USDA Hardiness Zone 6b
Frost Dates for 66402 — Auburn, Kansas
NOAA 1991–2020 normals from Topeka Forbes Field, KS (1,067 ft), 10 miles east.
Updated
In Auburn, the last spring frost (32°F) is around April 15 in half of years and has passed by April 30 in nine years out of ten. The first fall frost comes around October 21, as early as October 5 one year in ten, leaving a typical freeze-free season of 185 days (NOAA, Topeka Forbes Field, KS).
- Last spring frost
- April 15
- First fall frost
- October 21
- Growing season
- 185 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 10
- Last snow
- March 2
- Winters with snow
- 95%
- Snow per year
- 12.3"
median, 1991–2020
median, 1991–2020
19 of 20 observed
NOAA normal
Frost risk by date in Auburn
Half of springs at Topeka Forbes Field, KS see their last 32°F night by April 15; only one in ten is past it by April 2, and one in ten still has one after April 30. Planting tender crops after April 21 leaves a 30% risk of a frost on them, after April 25 20%, and after April 30 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 21 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 October 31; in spring the one-in-ten date for 28°F is April 21, 9 days before the 32°F one. The freeze-free season lasts 185 days in a typical year, shorter than at 58% of the 110 Kansas stations; it reaches 204 days one year in ten and falls short of 164 one year in ten. On average 117 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 27, and return around October 11. Severe cold of 16°F or below comes every winter, usually between November 28 and March 5.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 12 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | Apr 29 | May 2 | May 6 | May 11 |
| 32°F | Apr 2 | Apr 6 | Apr 9 | Apr 12 | Apr 15 | Apr 19 | Apr 21 | Apr 25 | Apr 30 |
| 28°F | Mar 21 | Mar 26 | Mar 31 | Apr 3 | Apr 5 | Apr 8 | Apr 11 | Apr 16 | Apr 21 |
| 24°F | Mar 8 | Mar 15 | Mar 20 | Mar 23 | Mar 27 | Mar 30 | Apr 2 | Apr 5 | Apr 10 |
| 20°F | Feb 26 | Mar 3 | Mar 7 | Mar 12 | Mar 16 | Mar 19 | Mar 22 | Mar 26 | Apr 1 |
| 16°F | Feb 18 | Feb 23 | Feb 28 | Mar 2 | Mar 5 | Mar 8 | Mar 13 | Mar 17 | Mar 22 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 2 | Oct 5 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 25 |
| 32°F | Oct 5 | Oct 11 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 30 | Nov 2 |
| 28°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 24°F | Oct 26 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 19 | Nov 25 |
| 20°F | Nov 2 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 25 | Nov 29 | Dec 4 |
| 16°F | Nov 10 | Nov 16 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 9 | Dec 16 |
Freeze probabilities 1991–2020 at Topeka Forbes Field, 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 66402 →Compare Auburn with another place →
Weather by month in Auburn
July is the warmest month at Topeka Forbes Field, KS, averaging 91°F by day and 69°F at night; January is the coldest at 41°F and 19°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 10% of years.
Warmth for growing adds up to 4,183 growing degree days a year (base 50°F), more than at 61% of the 110 Kansas stations. 36% of them (1,523) have built up by the end of June, and July adds the most, 916. Precipitation totals 36.7 inches a year, most in May (5.2") and least in January (0.8"); May to September bring 61% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 41 | 19 | 0.8 | 100% | 28 | 2 |
| Feb | 46 | 23 | 1.2 | 100% | 23 | 13 |
| Mar | 57 | 33 | 2.3 | 99% | 16 | 79 |
| Apr | 67 | 43 | 3.9 | 92% | 5 | 209 |
| May | 76 | 54 | 5.2 | 10% | <1 | 470 |
| Jun | 86 | 64 | 4.7 | 0% | 0 | 750 |
| Jul | 91 | 69 | 4.6 | 0% | 0 | 916 |
| Aug | 90 | 66 | 4.5 | 0% | 0 | 863 |
| Sep | 81 | 57 | 3.5 | 4% | 0 | 568 |
| Oct | 69 | 45 | 2.8 | 84% | 4 | 254 |
| Nov | 55 | 33 | 1.8 | 100% | 15 | 53 |
| Dec | 44 | 23 | 1.4 | 100% | 27 | 6 |
Monthly normals 1991–2020 at Topeka Forbes Field, KS (1,067 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, Topeka - NWS, KS, 16 miles northeast of Auburn and 187 feet lower, has a last frost 1 day later (April 16), a first frost 1 day later (October 22), a season 4 days longer.
When it snows in Auburn, Kansas
The first measurable snow (0.1 inch or more) in Auburn usually arrives around December 10, and the last of the season around March 2. Those are the middle dates across the winters of 1991–2020 at Auburn, KS, 1.7 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 44 days after the last snow.
Planting calendar for 66402
| When | What to do |
|---|---|
| February 4 – February 18 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 18 – March 4 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 18 – April 1 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 15 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 21 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 66402 is 10 miles from Topeka Forbes Field, KS, which stands at 1,067 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 66614 (Topeka). The 2023 USDA Plant Hardiness Zone Map lists ZIP 66402 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.