Frost dates for 11950Mastic, NY
The average last spring frost in Mastic is April 18 and the average first fall frost is October 28, giving a typical growing season of about 193 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Oct 28
- Growing season
- 193 days
Safer after May 1 (1-in-10 risk)
Possible by Oct 13 (1-in-10 risk)
Last frost typically in 166 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 · Apr 30 · May 15 | Oct 4 · Oct 17 · Nov 1 | 168 days | 100% |
| Frost / freeze (32°F) | Apr 4 · Apr 18 · May 1 | Oct 13 · Oct 28 · Nov 11 | 193 days | 100% |
| Hard freeze (28°F) | Mar 21 · Apr 3 · Apr 17 | Oct 24 · Nov 9 · Nov 25 | 218 days | 100% |
Planting calendar for Mastic
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 8 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 18 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 10 |
| Sweet corn | Sow outdoors | May 4 – Jul 8 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jun 28 – Jul 8 |
| Broccoli | Transplant outdoors (fall) | Jul 28 – Aug 8 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 18 – Jul 18 |
| Cabbage | Transplant outdoors (fall) | Jul 18 – Aug 18 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 18 – Sep 3 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 4 – Sep 8 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 18 – Sep 18 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 11 – Aug 18 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 18 – Aug 3 |
| Garlic | Plant outdoors (fall) | Oct 18 – Nov 18 |
Where these dates come from
ZIP code 11950 is matched to the NOAA station Shirley Brookhaven Ap, NY, 2 km away, at 82 ft elevation (30 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Shirley Brookhaven Ap, NY (used) | 82 ft | Apr 18 | Oct 28 |
| Upton Coop - Nwsfo New York, NY | 80 ft | Apr 21 | Oct 24 |
| Baiting Hollow, NY | 70 ft | Apr 24 | Oct 25 |
| Westhamptn Gabreski Ap, NY | 67 ft | May 7 | Oct 14 |
Frost dates near Mastic
- Shirley, NY 11967 · last Apr 18, first Oct 28
- Moriches, NY 11955 · last Apr 18, first Oct 28
- Brookhaven, NY 11719 · last Apr 18, first Oct 28
- Mastic Beach, NY 11951 · last Apr 18, first Oct 28
- Center Moriches, NY 11934 · last Apr 18, first Oct 28
- Yaphank, NY 11980 · last Apr 18, first Oct 28
- Manorville, NY 11949 · last Apr 18, first Oct 28
- Upton, NY 11973 · last Apr 18, first Oct 28
Frequently asked questions
- When is the last frost in Mastic, NY?
- For ZIP code 11950, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Shirley Brookhaven Ap, NY weather station. There is a 1-in-10 chance of a frost after May 1.
- When is the first frost in Mastic, NY?
- The average first fall frost (32°F) is October 28. There is a 1-in-10 chance of frost by October 13, so tender plants are at risk from that point on.
- How long is the growing season in 11950?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 193 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.