oct 31
- La Grange Park, IL 60526 · last Apr 11, first Oct 31
- Oak Park, IL 60304 · last Apr 11, first Oct 31
Frequently asked questions
- When is the last frost in Riverside, IL?
- For ZIP code 60546, the average last spring frost (32°F) is April 11, based on NOAA 1991-2020 climate normals for the Chicago Midway Ap, IL weather station. There is a 1-in-10 chance of a frost after April 27.
- When is the first frost in Riverside, IL?
- The average first fall frost (32°F) is October 31. There is a 1-in-10 chance of frost by October 20, so tender plants are at risk from that point on.
- How long is the growing season in 60546?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 201 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.