Alton, Kansas climate: Normal weather by month, frost dates and records
Alton's normal year runs from 14°F January nights to 93°F July afternoons, with 28.6 inches of precipitation and 18 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.8°C, January lows of −10°C, July highs of 34°C, 726 mm of precipitation a year.
- NOAA stationAlton (1 mi W)
- Station IDUSC00140201
- Location39.48°N 98.97°W
- Elevation1,685 ft (514 m)
- From the center1 miles
- Population93
On October 23, the normal high in Alton is 67°F and the normal low 36°F, and the chance of measurable rain or snow is 19%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Alton.
- Jan 42° 14°
- Feb 46° 18°
- Mar 57° 27°
- Apr 67° 36°
- May 76° 48°
- Jun 88° 60°
- Jul 93° 65°
- Aug 91° 63°
- Sep 83° 53°
- Oct 70° 39°
- Nov 56° 26°
- Dec 44° 18°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Alton each month?
July is the warmest month, with normal highs of 93°F; January the coldest, with normal lows of 14°F. The most precipitation falls in July (4.92 in), the least in January (0.67 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 42°F | 14°F | 28.0°F | 0.67 | 3.8 | 4 | <1 | 31 | 9 h 40 min |
| February | 46°F | 18°F | 31.9°F | 0.69 | 4.8 | 5 | <1 | 26 | 10 h 40 min |
| March | 57°F | 27°F | 41.9°F | 1.55 | 2.0 | 6 | <1 | 23 | 11 h 50 min |
| April | 67°F | 36°F | 51.4°F | 2.30 | 1.2 | 8 | 1 | 11 | 13 h 10 min |
| May | 76°F | 48°F | 62.3°F | 4.23 | 0.0 | 11 | 4 | 2 | 14 h 20 min |
| June | 88°F | 60°F | 73.5°F | 3.51 | 0.0 | 10 | 12 | <1 | 15 h |
| July | 93°F | 65°F | 78.9°F | 4.92 | 0.0 | 10 | 20 | <1 | 14 h 40 min |
| August | 91°F | 63°F | 76.6°F | 3.85 | 0.0 | 9 | 18 | <1 | 13 h 50 min |
| September | 83°F | 53°F | 67.9°F | 2.64 | 0.0 | 6 | 9 | 1 | 12 h 30 min |
| October | 70°F | 39°F | 54.6°F | 2.11 | 0.4 | 6 | 2 | 9 | 11 h 10 min |
| November | 56°F | 26°F | 40.9°F | 1.19 | 2.1 | 5 | <1 | 24 | 10 h |
| December | 44°F | 18°F | 30.7°F | 0.93 | 3.3 | 3 | <1 | 30 | 9 h 20 min |
| Year (annual) | 68°F | 39°F | 53.2°F | 28.59 | 17.6 | 81 | 64 | 155 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −10°C | −2.2°C | 17 mm | 10 cm |
| February | 8°C | −8°C | −0.1°C | 18 mm | 12 cm |
| March | 14°C | −3°C | 5.5°C | 39 mm | 5 cm |
| April | 19°C | 2°C | 10.8°C | 58 mm | 3 cm |
| May | 25°C | 9°C | 16.8°C | 107 mm | 0 cm |
| June | 31°C | 15°C | 23.1°C | 89 mm | 0 cm |
| July | 34°C | 19°C | 26.1°C | 125 mm | 0 cm |
| August | 33°C | 17°C | 24.8°C | 98 mm | 0 cm |
| September | 28°C | 12°C | 19.9°C | 67 mm | 0 cm |
| October | 21°C | 4°C | 12.6°C | 54 mm | 1 cm |
| November | 13°C | −3°C | 4.9°C | 30 mm | 5 cm |
| December | 7°C | −8°C | −0.7°C | 24 mm | 8 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00140201; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Alton?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (6).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00140201.
When is the last frost in Alton?
