🌷 Your Ultimate Garden Calendar!

🌷 Last Frost Dates for Saint Helena, California 94574

The last 36°F Spring frost date is 30% likely to be on May 12. (See detailed probabilities below.)

The last 32°F light freeze date is 30% likely to be on Apr 20. (See detailed probabilities below.)

(See also 🍂 First Fall Frost Dates.)

Last frost date probabilities for Saint Helena, CA are based on historical climate data.

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

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What is a Last Frost Date?

The last spring frost signals when your area is safe from freezing temperatures. Tender plants can now grow outdoors without cold damage! This marks the beginning of the growing season. Last spring frost serves as your essential starting point for planting warm-season crops. It's also time to remove winter protection from your perennials. Enjoy the longer days and warmer weather!

How to use the Last Frost Date?

Start seeds indoors several weeks before your last frost date. This gives plants time to reach transplanting size when weather permits. Plan your outdoor planting schedule around your area's average last frost date. Plant some crops before and some after this date to protect against weather changes. Look for spots in your yard where frost stays longer or disappears earlier. Create your own frost map to use all available growing space and extend your season. Keep watching your local weather forecast to catch any surprise late frosts.

Last Frost Date Probabilities

Probability of frost (36°F) on or after…
10% chanceMay 26
20% chanceMay 18
30% chanceMay 12
40% chanceMay 6
50% chanceMay 2
60% chanceApr 28
70% chanceApr 24
80% chanceApr 18
90% chanceApr 9
Probability of light freeze (32°F) on or after…
10% chanceMay 4
20% chanceApr 27
30% chanceApr 20
40% chanceApr 15
50% chanceApr 8
60% chanceMar 31
70% chanceMar 23
80% chanceMar 12
90% chanceFeb 20
Probability of moderate freeze (28°F) on or after…
10% chanceApr 12
20% chanceApr 1
30% chanceMar 21
40% chanceMar 11
50% chanceFeb 26
60% chanceFeb 5
70% chanceJan 21
80% chanceJan 7
90% chanceDec 24
Probability of moderate hard freeze (24°F) on or after…
10% chanceMar 17
20% chanceFeb 28
30% chanceFeb 15
40% chanceJan 26
50% chanceJan 4
60% chanceDec 29
70% chanceDec 24
80% chanceDec 18
90% chanceDec 12
Probability of hard freeze (20°F) on or after…
10% chancerarely
20% chancerarely
30% chancerarely
40% chancerarely
50% chancerarely
60% chancerarely
70% chancerarely
80% chancerarely
90% chancerarely
Probability of severe hard freeze (16°F) on or after…
10% chancerarely
20% chancerarely
30% chancerarely
40% chancerarely
50% chancerarely
60% chancerarely
70% chancerarely
80% chancerarely
90% chancerarely

Agricultural climatic data from weather station: ANGWIN PAC UNION COL (USC00040212)

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