Clarion, Iowa climate: Normal weather by month, frost dates and records
Clarion's normal year runs from 6°F January nights to 85°F July afternoons, with 34.3 inches of precipitation and 31 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.3°C, January lows of −14°C, July highs of 29°C, 870 mm of precipitation a year.
- NOAA stationClarion
- Station IDUSC00131541
- Location42.72°N 93.73°W
- Elevation1,156 ft (352 m)
- From the centerunder 1 mile
- Population2,751
On October 23, the normal high in Clarion is 59°F and the normal low 35°F, and the chance of measurable rain or snow is 22%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Clarion.
- Jan 26° 6°
- Feb 31° 11°
- Mar 44° 25°
- Apr 59° 35°
- May 72° 48°
- Jun 82° 59°
- Jul 85° 62°
- Aug 82° 60°
- Sep 76° 51°
- Oct 63° 38°
- Nov 45° 25°
- Dec 31° 13°
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 Clarion each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 6°F. The most precipitation falls in June (5.81 in), the least in January (0.73 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 26°F | 6°F | 16.0°F | 0.73 | 8.9 | 5 | <1 | 31 | 9 h 20 min |
| February | 31°F | 11°F | 21.1°F | 0.91 | 6.2 | 5 | <1 | 27 | 10 h 30 min |
| March | 44°F | 25°F | 34.2°F | 1.96 | 5.7 | 6 | <1 | 25 | 11 h 50 min |
| April | 59°F | 35°F | 47.0°F | 3.75 | 1.4 | 9 | <1 | 13 | 13 h 20 min |
| May | 72°F | 48°F | 59.6°F | 4.81 | 0.0 | 12 | 1 | 1 | 14 h 40 min |
| June | 82°F | 59°F | 70.3°F | 5.81 | 0.0 | 11 | 4 | <1 | 15 h 20 min |
| July | 85°F | 62°F | 73.4°F | 4.04 | 0.0 | 9 | 7 | <1 | 15 h |
| August | 82°F | 60°F | 71.1°F | 4.10 | 0.0 | 8 | 3 | <1 | 14 h |
| September | 76°F | 51°F | 63.6°F | 3.13 | 0.0 | 7 | 2 | 1 | 12 h 30 min |
| October | 63°F | 38°F | 50.7°F | 2.29 | 0.1 | 7 | <1 | 10 | 11 h 10 min |
| November | 45°F | 25°F | 35.1°F | 1.52 | 2.9 | 6 | <1 | 24 | 9 h 50 min |
| December | 31°F | 13°F | 22.2°F | 1.22 | 5.9 | 5 | <1 | 30 | 9 h |
| Year (annual) | 58°F | 36°F | 47.0°F | 34.27 | 31.1 | 88 | 16 | 161 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −14°C | −8.9°C | 19 mm | 23 cm |
| February | 0°C | −12°C | −6.1°C | 23 mm | 16 cm |
| March | 7°C | −4°C | 1.2°C | 50 mm | 14 cm |
| April | 15°C | 2°C | 8.3°C | 95 mm | 4 cm |
| May | 22°C | 9°C | 15.3°C | 122 mm | 0 cm |
| June | 28°C | 15°C | 21.3°C | 148 mm | 0 cm |
| July | 29°C | 17°C | 23.0°C | 103 mm | 0 cm |
| August | 28°C | 16°C | 21.7°C | 104 mm | 0 cm |
| September | 25°C | 11°C | 17.6°C | 80 mm | 0 cm |
| October | 17°C | 3°C | 10.4°C | 58 mm | 0 cm |
| November | 7°C | −4°C | 1.7°C | 39 mm | 7 cm |
| December | 0°C | −11°C | −5.4°C | 31 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00131541; 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 Clarion?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (7).
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 USC00131541.
When is the last frost in Clarion?
