🌷 Last Frost Dates for Ione, Washington 99139

The last 36°F Spring frost date is 30% likely to be on May 29. (See detailed probabilities below.)

The last 32°F light freeze date is 30% likely to be on May 12. (See detailed probabilities below.)

(See also 🍂 First Fall Frost Dates.)

Last frost date probabilities for Ione, WA are based on historical climate data.

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

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% chanceJun 8
20% chanceJun 2
30% chanceMay 29
40% chanceMay 26
50% chanceMay 22
60% chanceMay 19
70% chanceMay 15
80% chanceMay 11
90% chanceMay 7
Probability of light freeze (32°F) on or after…
10% chanceMay 23
20% chanceMay 17
30% chanceMay 12
40% chanceMay 8
50% chanceMay 5
60% chanceMay 2
70% chanceApr 30
80% chanceApr 27
90% chanceApr 22
Probability of moderate freeze (28°F) on or after…
10% chanceMay 4
20% chanceApr 30
30% chanceApr 26
40% chanceApr 22
50% chanceApr 18
60% chanceApr 14
70% chanceApr 11
80% chanceApr 6
90% chanceApr 1
Probability of moderate hard freeze (24°F) on or after…
10% chanceApr 19
20% chanceApr 11
30% chanceApr 6
40% chanceApr 2
50% chanceMar 31
60% chanceMar 28
70% chanceMar 23
80% chanceMar 18
90% chanceMar 12
Probability of hard freeze (20°F) on or after…
10% chanceApr 3
20% chanceMar 28
30% chanceMar 22
40% chanceMar 18
50% chanceMar 14
60% chanceMar 10
70% chanceMar 6
80% chanceMar 3
90% chanceFeb 25
Probability of severe hard freeze (16°F) on or after…
10% chanceMar 19
20% chanceMar 12
30% chanceMar 7
40% chanceMar 4
50% chanceMar 2
60% chanceFeb 28
70% chanceFeb 22
80% chanceFeb 17
90% chanceFeb 8

Agricultural climatic data from weather station: BOUNDARY DAM (USC00450844)