Photo: Farragutful · CC BY-SA 3.0Nights turn raw in Blue Grass each January, colder than in 88% of U.S. towns
High summer brings afternoon highs near 84°. From frosty January to warm July, readings climb 70°. By precipitation alone, it ranks drier than 69% of U.S. towns. Plan time outside from May to October, when highs sit at 63–84°.
A year in Blue Grass at a glance
Each month’s typical high and low, and what it brings.
What stands out about Blue Grass’ climate
Compared with towns across the U.S., with Blue Grass’ place in Iowa beside it.
What a year in Blue Grass feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 184 frost-free days a year
In half of years the last 32° night comes by April 19 and the first by October 22. Frost and day counts come from NOAA’s station at Rock Island L&d 15, IL, 11 miles from the town’s center, 220 ft lower.
The 2023 USDA map puts Blue Grass’ 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 29 inches of snow a winter
Snow, measured at Muscatine 2n, IA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 38 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 113 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Blue Grass
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 Rock Island L&d 15, IL.
Living with Blue Grass’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
184 frost-free days in zone 5b. The last frost comes by Apr 19 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 22.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Blue Grass from natural hazards, river flooding is the largest share (53%); heat waves, cold waves, winter storms and ice storms together are 13%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Blue Grass and similar climates
TownRatings has no climate map of the towns around Blue Grass yet.
Climates most like Blue Grass’, 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 |
|---|---|---|---|---|
| Blue Grass, IA | 14° | 84° | 38" | 29" |
| Mount Prospect, IL | 16° | 84° | 38" | 34" |
| Lowell, IN | 17° | 84° | 40" | 30" |
| Sayre, PA | 17° | 84° | 37" | 35" |
| 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 Blue Grass averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.0°).
A smaller shift than in 79% 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 Blue Grass compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Blue Grass’ place among Iowa’s.
Blue Grass weather by month
Highs, lows and precipitation from NOAA’s grid at Blue Grass’ center; snow, wet days and snow on the ground from Muscatine 2n, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 30° | 14° | 1.4" | 7.0" | 7 | 15 | 13° – 34° |
| February | 34° | 18° | 1.7" | 8.6" | 9 | 15 | 13° – 37° |
| March | 48° | 29° | 2.4" | 4.0" | 9 | 4 | 30° – 53° |
| April | 61° | 39° | 3.7" | 0.7" | 11 | 0 | 42° – 57° |
| May | 72° | 51° | 4.8" | 0.0" | 13 | 0 | 56° – 69° |
| June | 81° | 61° | 5.1" | 0.0" | 12 | 0 | 68° – 75° |
| July | 84° | 64° | 4.1" | 0.0" | 9 | 0 | 68° – 80° |
| August | 82° | 62° | 4.1" | 0.0" | 9 | 0 | 67° – 77° |
| September | 76° | 54° | 3.6" | 0.0" | 8 | 0 | 60° – 70° |
| October | 63° | 42° | 2.8" | 0.3" | 10 | 0 | 48° – 58° |
| November | 48° | 30° | 2.3" | 1.4" | 7 | 1 | 31° – 49° |
| December | 35° | 20° | 1.9" | 7.4" | 9 | 10 | 13° – 37° |
| Year | 59° | 40° | 37.7" | 29.4" | 113 | 46 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 13° to 37°. June is the most reliable, staying within 7°.
Where Blue Grass’ 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 Blue Grass’ center.
- Snow: Muscatine 2n, IA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rock Island L&d 15, IL, 11 miles from the town’s center, 220 ft lower; 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 Blue Grass’ climate
What is the weather like in Blue Grass?
A typical July afternoon reaches 84°, a January night drops to 14°, and about 29 inches of snow falls in a normal winter. Colder January nights than 88% of U.S. towns; cooler July afternoons than 60% of U.S. towns.
How cold does it get in Blue Grass in winter?
January nights average 14°. About 118 nights a year reach 32° or below and 7 reach 0° or below. In the coldest January of the last 30 years the month averaged 13°.
How much snow does Blue Grass get?
About 29 inches in a normal winter at Muscatine 2n, IA, most of it in February, with snow on the ground about 46 days a year.
How hot does it get in Blue Grass?
July, with a typical high of 84° and a low of 64°. About 18 days a year reach 90° (Rock Island L&d 15, IL).
When is the first and last frost in Blue Grass?
In half of years the last spring frost (32°) comes by April 19 and the first fall frost by October 22, about 184 frost-free days, at Rock Island L&d 15, IL.
What growing zone is Blue Grass 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 Blue Grass?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Blue Grass getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 79% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Blue Grass.
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.