USDA Hardiness Zone 6b
Frost Dates for 66048 — Leavenworth, Kansas
NOAA 1991–2020 normals from Leavenworth 3SW, KS (871 ft), 1 miles southwest.
Updated
In Leavenworth, the last spring frost (32°F) is around April 19 in half of years and has passed by May 4 in nine years out of ten. The first fall frost comes around October 19, as early as October 2 one year in ten, leaving a typical freeze-free season of 181 days (NOAA, Leavenworth 3SW, KS).
- Last spring frost
- April 19
- First fall frost
- October 19
- Growing season
- 181 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
- November 30
- Last snow
- March 9
- Winters with snow
- 100%
- Snow per year
- 18.8"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Leavenworth
Half of springs at Leavenworth 3SW, KS see their last 32°F night by April 19; only one in ten is past it by April 5, and one in ten still has one after May 4. Planting tender crops after April 26 leaves a 30% risk of a frost on them, after April 30 20%, and after May 4 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 57% of the 110 Kansas stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 19 in half of years, as early as October 2 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 8 days later, around October 27; in spring the one-in-ten date for 28°F is April 23, 11 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, shorter than at 69% of the 110 Kansas stations; it reaches 200 days one year in ten and falls short of 160 one year in ten. On average 137 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 11 days longer, to about April 30, and return around October 8. Severe cold of 16°F or below comes every winter, usually between November 25 and March 9.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 16 | Apr 20 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 6 | May 8 | May 13 |
| 32°F | Apr 5 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 26 | Apr 30 | May 4 |
| 28°F | Mar 25 | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 11 | Apr 14 | Apr 18 | Apr 23 |
| 24°F | Mar 12 | Mar 17 | Mar 21 | Mar 25 | Mar 30 | Apr 1 | Apr 5 | Apr 9 | Apr 14 |
| 20°F | Feb 28 | Mar 6 | Mar 11 | Mar 15 | Mar 18 | Mar 22 | Mar 25 | Mar 31 | Apr 4 |
| 16°F | Feb 20 | Feb 26 | Mar 2 | Mar 5 | Mar 9 | Mar 12 | Mar 15 | Mar 19 | Mar 26 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 29 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 14 | Oct 17 | Oct 22 |
| 32°F | Oct 2 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 21 | Oct 23 | Oct 26 | Oct 30 |
| 28°F | Oct 15 | Oct 19 | Oct 23 | Oct 25 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 24°F | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 21 |
| 20°F | Nov 1 | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 22 | Nov 27 | Dec 3 |
| 16°F | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 6 | Dec 12 |
Freeze probabilities 1991–2020 at Leavenworth 3SW, KS, 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 66048 →Compare Leavenworth with another place →
Compared with the next station
The nearest other station, Leavenworth, KS, 2 miles northeast of Leavenworth, has a last frost 7 days earlier (April 12), a first frost 8 days later (October 27), a season 15 days longer.
When it snows in Leavenworth, Kansas
The first measurable snow (0.1 inch or more) in Leavenworth usually arrives around November 30, and the last of the season around March 9. Those are the middle dates across the winters of 1991–2020 at Leavenworth, KS, 2.1 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 41 days after the last snow.
Planting calendar for 66048
| When | What to do |
|---|---|
| February 8 – February 22 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 22 – March 8 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 22 – April 5 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 19 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 27 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 5 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 19 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 66048 is 1 mile from Leavenworth 3SW, KS, which stands at 871 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 66048 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.