USDA Hardiness Zone 5b
Frost Dates for 47959 — Monon, Indiana
NOAA 1991–2020 normals from Francesville, IN (680 ft), 9 miles north.
Updated
In Monon, the last spring frost (32°F) is around April 26 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 17, as early as October 2 one year in ten, leaving a typical freeze-free season of 173 days (NOAA, Francesville, IN).
- Last spring frost
- April 26
- First fall frost
- October 17
- Growing season
- 173 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- December 5
- Last snow
- March 15
- Winters with snow
- 100%
- Snow per year
- 26.3"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Monon
Half of springs at Francesville, IN see their last 32°F night by April 26; only one in ten is past it by April 12, and one in ten still has one after May 12. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 6 20%, and after May 12 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 35% of the 125 Indiana stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 17 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 11 days later, around October 28; in spring the one-in-ten date for 28°F is May 1, 11 days before the 32°F one. The freeze-free season lasts 173 days in a typical year, shorter than at 77% of the 125 Indiana stations; it reaches 192 days one year in ten and falls short of 152 one year in ten. On average 134 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 May 6, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 28 and March 13.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 28 | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 16 | May 22 |
| 32°F | Apr 12 | Apr 17 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 2 | May 6 | May 12 |
| 28°F | Apr 1 | Apr 5 | Apr 8 | Apr 12 | Apr 16 | Apr 18 | Apr 22 | Apr 24 | May 1 |
| 24°F | Mar 19 | Mar 25 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 14 | Apr 19 |
| 20°F | Mar 6 | Mar 12 | Mar 16 | Mar 21 | Mar 24 | Mar 28 | Mar 31 | Apr 2 | Apr 6 |
| 16°F | Feb 24 | Mar 2 | Mar 7 | Mar 10 | Mar 13 | Mar 16 | Mar 19 | Mar 24 | Mar 29 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 27 | Sep 30 | Oct 3 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 19 |
| 32°F | Oct 2 | Oct 8 | Oct 12 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 30 |
| 28°F | Oct 14 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 24°F | Oct 25 | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 23 |
| 20°F | Nov 4 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 26 | Dec 1 | Dec 7 |
| 16°F | Nov 10 | Nov 16 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 6 | Dec 11 | Dec 18 |
Freeze probabilities 1991–2020 at Francesville, IN, 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 47959 →Compare Monon with another place →
Weather by month in Monon
July is the warmest month at Francesville, IN, averaging 83°F by day and 62°F at night; January is the coldest at 32°F and 16°F. A freezing night is all but certain in every month from October 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 35% of years.
Warmth for growing adds up to 3,048 growing degree days a year (base 50°F), fewer than at 85% of the 125 Indiana stations. 35% of them (1,076) have built up by the end of June, and July adds the most, 701. Precipitation totals 38.9 inches a year, most in July (4.9") and least in February (2.0"); May to September bring 53% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 32 | 16 | 2.3 | 100% | 28 | 1 |
| Feb | 36 | 18 | 2.0 | 100% | 26 | 2 |
| Mar | 47 | 28 | 2.5 | 100% | 22 | 26 |
| Apr | 60 | 38 | 3.7 | 99% | 9 | 111 |
| May | 72 | 50 | 3.9 | 35% | <1 | 344 |
| Jun | 80 | 59 | 4.3 | 0% | 0 | 593 |
| Jul | 83 | 62 | 4.9 | 0% | 0 | 701 |
| Aug | 81 | 60 | 4.2 | 0% | 0 | 646 |
| Sep | 77 | 53 | 3.2 | 8% | 0 | 439 |
| Oct | 64 | 41 | 3.1 | 92% | 5 | 159 |
| Nov | 49 | 31 | 2.6 | 100% | 17 | 23 |
| Dec | 37 | 22 | 2.2 | 100% | 27 | 4 |
Monthly normals 1991–2020 at Francesville, IN (680 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, Chalmers 5 W, IN, 14 miles south of Monon, has a last frost 1 day earlier (April 25), the same first-frost date.
When it snows in Monon, Indiana
The first measurable snow (0.1 inch or more) in Monon usually arrives around December 5, and the last of the season around March 15. Those are the middle dates across the winters of 1991–2020 at Francesville, IN, 8.5 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 42 days after the last snow.
Planting calendar for 47959
| When | What to do |
|---|---|
| February 15 – March 1 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 1 – March 15 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 29 – April 12 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 26 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 25 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 3 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 17 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 47959 is 9 miles from Francesville, IN, which stands at 680 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 47959 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°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.