Winter nights in Altamont are colder than in 72% of U.S. towns
Sunny July days climb to about 87°. Its July heat outdoes that of 62% of U.S. towns. Compared with 1901–2000, the average now sits 0.8° higher. Keep the boiler serviced for the months from November to March, which average under 50°.
A year in Altamont at a glance
Each month’s typical high and low, and what it brings.
What stands out about Altamont’s climate
Compared with towns across the U.S., with Altamont’s place in Missouri beside it.
What a year in Altamont 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 21. Frost and day counts come from NOAA’s station at Gallatin 1w, MO, 6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Altamont’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −9°. 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 19 inches of snow a winter
Snow, measured at Pattonsburg 2s, MO, falls mostly in February. Precipitation (rain plus melted snow) adds up to 40 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 Altamont
85% 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 Gallatin 1w, MO.
Living with Altamont’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
184 frost-free days in zone 6a. 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 21.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Altamont from natural hazards, river flooding is the largest share (41%); heat waves, cold waves, winter storms and ice storms together are 22%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Altamont and its neighbors
Every town next door is within a degree of Altamont in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Altamont’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 |
|---|---|---|---|---|
| Altamont, MO | 18° | 87° | 40" | 19" |
| Fort Madison, IA | 17° | 86° | 39" | 18" |
| Jacksonville, IL | 19° | 87° | 39" | 16" |
| Terre Haute, IN | 21° | 87° | 43" | 15" |
| Lock Haven, PA | 19° | 86° | 41" | 30" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Altamont averaged 0.8° warmer than the 1900s. The biggest change is in December (+1.9°).
A smaller shift than in 92% 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 Altamont compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Altamont’s place among Missouri’s.
Altamont weather by month
Highs, lows and precipitation from NOAA’s grid at Altamont’s center; snow, wet days and snow on the ground from Pattonsburg 2s, MO. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 35° | 18° | 1.1" | 4.5" | 6 | 10 | 19° – 37° |
| February | 41° | 22° | 1.5" | 5.2" | 6 | 7 | 21° – 41° |
| March | 53° | 31° | 2.5" | 2.2" | 8 | 2 | 35° – 56° |
| April | 64° | 42° | 3.8" | 0.8" | 10 | 0 | 44° – 59° |
| May | 74° | 52° | 5.6" | 0.0" | 12 | 0 | 58° – 72° |
| June | 83° | 62° | 5.3" | 0.0" | 10 | 0 | 69° – 77° |
| July | 87° | 66° | 4.6" | 0.0" | 9 | 0 | 71° – 84° |
| August | 85° | 64° | 4.1" | 0.0" | 8 | 0 | 68° – 80° |
| September | 78° | 55° | 4.0" | 0.0" | 8 | 0 | 61° – 72° |
| October | 66° | 43° | 3.2" | 0.2" | 8 | 0 | 48° – 59° |
| November | 51° | 32° | 2.2" | 1.1" | 7 | 1 | 33° – 50° |
| December | 39° | 22° | 1.7" | 4.5" | 6 | 6 | 17° – 37° |
| Year | 63° | 42° | 39.5" | 18.5" | 98 | 26 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 35° to 56°. June is the most reliable, staying within 8°.
Where Altamont’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 Altamont’s center.
- Snow: Pattonsburg 2s, MO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Gallatin 1w, MO, 6 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 Altamont’s climate
What is the weather like in Altamont?
A typical July afternoon reaches 87°, a January night drops to 18°, and about 19 inches of snow falls in a normal winter. Colder January nights than 72% of U.S. towns; hotter July afternoons than 62% of U.S. towns.
How cold does it get in Altamont in winter?
January nights average 18°. About 127 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 19°.
How much snow does Altamont get?
About 19 inches in a normal winter at Pattonsburg 2s, MO, most of it in February, with snow on the ground about 26 days a year.
How hot does it get in Altamont?
July, with a typical high of 87° and a low of 66°. About 29 days a year reach 90° and 2 reach 100° (Gallatin 1w, MO).
When is the first and last frost in Altamont?
In half of years the last spring frost (32°) comes by April 19 and the first fall frost by October 21, about 184 frost-free days, at Gallatin 1w, MO.
What growing zone is Altamont in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −9°.
What is the best time of year to visit Altamont?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Altamont getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 92% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Altamont.
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.