USDA Hardiness Zone 7a
Frost Dates for 20111 — Manassas Park, Virginia
NOAA 1991–2020 normals from Manassas, VA (245 ft), 3 miles southwest.
Updated
In Manassas Park, the last spring frost (32°F) is around April 12 in half of years and has passed by April 24 in nine years out of ten. The first fall frost comes around October 27, as early as October 13 one year in ten, leaving a typical freeze-free season of 197 days (NOAA, Manassas, VA).
- Last spring frost
- April 12
- First fall frost
- October 27
- Growing season
- 197 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- December 14
- Last snow
- March 14
- Winters with snow
- 100%
- Snow per year
- 21"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Manassas Park
Half of springs at Manassas, VA see their last 32°F night by April 12; only one in ten is past it by March 30, and one in ten still has one after April 24. Planting tender crops after April 17 leaves a 30% risk of a frost on them, after April 20 20%, and after April 24 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 97% of the 128 Virginia stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 27 in half of years, as early as October 13 one year in ten, and holds off past November 7 one year in ten. A hard freeze of 28°F follows 9 days later, around November 5; in spring the one-in-ten date for 28°F is April 14, 10 days before the 32°F one. The freeze-free season lasts 197 days in a typical year, shorter than at 50% of the 128 Virginia stations; it reaches 216 days one year in ten and falls short of 180 one year in ten. On average 94 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 12 days longer, to about April 24, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 20 and February 28.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 4 | May 10 |
| 32°F | Mar 30 | Apr 3 | Apr 7 | Apr 9 | Apr 12 | Apr 15 | Apr 17 | Apr 20 | Apr 24 |
| 28°F | Mar 17 | Mar 22 | Mar 27 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 14 |
| 24°F | Mar 2 | Mar 9 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 28 | Mar 31 | Apr 4 |
| 20°F | Feb 20 | Feb 26 | Mar 2 | Mar 6 | Mar 9 | Mar 12 | Mar 15 | Mar 19 | Mar 25 |
| 16°F | Feb 4 | Feb 13 | Feb 19 | Feb 23 | Feb 28 | Mar 2 | Mar 5 | Mar 10 | Mar 15 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 6 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 26 | Oct 30 |
| 32°F | Oct 13 | Oct 18 | Oct 22 | Oct 25 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 7 |
| 28°F | Oct 24 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
| 24°F | Nov 2 | Nov 7 | Nov 10 | Nov 14 | Nov 16 | Nov 19 | Nov 23 | Nov 28 | Dec 4 |
| 20°F | Nov 13 | Nov 18 | Nov 22 | Nov 26 | Dec 1 | Dec 5 | Dec 10 | Dec 16 | Dec 24 |
| 16°F | Nov 27 | Dec 4 | Dec 9 | Dec 14 | Dec 20 | Dec 25 | Dec 30 | Jan 3 | Jan 12 |
Freeze probabilities 1991–2020 at Manassas, VA, 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 20111 →Compare Manassas Park with another place →
Compared with the next station
The nearest other station, Washington Dc Dulles Airport, VA, 12 miles north of Manassas Park, has a last frost 3 days later (April 15), a first frost 3 days earlier (October 24), a season 3 days shorter.
When it snows in Manassas Park, Virginia
The first measurable snow (0.1 inch or more) in Manassas Park usually arrives around December 14, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Washington Dc Dulles Airport, VA, 11.8 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 29 days after the last snow.
Planting calendar for 20111
| When | What to do |
|---|---|
| February 1 – February 15 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 15 – March 1 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 15 – March 29 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 12 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 4 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 27 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 20111 is 3 miles from Manassas, VA, which stands at 245 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 22193 (Woodbridge). The 2023 USDA Plant Hardiness Zone Map lists ZIP 20111 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°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.