Dry weather: only 36 inches of rain and melted snow a year in Denison, less than in 74% of U.S. towns
The warmest part of a July day comes in at 89° on average. By January nights alone, it runs colder than 71% of U.S. towns. Since 1901–2000, the year has warmed by 0.9°, most of all in March. The frost-free window for a garden runs roughly April 24 to October 14.
A year in Denison at a glance
Each month’s typical high and low, and what it brings.
What stands out about Denison’s climate
Compared with towns across the U.S., with Denison’s place in Kansas beside it.
What a year in Denison feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 172 frost-free days a year
In half of years the last 32° night comes by April 24 and the first by October 14. Frost and day counts come from NOAA’s station at Holton, KS, 8 miles from the town’s center, at about the same height.
The 2023 USDA map puts Denison’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −7°. 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 14 inches of snow a winter
Snow, measured at Valley Falls 3 Sw, KS, falls mostly in February. 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 98 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Denison
83% of the work is heating. Months averaging under 55° run from November 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 Holton, KS.
Living with Denison’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
172 frost-free days in zone 6a. The last frost comes by Apr 24 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 14.
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 Denison from natural hazards, river flooding is the largest share (39%); heat waves, cold waves, winter storms and ice storms together are 16%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Denison and similar climates
TownRatings has no climate map of the towns around Denison yet.
Climates most like Denison’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 |
|---|---|---|---|---|
| Denison, KS | 18° | 89° | 36" | 14" |
| Hannibal, MO | 19° | 87° | 39" | 13" |
| Jacksonville, IL | 19° | 87° | 39" | 16" |
| Fort Madison, IA | 17° | 86° | 39" | 18" |
| Terre Haute, IN | 21° | 87° | 43" | 15" |
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 Denison averaged 0.9° warmer than the 1900s. The biggest change is in March (+2.1°).
A smaller shift than in 84% 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 Denison compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Denison’s place among Kansas’.
Denison weather by month
Highs, lows and precipitation from NOAA’s grid at Denison’s center; snow, wet days and snow on the ground from Valley Falls 3 Sw, KS. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 18° | 0.8" | 3.6" | 6 | 5 | 22° – 39° |
| February | 44° | 22° | 1.2" | 4.4" | 6 | 5 | 23° – 42° |
| March | 55° | 32° | 2.2" | 1.0" | 8 | 1 | 36° – 57° |
| April | 65° | 42° | 3.7" | 0.1" | 11 | 0 | 45° – 59° |
| May | 75° | 53° | 5.2" | 0.0" | 12 | 0 | 58° – 73° |
| June | 84° | 63° | 4.8" | 0.0" | 10 | 0 | 68° – 78° |
| July | 89° | 67° | 4.6" | 0.0" | 10 | 0 | 73° – 84° |
| August | 87° | 65° | 4.1" | 0.0" | 9 | 0 | 70° – 82° |
| September | 79° | 56° | 3.5" | 0.0" | 8 | 0 | 62° – 74° |
| October | 67° | 44° | 2.9" | 0.2" | 8 | 0 | 49° – 61° |
| November | 53° | 32° | 1.8" | 0.9" | 6 | 0 | 35° – 50° |
| December | 42° | 22° | 1.4" | 3.3" | 6 | 3 | 19° – 37° |
| Year | 65° | 43° | 36.1" | 13.5" | 98 | 15 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 36° to 57°. June is the most reliable, staying within 10°.
Where Denison’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 Denison’s center.
- Snow: Valley Falls 3 Sw, KS.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Holton, KS, 8 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 Denison’s climate
What is the weather like in Denison?
A typical July afternoon reaches 89°, a January night drops to 18°, and about 14 inches of snow falls in a normal winter. Colder January nights than 71% of U.S. towns; hotter July afternoons than 71% of U.S. towns.
How cold does it get in Denison in winter?
January nights average 18°. About 131 nights a year reach 32° or below and 6 reach 0° or below. In the coldest January of the last 30 years the month averaged 22°.
How much snow does Denison get?
About 14 inches in a normal winter at Valley Falls 3 Sw, KS, most of it in February, with snow on the ground about 15 days a year.
How hot does it get in Denison?
July, with a typical high of 89° and a low of 67°. About 38 days a year reach 90° and 4 reach 100° (Holton, KS).
When is the first and last frost in Denison?
In half of years the last spring frost (32°) comes by April 24 and the first fall frost by October 14, about 172 frost-free days, at Holton, KS.
What growing zone is Denison in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −7°.
What is the best time of year to visit Denison?
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 Denison getting warmer?
Yes: 1991–2020 averaged 0.9° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 84% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Denison.
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.