USDA Hardiness Zone 5a
Frost Dates for 05491 — Vergennes, Vermont
NOAA 1991–2020 normals from Vergennes, VT (196 ft), 4 miles northeast.
Updated
In Vergennes, the last spring frost (32°F) is around April 30 in half of years and has passed by May 11 in nine years out of ten. The first fall frost comes around October 17, as early as October 2 one year in ten, leaving a typical freeze-free season of 168 days (NOAA, Vergennes, VT).
- Last spring frost
- April 30
- First fall frost
- October 17
- Growing season
- 168 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 25
- Last snow
- April 7
- Winters with snow
- 100%
- Snow per year
- 58.6"
median, 1991–2020
median, 1991–2020
24 of 24 observed
NOAA normal
Frost risk by date in Vergennes
Half of springs at Vergennes, VT see their last 32°F night by April 30; only one in ten is past it by April 20, and one in ten still has one after May 11. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 11 10%. The 11 days between the even-odds date and the one-in-ten date is the narrowest of the 41 Vermont stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 17 in half of years, as early as October 2 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 13 days later, around October 30; in spring the one-in-ten date for 28°F is May 2, 9 days before the 32°F one. The freeze-free season lasts 168 days in a typical year, longer than at 95% of the 41 Vermont stations; it reaches 187 days one year in ten and falls short of 149 one year in ten. On average 152 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 9 days longer, to about May 9, and return around October 5. Severe cold of 16°F or below comes every winter, usually between November 28 and March 25.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | May 2 | May 4 | May 7 | May 9 | May 12 | May 15 | May 18 | May 22 |
| 32°F | Apr 20 | Apr 24 | Apr 27 | Apr 29 | Apr 30 | May 2 | May 4 | May 7 | May 11 |
| 28°F | Apr 8 | Apr 13 | Apr 16 | Apr 18 | Apr 21 | Apr 23 | Apr 25 | Apr 29 | May 2 |
| 24°F | Mar 31 | Apr 3 | Apr 5 | Apr 7 | Apr 9 | Apr 12 | Apr 15 | Apr 17 | Apr 21 |
| 20°F | Mar 19 | Mar 24 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 5 | Apr 8 | Apr 12 |
| 16°F | Mar 12 | Mar 16 | Mar 19 | Mar 22 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 5 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 23 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 14 | Oct 18 |
| 32°F | Oct 2 | Oct 6 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 28°F | Oct 14 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 24°F | Oct 27 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 24 |
| 20°F | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Dec 3 |
| 16°F | Nov 14 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 3 | Dec 7 | Dec 12 |
Freeze probabilities 1991–2020 at Vergennes, VT, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 05491 →Compare Vergennes with another place →
Compared with the next station
The nearest other station, Cornwall, VT, 12 miles south of Vergennes, has a last frost 5 days later (May 5), a first frost 14 days earlier (October 3), a season 17 days shorter.
When it snows in Vergennes, Vermont
The first measurable snow (0.1 inch or more) in Vergennes usually arrives around November 25, and the last of the season around April 7. Those are the middle dates across the winters of 1991–2020 at Cornwall, VT, 12.3 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 23 days after the last snow.
Planting calendar for 05491
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 25 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 3 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 17 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 05491 is 4 miles from Vergennes, VT, which stands at 196 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 05491 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.