USDA Hardiness Zone 6b
Frost Dates for 63390 — Wright City, Missouri
NOAA 1991–2020 normals from Warrenton 1 N, MO (827 ft), 6 miles northwest.
Updated
In Wright City, the last spring frost (32°F) is around April 14 in half of years and has passed by May 3 in nine years out of ten. The first fall frost comes around October 23, as early as October 9 one year in ten, leaving a typical freeze-free season of 191 days (NOAA, Warrenton 1 N, MO).
- Last spring frost
- April 14
- First fall frost
- October 23
- Growing season
- 191 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 29
- Last snow
- February 24
- Winters with snow
- 96%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
26 of 27 observed
NOAA normal
Frost risk by date in Wright City
Half of springs at Warrenton 1 N, MO see their last 32°F night by April 14; only one in ten is past it by March 31, and one in ten still has one after May 3. Planting tender crops after April 22 leaves a 30% risk of a frost on them, after April 27 20%, and after May 3 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 92% of the 158 Missouri stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 23 in half of years, as early as October 9 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 10 days later, around November 2; in spring the one-in-ten date for 28°F is April 18, 15 days before the 32°F one. The freeze-free season lasts 191 days in a typical year, shorter than at 60% of the 158 Missouri stations; it reaches 212 days one year in ten and falls short of 169 one year in ten. On average 111 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 14 days longer, to about April 28, and return around October 14. Severe cold of 16°F or below comes every winter, usually between December 4 and March 3.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 11 | Apr 16 | Apr 20 | Apr 24 | Apr 28 | May 1 | May 5 | May 9 | May 14 |
| 32°F | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 14 | Apr 18 | Apr 22 | Apr 27 | May 3 |
| 28°F | Mar 17 | Mar 24 | Mar 28 | Mar 31 | Apr 3 | Apr 5 | Apr 8 | Apr 12 | Apr 18 |
| 24°F | Mar 6 | Mar 12 | Mar 17 | Mar 21 | Mar 24 | Mar 28 | Mar 31 | Apr 3 | Apr 9 |
| 20°F | Feb 23 | Mar 1 | Mar 5 | Mar 9 | Mar 13 | Mar 16 | Mar 20 | Mar 23 | Mar 30 |
| 16°F | Feb 12 | Feb 18 | Feb 24 | Feb 28 | Mar 3 | Mar 5 | Mar 10 | Mar 14 | Mar 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 29 | Oct 4 | Oct 8 | Oct 11 | Oct 14 | Oct 16 | Oct 19 | Oct 21 | Oct 25 |
| 32°F | Oct 9 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 28°F | Oct 20 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 18 |
| 24°F | Oct 31 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 26 | Dec 2 |
| 20°F | Nov 6 | Nov 11 | Nov 16 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 13 |
| 16°F | Nov 15 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 18 | Dec 24 |
Freeze probabilities 1991–2020 at Warrenton 1 N, MO, 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 63390 →Compare Wright City with another place →
Weather by month in Wright City
July is the warmest month at Warrenton 1 N, MO, averaging 88°F by day and 66°F at night; January is the coldest at 39°F and 20°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 88% of years and May still brings one in 14% of years.
Warmth for growing adds up to 3,915 growing degree days a year (base 50°F), fewer than at 65% of the 158 Missouri stations. 37% of them (1,434) have built up by the end of June, and July adds the most, 840.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 39 | 20 | 100% | 27 | 5 |
| Feb | 44 | 23 | 100% | 23 | 13 |
| Mar | 55 | 33 | 100% | 16 | 71 |
| Apr | 66 | 43 | 88% | 4 | 209 |
| May | 75 | 53 | 14% | <1 | 439 |
| Jun | 84 | 63 | 0% | 0 | 697 |
| Jul | 88 | 66 | 0% | 0 | 840 |
| Aug | 87 | 65 | 0% | 0 | 790 |
| Sep | 80 | 56 | 4% | 0 | 539 |
| Oct | 68 | 45 | 79% | 3 | 241 |
| Nov | 55 | 34 | 100% | 14 | 62 |
| Dec | 43 | 25 | 100% | 24 | 8 |
Monthly normals 1991–2020 at Warrenton 1 N, MO (827 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Washington, MO, 18 miles south of Wright City and 340 feet lower, has a last frost 6 days earlier (April 8), a first frost 2 days later (October 25), a season 8 days longer.
When it snows in Wright City, Missouri
The first measurable snow (0.1 inch or more) in Wright City usually arrives around December 29, and the last of the season around February 24. Those are the middle dates across the winters of 1991–2020 at Warrenton 1 N, MO, 6.2 miles away: half of years saw snow earlier, half later. Snow fell in 96% of those winters. The last 32°F night of spring typically comes 49 days after the last snow.
Planting calendar for 63390
| When | What to do |
|---|---|
| February 3 – February 17 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 17 – March 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 17 – March 31 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 14 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 31 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 9 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 23 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 63390 is 6 miles from Warrenton 1 N, MO, which stands at 827 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 63379 (Troy). The 2023 USDA Plant Hardiness Zone Map lists ZIP 63390 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°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.