Frost dates for 62012Brighton, IL
The average last spring frost in Brighton is April 14 and the average first fall frost is October 19, giving a typical growing season of about 187 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 14
- Average first fall frost
- Oct 19
- Growing season
- 187 days
Safer after Apr 30 (1-in-10 risk)
Possible by Oct 7 (1-in-10 risk)
Last frost typically in 167 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 12 · Apr 26 · May 10 | Sep 26 · Oct 11 · Oct 22 | 166 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 14 · Apr 30 | Oct 7 · Oct 19 · Nov 1 | 187 days | 100% |
| Hard freeze (28°F) | Mar 19 · Apr 4 · Apr 19 | Oct 18 · Oct 30 · Nov 14 | 208 days | 100% |
Planting calendar for Brighton
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 14 – May 20 |
| Tomatoes | Transplant outdoors | Apr 30 – Jun 29 |
| Peppers | Start seeds indoors | Mar 14 – Apr 14 |
| Peppers | Transplant outdoors | May 14 – Jun 14 |
| Eggplant | Start seeds indoors | Mar 31 – Apr 29 |
| Eggplant | Transplant outdoors | May 14 – Jun 14 |
| Cucumbers | Sow outdoors | May 14 – Jul 9 |
| Summer squash | Sow outdoors | Apr 30 – Jun 14 |
| Winter squash & pumpkins | Sow outdoors | May 14 – Jun 14 |
| Snap beans | Sow outdoors | Apr 30 – Aug 1 |
| Sweet corn | Sow outdoors | Apr 30 – Jun 29 |
| Watermelon & cantaloupe | Sow outdoors | May 14 – Jun 14 |
| Okra | Sow outdoors | May 7 – May 30 |
| Peas | Sow outdoors (spring) | Mar 14 – Apr 29 |
| Potatoes | Plant outdoors (spring) | Mar 14 – May 14 |
| Onions | Start seeds indoors (spring) | Jan 31 – Feb 27 |
| Onions | Transplant outdoors (spring) | Mar 31 – Apr 29 |
| Broccoli | Start seeds indoors (spring) | Feb 24 – Mar 30 |
| Broccoli | Transplant outdoors (spring) | Mar 31 – Apr 29 |
| Broccoli | Start seeds indoors (fall) | Jun 19 – Jun 29 |
| Broccoli | Transplant outdoors (fall) | Jul 19 – Jul 30 |
| Cabbage | Start seeds indoors (spring) | Feb 14 – Mar 14 |
| Cabbage | Transplant outdoors (spring) | Mar 14 – Apr 14 |
| Cabbage | Start seeds indoors (fall) | Jun 9 – Jul 9 |
| Cabbage | Transplant outdoors (fall) | Jul 9 – Aug 9 |
| Leaf lettuce | Sow outdoors (spring) | Mar 14 – May 30 |
| Leaf lettuce | Sow outdoors (fall) | Jul 9 – Aug 25 |
| Spinach | Sow outdoors (spring) | Mar 7 – Apr 20 |
| Spinach | Sow outdoors (fall) | Jul 26 – Aug 30 |
| Radishes | Sow outdoors (spring) | Mar 14 – May 4 |
| Radishes | Sow outdoors (fall) | Jul 9 – Sep 9 |
| Kale | Sow outdoors (spring) | Mar 31 – Apr 20 |
| Kale | Sow outdoors (fall) | Jul 2 – Aug 9 |
| Carrots | Sow outdoors (spring) | Apr 14 – May 30 |
| Carrots | Sow outdoors (fall) | Jun 9 – Jul 25 |
| Garlic | Plant outdoors (fall) | Oct 9 – Nov 9 |
Where these dates come from
ZIP code 62012 is matched to the NOAA station Jerseyville 2 Sw, IL, 18.7 km away, at 630 ft elevation (30 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Jerseyville 2 Sw, IL (used) | 630 ft | Apr 14 | Oct 19 |
| Alton - Melvin Price L&D, IL | 405 ft | Apr 4 | Nov 5 |
| St Charles Co Ap, MO | 436 ft | Apr 5 | Oct 27 |
| Carlinville, IL | 621 ft | Apr 14 | Oct 21 |
Frost dates near Brighton
- Piasa, IL 62079 · last Apr 14, first Oct 19
- Godfrey, IL 62035 · last Apr 4, first Nov 5
- Fidelity, IL 62030 · last Apr 14, first Oct 19
- Dow, IL 62022 · last Apr 14, first Oct 19
- Alton, IL 62002 · last Apr 4, first Nov 5
- Cottage Hills, IL 62018 · last Apr 4, first Nov 5
- Dorsey, IL 62021 · last Apr 4, first Nov 5
- Bunker Hill, IL 62014 · last Apr 14, first Oct 21
Frequently asked questions
- When is the last frost in Brighton, IL?
- For ZIP code 62012, the average last spring frost (32°F) is April 14, based on NOAA 1991-2020 climate normals for the Jerseyville 2 Sw, IL weather station. There is a 1-in-10 chance of a frost after April 30.
- When is the first frost in Brighton, IL?
- The average first fall frost (32°F) is October 19. There is a 1-in-10 chance of frost by October 7, so tender plants are at risk from that point on.
- How long is the growing season in 62012?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 187 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.