Frost dates for 61021Dixon, IL
The average last spring frost in Dixon is April 21 and the average first fall frost is October 19, giving a typical growing season of about 180 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 21
- Average first fall frost
- Oct 19
- Growing season
- 180 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 4 (1-in-10 risk)
Last frost typically in 173 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 18 · May 2 · May 16 | Sep 24 · Oct 9 · Oct 22 | 158 days | 100% |
| Frost / freeze (32°F) | Apr 7 · Apr 21 · May 5 | Oct 4 · Oct 19 · Oct 30 | 180 days | 100% |
| Hard freeze (28°F) | Mar 27 · Apr 10 · Apr 26 | Oct 17 · Oct 30 · Nov 12 | 201 days | 100% |
Planting calendar for Dixon
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 21 – May 27 |
| Tomatoes | Transplant outdoors | May 7 – Jun 29 |
| Peppers | Start seeds indoors | Mar 21 – Apr 21 |
| Peppers | Transplant outdoors | May 21 – Jun 21 |
| Eggplant | Start seeds indoors | Apr 7 – May 6 |
| Eggplant | Transplant outdoors | May 21 – Jun 21 |
| Cucumbers | Sow outdoors | May 21 – Jul 9 |
| Summer squash | Sow outdoors | May 7 – Jun 21 |
| Winter squash & pumpkins | Sow outdoors | May 21 – Jun 21 |
| Snap beans | Sow outdoors | May 7 – Aug 1 |
| Sweet corn | Sow outdoors | May 7 – Jun 29 |
| Watermelon & cantaloupe | Sow outdoors | May 21 – Jun 21 |
| Okra | Sow outdoors | May 14 – Jun 6 |
| Peas | Sow outdoors (spring) | Mar 21 – May 6 |
| Potatoes | Plant outdoors (spring) | Mar 21 – May 21 |
| Onions | Start seeds indoors (spring) | Feb 7 – Mar 6 |
| Onions | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (spring) | Mar 3 – Apr 6 |
| Broccoli | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (fall) | Jun 19 – Jun 29 |
| Broccoli | Transplant outdoors (fall) | Jul 19 – Jul 30 |
| Cabbage | Start seeds indoors (spring) | Feb 21 – Mar 21 |
| Cabbage | Transplant outdoors (spring) | Mar 21 – Apr 21 |
| Cabbage | Start seeds indoors (fall) | Jun 9 – Jul 9 |
| Cabbage | Transplant outdoors (fall) | Jul 9 – Aug 9 |
| Leaf lettuce | Sow outdoors (spring) | Mar 21 – Jun 6 |
| Leaf lettuce | Sow outdoors (fall) | Jul 9 – Aug 25 |
| Spinach | Sow outdoors (spring) | Mar 14 – Apr 27 |
| Spinach | Sow outdoors (fall) | Jul 26 – Aug 30 |
| Radishes | Sow outdoors (spring) | Mar 21 – May 11 |
| Radishes | Sow outdoors (fall) | Jul 9 – Sep 9 |
| Kale | Sow outdoors (spring) | Apr 7 – Apr 27 |
| Kale | Sow outdoors (fall) | Jul 2 – Aug 9 |
| Carrots | Sow outdoors (spring) | Apr 21 – Jun 6 |
| Carrots | Sow outdoors (fall) | Jun 9 – Jul 25 |
| Garlic | Plant outdoors (fall) | Oct 9 – Nov 9 |
Where these dates come from
ZIP code 61021 is matched to the NOAA station Dixon 1W, IL, 2.5 km away, at 660 ft elevation (3 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Dixon 1W, IL (used) | 660 ft | Apr 21 | Oct 19 |
| Polo 5Nw, IL | 856 ft | Apr 29 | Oct 7 |
| Walnut, IL | 671 ft | Apr 24 | Oct 14 |
| Rochelle, IL | 775 ft | Apr 26 | Oct 13 |
Frost dates near Dixon
- Woosung, IL 61091 · last Apr 21, first Oct 19
- Nachusa, IL 61057 · last Apr 21, first Oct 19
- Eldena, IL 61324 · last Apr 21, first Oct 19
- Franklin Grove, IL 61031 · last Apr 26, first Oct 13
- Harmon, IL 61042 · last Apr 24, first Oct 14
- Polo, IL 61064 · last Apr 29, first Oct 7
- Sterling, IL 61081 · last Apr 21, first Oct 19
- Rock Falls, IL 61071 · last Apr 21, first Oct 19
Frequently asked questions
- When is the last frost in Dixon, IL?
- For ZIP code 61021, the average last spring frost (32°F) is April 21, based on NOAA 1991-2020 climate normals for the Dixon 1W, IL weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Dixon, IL?
- The average first fall frost (32°F) is October 19. There is a 1-in-10 chance of frost by October 4, so tender plants are at risk from that point on.
- How long is the growing season in 61021?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 180 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.