USDA Hardiness Zone 6a
Frost Dates for 66434 — Hiawatha, Kansas
NOAA 1991–2020 normals from Hiawatha 1 S, KS (1,061 ft), 2 miles southeast.
Updated
In Hiawatha, the last spring frost (32°F) is around April 14 in half of years and has passed by April 28 in nine years out of ten. The first fall frost comes around October 22, as early as October 5 one year in ten, leaving a typical freeze-free season of 188 days (NOAA, Hiawatha 1 S, KS).
- Last spring frost
- April 14
- First fall frost
- October 22
- Growing season
- 188 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- December 3
- Last snow
- March 14
- Winters with snow
- 100%
- Snow per year
- 16.9"
median, 1991–2020
median, 1991–2020
25 of 25 observed
NOAA normal
Frost risk by date in Hiawatha
Half of springs at Hiawatha 1 S, KS see their last 32°F night by April 14; only one in ten is past it by April 1, and one in ten still has one after April 28. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 23 20%, and after April 28 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 44% of the 110 Kansas stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 22 in half of years, as early as October 5 one year in ten, and holds off past November 2 one year in ten. A hard freeze of 28°F follows 10 days later, around November 1; in spring the one-in-ten date for 28°F is April 19, 9 days before the 32°F one. The freeze-free season lasts 188 days in a typical year, shorter than at 48% of the 110 Kansas stations; it reaches 207 days one year in ten and falls short of 168 one year in ten. On average 132 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 10 days longer, to about April 24, and return around October 10. Severe cold of 16°F or below comes every winter, usually between November 29 and March 6.
| 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 3 | May 7 |
| 32°F | Apr 1 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 16 | Apr 20 | Apr 23 | Apr 28 |
| 28°F | Mar 20 | Mar 27 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 19 |
| 24°F | Mar 7 | Mar 14 | Mar 19 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 4 | Apr 10 |
| 20°F | Feb 28 | Mar 5 | Mar 9 | Mar 13 | Mar 16 | Mar 20 | Mar 23 | Mar 28 | Apr 1 |
| 16°F | Feb 18 | Feb 25 | Feb 28 | Mar 3 | Mar 6 | Mar 10 | Mar 14 | Mar 18 | Mar 23 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 30 | Oct 3 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 24 |
| 32°F | Oct 5 | Oct 12 | Oct 16 | Oct 20 | Oct 22 | Oct 24 | Oct 27 | Oct 30 | Nov 2 |
| 28°F | Oct 18 | Oct 23 | Oct 25 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 24°F | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 20 | Nov 26 |
| 20°F | Nov 4 | Nov 8 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 6 |
| 16°F | Nov 12 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 1 | Dec 5 | Dec 11 | Dec 19 |
Freeze probabilities 1991–2020 at Hiawatha 1 S, 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 66434 →Compare Hiawatha with another place →
Compared with the next station
The nearest other station, Horton, KS, 13 miles south of Hiawatha, has a last frost 4 days later (April 18), a first frost 5 days earlier (October 17), a season 8 days shorter.
When it snows in Hiawatha, Kansas
The first measurable snow (0.1 inch or more) in Hiawatha usually arrives around December 3, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Hiawatha 1 S, KS, 1.6 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 31 days after the last snow.
Planting calendar for 66434
| 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 30 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 8 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 22 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 66434 is 2 miles from Hiawatha 1 S, KS, which stands at 1,061 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 66434 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°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.