In Alton, the last spring frost (32°F) comes after April 29 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 12 in half of years and before September 28 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 291 year in 10 after May 11; 9 in 10 after April 16
- First autumn frost, half of years before
- October 121 year in 10 before September 28; 9 in 10 before October 27
NOAA puts the median frost-free season at 164 days, and the season without a hard freeze (28°F) at 182 days.
A hard freeze (28°F) comes after April 19 in half of springs and before October 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Alton in zone 6a in ZIP code 67623, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Alton's NOAA station is in zone 6a: the coldest night of a typical year reaches −9°F (22 complete years).
Frost dates for every NOAA station in Kansas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00140201; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Alton?
In a normal year in Alton, 64 days a year reach 90°F (16 of them 100°F or more), 155 nights fall to 32°F or colder and 81 days bring measurable precipitation.
- Days at 90°F or more
- 64a normal year
- Days at 100°F or more
- 16a normal year
- Nights at 32°F or colder
- 155a normal year
- Days that stay below freezing
- 25high of 32°F or less
- Days with 0.01 inch of precipitation
- 81a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1902) is 121°F, on July 24, 1936; the lowest is −31°F, on December 23, 1989.
The wettest calendar year on that record is 1993, with 52.63 in; the snowiest season is 1931–32, with 48.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00140201; records: ACIS (NOAA Regional Climate Centers), station USC00140201. Records use complete months only; a month missing more than three days is left out.
How sunny is Alton?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Alton, 4.6 kWh per square metre a day. July is the sunniest month (86%) and February the cloudiest (75%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 76% | 2.4 |
| February | 75% | 3.2 |
| March | 75% | 4.3 |
| April | 75% | 5.4 |
| May | 77% | 6.2 |
| June | 84% | 7.0 |
| July | 86% | 6.8 |
| August | 85% | 6.0 |
| September | 83% | 4.9 |
| October | 79% | 3.6 |
| November | 80% | 2.7 |
| December | 76% | 2.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Alton need?
A normal year in Alton brings 5,584 heating degree days, 4% more than the median U.S. place (5,373), and 1,334 cooling degree days, 47% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,801 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,147 | 0 |
| February | 925 | 0 |
| March | 717 | 0 |
| April | 416 | 10 |
| May | 156 | 72 |
| June | 18 | 274 |
| July | 1 | 433 |
| August | 4 | 363 |
| September | 70 | 157 |
| October | 345 | 24 |
| November | 725 | 1 |
| December | 1,061 | 0 |
| Year (annual) | 5,584 | 1,334 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00140201. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Alton's climate compare?
Alton is warmer than 28 of the other 136 places with their own NOAA record in Kansas, and wetter than 56. Across the 7,247 U.S. stations with normals, its annual mean of 53.2°F is warmer than 54%.
In the Köppen classification computed from these normals, Alton is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Alton share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Osborne, KS1,274 people · 15 mi E
- Woodston, KS89 people · 7 mi W
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Alton's climate
What is the coldest month in Alton?
January, with a normal high of 42°F and a normal low of 14°F. The warmest is July (93°F by day, 65°F at night).
Does it snow in Alton?
Yes: 18 inches in a normal year, falling on 9 days with 0.1 inch or more, the most in February (4.8 inches).
What is the rainiest month in Alton?
July, with 4.92 in of precipitation in a normal year; the driest is January with 0.67 in.
What plant hardiness zone is Alton in?
The USDA's 2023 map puts Alton in zone 6a in ZIP code 67623, the nearest ZIP area. By the same method at Alton's NOAA station, the coldest night of a typical year reaches −9°F (22 years, 1991-2020): zone 6a.
How late can frost come in Alton?
In half of years the last 32°F night comes after April 29; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Kansas climateThe statewide normals and every place in the state
- Kirwin, KS15 miles from this station, 52.1°F a year
- Smith Center, KS23 miles from this station, 53.1°F a year
- Webster Dam, KS24 miles from this station, 53.9°F a year
- Phillipsburg, KS26 miles from this station, 53.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made