USDA Hardiness Zone 5a
Frost Dates for 52068 — Peosta, Iowa
NOAA 1991–2020 normals from Dubuque Regional Airport, IA (1,056 ft), 6 miles east.
Updated
In Peosta, the last spring frost (32°F) is around April 28 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 11, as early as September 28 one year in ten, leaving a typical freeze-free season of 165 days (NOAA, Dubuque Regional Airport, IA).
- Last spring frost
- April 28
- First fall frost
- October 11
- Growing season
- 165 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 12
- Last snow
- April 10
- Winters with snow
- 100%
- Snow per year
- 42.5"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Peosta
Half of springs at Dubuque Regional Airport, IA see their last 32°F night by April 28; only one in ten is past it by April 13, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 14 days between the even-odds date and the one-in-ten date is wider than at 58% of the 132 Iowa stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 11 in half of years, as early as September 28 one year in ten, and holds off past October 23 one year in ten. A hard freeze of 28°F follows 10 days later, around October 21; in spring the one-in-ten date for 28°F is May 3, 9 days before the 32°F one. The freeze-free season lasts 165 days in a typical year, shorter than at 45% of the 132 Iowa stations; it reaches 186 days one year in ten and falls short of 146 one year in ten. On average 144 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 9 days longer, to about May 7, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 19 and March 17.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 29 | May 2 | May 5 | May 7 | May 10 | May 13 | May 16 | May 21 |
| 32°F | Apr 13 | Apr 18 | Apr 21 | Apr 25 | Apr 28 | May 1 | May 4 | May 7 | May 12 |
| 28°F | Apr 2 | Apr 7 | Apr 10 | Apr 14 | Apr 17 | Apr 20 | Apr 24 | Apr 29 | May 3 |
| 24°F | Mar 21 | Mar 29 | Apr 1 | Apr 4 | Apr 6 | Apr 9 | Apr 12 | Apr 17 | Apr 22 |
| 20°F | Mar 11 | Mar 16 | Mar 20 | Mar 25 | Mar 28 | Apr 1 | Apr 3 | Apr 7 | Apr 12 |
| 16°F | Mar 3 | Mar 7 | Mar 11 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 29 | Apr 3 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 24 | Sep 27 | Sep 29 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 14 |
| 32°F | Sep 28 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 23 |
| 28°F | Oct 8 | Oct 13 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 30 | Nov 2 |
| 24°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 8 | Nov 13 |
| 20°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 25 |
| 16°F | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 30 | Dec 6 |
Freeze probabilities 1991–2020 at Dubuque Regional Airport, IA, 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 52068 →Compare Peosta with another place →
Weather by month in Peosta
July is the warmest month at Dubuque Regional Airport, IA, averaging 82°F by day and 62°F at night; January is the coldest at 27°F and 11°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 42% of years.
Warmth for growing adds up to 2,745 growing degree days a year (base 50°F), fewer than at 83% of the 132 Iowa stations. 34% of them (947) have built up by the end of June, and July adds the most, 674. Precipitation totals 38.3 inches a year, most in June (5.2") and least in January (1.3"); May to September bring 58% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 27 | 11 | 1.3 | 100% | 30 | 0 |
| Feb | 31 | 15 | 1.6 | 100% | 26 | 1 |
| Mar | 44 | 26 | 2.3 | 100% | 23 | 18 |
| Apr | 58 | 37 | 4.1 | 99% | 8 | 78 |
| May | 69 | 49 | 4.3 | 42% | 1 | 294 |
| Jun | 79 | 59 | 5.2 | 0% | 0 | 556 |
| Jul | 82 | 62 | 4.8 | 0% | 0 | 674 |
| Aug | 80 | 60 | 4.0 | 0% | 0 | 614 |
| Sep | 73 | 52 | 3.8 | 17% | <1 | 378 |
| Oct | 60 | 40 | 2.9 | 98% | 7 | 117 |
| Nov | 45 | 28 | 2.2 | 100% | 20 | 14 |
| Dec | 32 | 17 | 1.8 | 100% | 29 | 1 |
Monthly normals 1991–2020 at Dubuque Regional Airport, IA (1,056 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, Dubuque L&D 11, IA, 11 miles northeast of Peosta and 436 feet lower, has a last frost 9 days earlier (April 19), a first frost 10 days later (October 21), a season 19 days longer.
When it snows in Peosta, Iowa
The first measurable snow (0.1 inch or more) in Peosta usually arrives around November 12, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Dubuque Regional Airport, IA, 6.2 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 18 days after the last snow.
Planting calendar for 52068
| When | What to do |
|---|---|
| February 17 – March 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 3 – March 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 31 – April 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 19 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 11 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 52068 is 6 miles from Dubuque Regional Airport, IA, which stands at 1,056 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 52003 (Dubuque). The 2023 USDA Plant Hardiness Zone Map lists ZIP 52068 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°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.