Mill Spring’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 90°, a January night drops to 24°, and about 9 inches of snow falls in a normal winter.
A year in Mill Spring at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mill Spring’s climate
Compared with towns across the U.S., with Mill Spring’s place in Missouri beside it.
What a year in Mill Spring feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 199 frost-free days a year
In half of years the last 32° night comes by April 9 and the first by October 26. Frost and day counts come from NOAA’s station at Clearwater Dam, MO, 7 miles from the town’s center, 120 ft higher.
The 2023 USDA map puts Mill Spring’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 1°. 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 9 inches of snow a winter
Snow, measured at Williamsville, MO, is heaviest from January through February, about 3 inches a month. Precipitation (rain plus melted snow) adds up to 49 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 107 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Mill Spring
76% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Clearwater Dam, MO.
Living with Mill Spring’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
199 frost-free days in zone 7a. The last frost comes by Apr 9 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 26.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Mill Spring from natural hazards, river flooding is the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 27%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mill Spring and similar climates
TownRatings has no climate map of the towns around Mill Spring yet.
Climates most like Mill Spring’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 |
|---|---|---|---|---|
| Mill Spring, MO | 24° | 90° | 49" | 8.9" |
| Cave Springs, AR | 26° | 90° | 47" | 9.5" |
| Pittsburg, KS | 24° | 90° | 46" | 9.5" |
| Evansville, IN | 25° | 88° | 48" | 11" |
| Mount Carmel, IL | 24° | 88° | 48" | 8.9" |
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 Mill Spring averaged 0.7° warmer than the 1900s. The biggest change is in February (+1.6°).
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 Mill Spring compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mill Spring’s place among Missouri’s.
Mill Spring weather by month
Highs, lows and precipitation from NOAA’s grid at Mill Spring’s center; snow, wet days and snow on the ground from Williamsville, MO. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 44° | 24° | 3.2" | 2.7" | 9 | 3 | 28° – 42° |
| February | 50° | 28° | 3.3" | 2.5" | 9 | 3 | 29° – 47° |
| March | 59° | 35° | 4.5" | 1.6" | 10 | 1 | 40° – 59° |
| April | 70° | 44° | 5.4" | 0.0" | 10 | 0 | 50° – 64° |
| May | 78° | 54° | 5.5" | 0.0" | 12 | 0 | 61° – 73° |
| June | 86° | 63° | 3.8" | 0.0" | 9 | 0 | 70° – 79° |
| July | 90° | 67° | 4.0" | 0.0" | 9 | 0 | 73° – 83° |
| August | 88° | 64° | 3.7" | 0.0" | 8 | 0 | 71° – 83° |
| September | 82° | 57° | 3.6" | 0.0" | 7 | 0 | 65° – 76° |
| October | 71° | 45° | 3.5" | 0.1" | 8 | 0 | 54° – 63° |
| November | 58° | 35° | 4.7" | 0.1" | 9 | 0 | 39° – 52° |
| December | 47° | 27° | 3.5" | 1.9" | 9 | 3 | 25° – 44° |
| Year | 69° | 45° | 48.5" | 8.9" | 107 | 9 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 25° to 44°. October is the most reliable, staying within 10°.
Where Mill Spring’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 Mill Spring’s center.
- Snow: Williamsville, MO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Clearwater Dam, MO, 7 miles from the town’s center, 120 ft higher; 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 Mill Spring’s climate
What is the weather like in Mill Spring?
A typical July afternoon reaches 90°, a January night drops to 24°, and about 9 inches of snow falls in a normal winter. Milder January nights than 60% of U.S. towns; hotter July afternoons than 75% of U.S. towns.
How cold does it get in Mill Spring in winter?
January nights average 24°. About 109 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 28°.
How much snow does Mill Spring get?
About 8.9 inches in a normal winter at Williamsville, MO, heaviest from January through February, about 3 inches a month, with snow on the ground about 9 days a year.
How hot does it get in Mill Spring?
July, with a typical high of 90° and a low of 67°. About 50 days a year reach 90° and 3 reach 100° (Clearwater Dam, MO).
When is the first and last frost in Mill Spring?
In half of years the last spring frost (32°) comes by April 9 and the first fall frost by October 26, about 199 frost-free days, at Clearwater Dam, MO.
What growing zone is Mill Spring in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 1°.
What is the best time of year to visit Mill Spring?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Mill Spring 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 Mill Spring.
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.