🌷 Your Ultimate Garden Calendar!

🍂 First Frost Dates for Harwich, Massachusetts 02645

The first 36°F frost date is 30% likely to be on Oct 15. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Oct 28. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Harwich, MA are based on historical climate data.

Always check your local forecast for the most up-to-date frost warnings.

Book Recommendations (ads!)

📚 Growing Under Cover: Techniques for a More Productive, Weather-Resistant, Pest-Free Vegetable Garden

📚 Greenhouse Gardening for Beginners: Step By Step Guide To Build A Year-Round Greenhouse And Grow Herbs, Organic Fruits And Vegetables, Plants, Flowers Plans & Ideas for Extending the Growing Season

📚 How to Garden Indoors & Grow Your Own Food Year Round: Ultimate Guide to Vertical, Container, and Hydroponic Gardening (Creative Homeowner) Vegetables, Herbs, DIY Projects, Composting, Lights, & More

📚 The Year-Round Vegetable Gardener: How to Grow Your Own Food 365 Days a Year, No Matter Where You Live

What is a First Frost Date?

The first fall frost signals the end of your local growing season. This date serves as an important deadline for gardeners and farmers. You'll need to complete harvesting before this point. Annuals and other tender plants will die back when frost hits, and perennial plants will enter their dormant phase for winter. Meanwhile, it's time to enjoy a cup of hot cocoa and a cozy sweater—and start planning your spring garden!

How to use the First Frost Date?

Watch your local weather forecasts in early fall to predict the first frost date. Harvest tender crops and protect vulnerable plants before frost arrives. For late-summer plantings, count backward from your area's average first frost date. This ensures your crops have enough time to mature. Keep track of when frost actually occurs in your garden each year. This helps you identify protected spots where the growing season might last longer.

First Frost Date Probabilities

Probability of frost (36°F) on or before...
10% chanceOct 8
20% chanceOct 12
30% chanceOct 15
40% chanceOct 18
50% chanceOct 21
60% chanceOct 23
70% chanceOct 26
80% chanceOct 29
90% chanceNov 2
Probability of light freeze (32°F) on or before...
10% chanceOct 19
20% chanceOct 24
30% chanceOct 28
40% chanceOct 31
50% chanceNov 2
60% chanceNov 4
70% chanceNov 8
80% chanceNov 12
90% chanceNov 18
Probability of moderate freeze (28°F) on or before...
10% chanceNov 2
20% chanceNov 7
30% chanceNov 11
40% chanceNov 15
50% chanceNov 18
60% chanceNov 21
70% chanceNov 25
80% chanceNov 30
90% chanceDec 4
Probability of moderate hard freeze (24°F) on or before...
10% chanceNov 16
20% chanceNov 22
30% chanceNov 26
40% chanceNov 30
50% chanceDec 2
60% chanceDec 5
70% chanceDec 8
80% chanceDec 12
90% chanceDec 18
Probability of hard freeze (20°F) on or before...
10% chanceNov 29
20% chanceDec 2
30% chanceDec 6
40% chanceDec 10
50% chanceDec 14
60% chanceDec 18
70% chanceDec 21
80% chanceDec 26
90% chanceJan 1
Probability of severe hard freeze (16°F) on or before...
10% chanceDec 7
20% chanceDec 14
30% chanceDec 20
40% chanceDec 23
50% chanceDec 28
60% chanceJan 1
70% chanceJan 5
80% chanceJan 10
90% chanceJan 18

Agricultural climatic data from weather station: CHATHAM MUNI AP (USW00094624)

Back to Weather Calendar