In Clarion, the last spring frost (32°F) comes after April 30 in half of years and after May 12 in one year in ten; the first autumn frost comes before October 10 in half of years and before September 27 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 301 year in 10 after May 12; 9 in 10 after April 17
- First autumn frost, half of years before
- October 101 year in 10 before September 27; 9 in 10 before October 21
NOAA puts the median frost-free season at 162 days, and the season without a hard freeze (28°F) at 181 days.
A hard freeze (28°F) comes after April 19 in half of springs and before October 19 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Clarion in zone 5a in ZIP code 50525, the nearest ZIP area.
Frost dates for every NOAA station in Iowa · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00131541; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Clarion?
In a normal year in Clarion, 16 days a year reach 90°F, 161 nights fall to 32°F or colder and 88 days bring measurable precipitation.
- Days at 90°F or more
- 16a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 161a normal year
- Days that stay below freezing
- 68high of 32°F or less
- Days with 0.01 inch of precipitation
- 88a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1944) is 103°F, on July 31, 1955; the lowest is −32°F, on January 21, 1970.
The wettest calendar year on that record is 1993, with 48.06 in; the snowiest season is 1961–62, with 67.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00131541; records: ACIS (NOAA Regional Climate Centers), station USC00131541. Records use complete months only; a month missing more than three days is left out.
How sunny is Clarion?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Clarion, 4.0 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 1.9 |
| February | 75% | 3.0 |
| March | 70% | 3.8 |
| April | 69% | 4.8 |
| May | 71% | 5.6 |
| June | 76% | 6.2 |
| July | 82% | 6.4 |
| August | 80% | 5.5 |
| September | 79% | 4.4 |
| October | 72% | 3.0 |
| November | 71% | 2.1 |
| December | 66% | 1.6 |
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 Clarion need?
A normal year in Clarion brings 7,309 heating degree days, 36% more than the median U.S. place (5,373), and 804 cooling degree days, 11% fewer 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 2,971 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,519 | 0 |
| February | 1,228 | 0 |
| March | 954 | 0 |
| April | 545 | 5 |
| May | 216 | 50 |
| June | 27 | 185 |
| July | 6 | 268 |
| August | 14 | 203 |
| September | 125 | 83 |
| October | 454 | 10 |
| November | 897 | 0 |
| December | 1,327 | 0 |
| Year (annual) | 7,309 | 804 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00131541. 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 Clarion's climate compare?
Clarion is warmer than 45 of the other 131 places with their own NOAA record in Iowa, and wetter than 32. Across the 7,247 U.S. stations with normals, its annual mean of 47.0°F is warmer than 28%.
In the Köppen classification computed from these normals, Clarion 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 Clarion share this climate record?
7 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.
- Eagle Grove, IA3,615 people · 9 mi SW
- Belmond, IA2,405 people · 11 mi NE
- Goldfield, IA617 people · 9 mi W
- Dows, IA509 people · 12 mi E
- Alexander, IA165 people · 14 mi NE
- Rowan, IA118 people · 9 mi E
- Galt, IA22 people · 7 mi E
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 Clarion's climate
What is the coldest month in Clarion?
January, with a normal high of 26°F and a normal low of 6°F. The warmest is July (85°F by day, 62°F at night).
Does it snow in Clarion?
Yes: 31 inches in a normal year, falling on 18 days with 0.1 inch or more, the most in January (8.9 inches).
What is the rainiest month in Clarion?
June, with 5.81 in of precipitation in a normal year; the driest is January with 0.73 in.
What plant hardiness zone is Clarion in?
The USDA's 2023 map puts Clarion in zone 5a in ZIP code 50525, the nearest ZIP area.
How late can frost come in Clarion?
In half of years the last 32°F night comes after April 30; in one year in ten it comes after May 12. Waiting until May 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Webster City, IA17 miles from this station, 46.1°F a year
- Dakota City, IA24 miles from this station, 46.8°F a year
- Humboldt, IA25 miles from this station, 46.2°F a year
- Fort Dodge, IA25 miles from this station, 46.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made