Frost dates for 21215Baltimore, MD
The average last spring frost in Baltimore is April 2 and the average first fall frost is November 7, giving a typical growing season of about 220 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Nov 7
- Growing season
- 220 days
Safer after Apr 13 (1-in-10 risk)
Possible by Oct 27 (1-in-10 risk)
First frost typically in 4 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 2 · Apr 14 · May 1 | Oct 13 · Oct 27 · Nov 9 | 195 days | 100% |
| Frost / freeze (32°F) | Mar 20 · Apr 2 · Apr 13 | Oct 27 · Nov 7 · Nov 21 | 220 days | 100% |
| Hard freeze (28°F) | Mar 8 · Mar 22 · Apr 3 | Nov 6 · Nov 20 · Dec 7 | 243 days | 100% |
Planting calendar for Baltimore
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 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 18 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Jul 28 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 20 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 18 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 8 – Jul 18 |
| Broccoli | Transplant outdoors (fall) | Aug 7 – Aug 18 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jun 28 – Jul 28 |
| Cabbage | Transplant outdoors (fall) | Jul 28 – Aug 28 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 28 – Sep 13 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 14 – Sep 18 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Jul 28 – Sep 28 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 21 – Aug 28 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jun 28 – Aug 13 |
| Garlic | Plant outdoors (fall) | Oct 28 – Nov 28 |
Where these dates come from
ZIP code 21215 is matched to the NOAA station Cylburn, MD, 2.4 km away, at 235 ft elevation (198 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cylburn, MD (used) | 235 ft | Apr 2 | Nov 7 |
| Md Sci Ctr Baltimore, MD | 20 ft | Mar 24 | Nov 21 |
| Baltimore Wash Intl Ap, MD | 156 ft | Apr 10 | Oct 31 |
| Laurel 3 W, MD | 400 ft | Apr 5 | Nov 9 |
Frost dates near Baltimore
- Baltimore, MD 21209 · last Apr 2, first Nov 7
- Pikesville, MD 21282 · last Apr 2, first Nov 7
- Gwynn Oak, MD 21207 · last Mar 24, first Nov 21
- Brooklandville, MD 21022 · last Apr 2, first Nov 7
- Riderwood, MD 21139 · last Apr 2, first Nov 7
- Stevenson, MD 21153 · last Apr 2, first Nov 7
- Catonsville, MD 21228 · last Apr 10, first Oct 31
- Windsor Mill, MD 21244 · last Apr 10, first Oct 31
Frequently asked questions
- When is the last frost in Baltimore, MD?
- For ZIP code 21215, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the Cylburn, MD weather station. There is a 1-in-10 chance of a frost after April 13.
- When is the first frost in Baltimore, MD?
- The average first fall frost (32°F) is November 7. There is a 1-in-10 chance of frost by October 27, so tender plants are at risk from that point on.
- How long is the growing season in 21215?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 220 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.