Photo: Jason McLaren · CC BY-SA 4.0Midwinter lows in Osceola sink below those of 89% of U.S. towns
Midsummer highs settle at about 85°. Expect the heaviest rain or snow in May and the lightest in January. By precipitation alone, it ranks drier than 70% of U.S. towns. Warm coats and heating bills mark the months from November to March, when means dip under 50°.
A year in Osceola at a glance
Each month’s typical high and low, and what it brings.
What stands out about Osceola’s climate
Compared with towns across the U.S., with Osceola’s place in Iowa beside it.
What a year in Osceola feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 162 frost-free days a year
In half of years the last 32° night comes by April 29 and the first by October 9. Frost and day counts come from NOAA’s station at Osceola, IA, 2.2 miles from the town’s center, at about the same height.
The 2023 USDA map puts Osceola’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 28 inches of snow a winter
Snow, measured at Osceola, IA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 37 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 98 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Osceola
87% 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 Osceola, IA.
Living with Osceola’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
162 frost-free days in zone 5b. The last frost comes by Apr 29 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 9.
Months with highs of 62–84° and lows of 40° or more: May, June, August, September and October. 2.2 miles of trails are waiting.
Parks & trails →Cold waves are 29% of the yearly building losses FEMA expects in Osceola from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Osceola and similar climates
TownRatings has no climate map of the towns around Osceola yet.
Climates most like Osceola’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 |
|---|---|---|---|---|
| Osceola, IA | 13° | 85° | 37" | 28" |
| Colona, IL | 15° | 85° | 37" | 28" |
| Lowell, IN | 17° | 84° | 40" | 30" |
| Beloit, WI | 13° | 83° | 37" | 37" |
| Bryan, OH | 18° | 84° | 37" | 29" |
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 Osceola averaged 0.6° warmer than the 1900s. The biggest change is in December (+2.3°).
A smaller shift than in 97% 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 Osceola compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Osceola’s place among Iowa’s.
Osceola weather by month
Highs, lows and precipitation from NOAA’s grid at Osceola’s center; snow, wet days and snow on the ground from Osceola, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 13° | 1.0" | 8.2" | 5 | 16 | 15° – 35° |
| February | 37° | 18° | 1.3" | 7.2" | 6 | 14 | 17° – 38° |
| March | 49° | 28° | 2.2" | 3.1" | 8 | 4 | 32° – 53° |
| April | 62° | 39° | 4.0" | 1.1" | 10 | 0 | 42° – 57° |
| May | 72° | 50° | 5.4" | 0.2" | 13 | 0 | 55° – 69° |
| June | 81° | 60° | 5.1" | 0.0" | 11 | 0 | 67° – 75° |
| July | 85° | 64° | 4.2" | 0.0" | 9 | 0 | 69° – 81° |
| August | 84° | 62° | 4.2" | 0.0" | 9 | 0 | 66° – 77° |
| September | 77° | 53° | 3.8" | 0.0" | 8 | 0 | 58° – 71° |
| October | 64° | 41° | 2.8" | 0.5" | 8 | 0 | 46° – 58° |
| November | 49° | 29° | 2.1" | 2.1" | 6 | 2 | 30° – 49° |
| December | 37° | 19° | 1.4" | 5.7" | 6 | 9 | 12° – 35° |
| Year | 61° | 40° | 37.4" | 28.1" | 98 | 46 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 12° to 35°. June is the most reliable, staying within 8°.
Where Osceola’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 Osceola’s center.
- Snow: Osceola, IA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Osceola, IA, 2.2 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 Osceola’s climate
What is the weather like in Osceola?
A typical July afternoon reaches 85°, a January night drops to 13°, and about 28 inches of snow falls in a normal winter. Colder January nights than 89% of U.S. towns; hotter July afternoons than 51% of U.S. towns.
How cold does it get in Osceola in winter?
January nights average 13°. About 149 nights a year reach 32° or below and 14 reach 0° or below. In the coldest January of the last 30 years the month averaged 15°.
How much snow does Osceola get?
About 28 inches in a normal winter at Osceola, IA, most of it in January, with snow on the ground about 46 days a year.
How hot does it get in Osceola?
July, with a typical high of 85° and a low of 64°. About 25 days a year reach 90° and 1 reach 100° (Osceola, IA).
When is the first and last frost in Osceola?
In half of years the last spring frost (32°) comes by April 29 and the first fall frost by October 9, about 162 frost-free days, at Osceola, IA.
What growing zone is Osceola 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 Osceola?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Osceola getting warmer?
Yes: 1991–2020 averaged 0.6° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 97% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Osceola.
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.