First Frost & Freeze Dates for Berwyn Heights/College Park/Greenbelt
Predicting first frost or freeze dates is like predicting next months weather -- Good luck with that. What we have are estimates based on historical data. In another blog post I discussed the last frost or freeze dates. Well, the same reasoning applies to this estimate of the first frost or freeze dates. These dates are published by the National Gardening Association for the College Park ZIP Code 20740.
| Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
| First 16° | 1-Dec | 7-Dec | 11-Dec | 14-Dec | 18-Dec | 21-Dec | 24-Dec | 29-Dec | 3-Jan |
| First 20° | 17-Nov | 24-Nov | 29-Nov | 3-Dec | 7-Dec | 11-Dec | 16-Dec | 21-Dec | 28-Dec |
| First 24° | 2-Nov | 7-Nov | 11-Nov | 15-Nov | 18-Nov | 21-Nov | 25-Nov | 29-Nov | 4-Dec |
| First 28° | 16-Oct | 21-Oct | 24-Oct | 28-Oct | 30-Oct | 2-Nov | 5-Nov | 9-Nov | 14-Nov |
| First 32° | 9-Oct | 13-Oct | 17-Oct | 19-Oct | 22-Oct | 25-Oct | 27-Oct | 31-Oct | 4-Nov |
| First 36° | 30-Sep | 4-Oct | 7-Oct | 10-Oct | 12-Oct | 15-Oct | 17-Oct | 20-Oct | 25-Oct |
So, on average the 50/50 chance of first frost (30 degree temperature) occurs on October 12 and the 90% chance of frost occurs on October 25. Can you get your remaining vegetables harvested before the first frost or freeze. Covering your plants overnight with frost blanket or old sheet can buy you a degree or two of protection. Instead of frost fabric, I use inexpensive twin-sized fleece blankets that I bought expressly to protect plants from frost and freezing.