Photo: C. A. Tucker · CC BY-SA 3.0Greenfield’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 85°, a January night drops to 12°, and about 26 inches of snow falls in a normal winter.
A year in Greenfield at a glance
Each month’s typical high and low, and what it brings.
What stands out about Greenfield’s climate
Compared with towns across the U.S., with Greenfield’s place in Iowa beside it.
What a year in Greenfield feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 170 frost-free days a year
In half of years the last 32° night comes by April 25 and the first by October 12. Frost and day counts come from NOAA’s station at Greenfield, IA, 1.1 miles from the town’s center, at about the same height.
The 2023 USDA map puts Greenfield’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −13°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 26 inches of snow a winter
Snow, measured at Greenfield, IA, is heaviest from January through February, about 7 inches a month. Precipitation (rain plus melted snow) adds up to 36 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 103 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Greenfield
88% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Greenfield, IA.
Living with Greenfield’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
170 frost-free days in zone 5b. The last frost comes by Apr 25 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 12.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September. 0.1 miles of trails are waiting.
Parks & trails →Cold waves are 51% of the yearly building losses FEMA expects in Greenfield from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Greenfield and similar climates
TownRatings has no climate map of the towns around Greenfield yet.
Climates most like Greenfield’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Greenfield, IA | 12° | 85° | 36" | 26" |
| Colona, IL | 15° | 85° | 37" | 28" |
| Prairie du Chien, WI | 10° | 83° | 37" | 34" |
| St. John, IN | 17° | 84° | 40" | 27" |
| Tecumseh, MI | 17° | 84° | 34" | 26" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Greenfield averaged 0.7° warmer than the 1900s. The biggest change is in December (+2.2°).
A smaller shift than in 94% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Greenfield compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Greenfield’s place among Iowa’s.
Greenfield weather by month
Highs, lows and precipitation from NOAA’s grid at Greenfield’s center; snow, wet days and snow on the ground from Greenfield, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 30° | 12° | 0.8" | 6.8" | 6 | 17 | 14° – 34° |
| February | 35° | 16° | 1.2" | 7.3" | 7 | 16 | 16° – 36° |
| March | 49° | 27° | 2.0" | 3.0" | 8 | 6 | 31° – 53° |
| April | 61° | 37° | 3.6" | 0.8" | 11 | 1 | 41° – 56° |
| May | 71° | 49° | 5.4" | 0.1" | 13 | 0 | 55° – 68° |
| June | 81° | 59° | 5.3" | 0.0" | 11 | 0 | 67° – 74° |
| July | 85° | 63° | 4.0" | 0.0" | 9 | 0 | 68° – 81° |
| August | 83° | 61° | 4.5" | 0.0" | 9 | 0 | 66° – 76° |
| September | 76° | 52° | 3.7" | 0.0" | 8 | 0 | 58° – 70° |
| October | 63° | 39° | 2.9" | 0.4" | 9 | 0 | 44° – 56° |
| November | 48° | 28° | 1.8" | 1.7" | 6 | 2 | 28° – 48° |
| December | 35° | 17° | 1.3" | 5.4" | 7 | 11 | 10° – 34° |
| Year | 60° | 38° | 36.4" | 25.5" | 103 | 52 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 10° to 34°. June is the most reliable, staying within 7°.
Where Greenfield’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Greenfield’s center.
- Snow: Greenfield, IA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Greenfield, IA, 1.1 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Greenfield’s climate
What is the weather like in Greenfield?
A typical July afternoon reaches 85°, a January night drops to 12°, and about 26 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; cooler July afternoons than 55% of U.S. towns.
How cold does it get in Greenfield in winter?
January nights average 12°. About 138 nights a year reach 32° or below and 13 reach 0° or below. In the coldest January of the last 30 years the month averaged 14°.
How much snow does Greenfield get?
About 26 inches in a normal winter at Greenfield, IA, heaviest from January through February, about 7 inches a month, with snow on the ground about 52 days a year.
How hot does it get in Greenfield?
July, with a typical high of 85° and a low of 63°. About 19 days a year reach 90° (Greenfield, IA).
When is the first and last frost in Greenfield?
In half of years the last spring frost (32°) comes by April 25 and the first fall frost by October 12, about 170 frost-free days, at Greenfield, IA.
What growing zone is Greenfield in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −13°.
What is the best time of year to visit Greenfield?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Greenfield getting warmer?
Yes: 1991–2020 averaged 0.7° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 94% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Greenfield.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.