Marion, Iowa climate: Normal weather by month, frost dates and records
Marion's normal year runs from 13°F January nights to 86°F July afternoons, with 38.8 inches of precipitation and 34 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.9°C, January lows of −11°C, July highs of 30°C, 984 mm of precipitation a year.
- NOAA stationCedar Rapids #1
- Station IDUSC00131319
- Location42.05°N 91.59°W
- Elevation813 ft (248 m)
- Population42,542
On October 14, the normal high in Marion is 65°F and the normal low 42°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Marion.
- Jan 30° 13°
- Feb 35° 17°
- Mar 49° 28°
- Apr 63° 38°
- May 74° 50°
- Jun 82° 60°
- Jul 86° 63°
- Aug 83° 61°
- Sep 77° 53°
- Oct 64° 42°
- Nov 48° 29°
- Dec 35° 19°
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 Marion each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 13°F. The most precipitation falls in June (5.68 in), the least in January (1.17 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 30°F | 13°F | 21.3°F | 1.17 | 8.7 | 9 | <1 | 30 | 9 h 30 min |
| February | 35°F | 17°F | 25.9°F | 1.34 | 8.3 | 8 | <1 | 25 | 10 h 30 min |
| March | 49°F | 28°F | 38.2°F | 2.06 | 4.0 | 10 | <1 | 20 | 11 h 50 min |
| April | 63°F | 38°F | 50.9°F | 4.02 | 1.5 | 11 | <1 | 7 | 13 h 20 min |
| May | 74°F | 50°F | 61.7°F | 4.74 | 0.0 | 13 | 1 | 1 | 14 h 30 min |
| June | 82°F | 60°F | 71.0°F | 5.68 | 0.0 | 12 | 4 | <1 | 15 h 10 min |
| July | 86°F | 63°F | 74.4°F | 4.47 | 0.0 | 10 | 7 | <1 | 15 h |
| August | 83°F | 61°F | 72.3°F | 4.42 | 0.0 | 10 | 4 | <1 | 14 h |
| September | 77°F | 53°F | 65.2°F | 3.96 | 0.0 | 9 | 2 | <1 | 12 h 30 min |
| October | 64°F | 42°F | 52.8°F | 3.00 | 0.6 | 10 | <1 | 5 | 11 h 10 min |
| November | 48°F | 29°F | 38.7°F | 2.22 | 2.2 | 8 | <1 | 18 | 9 h 50 min |
| December | 35°F | 19°F | 26.7°F | 1.67 | 9.0 | 9 | <1 | 28 | 9 h 10 min |
| Year (annual) | 61°F | 39°F | 49.9°F | 38.75 | 34.3 | 118 | 18 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −11°C | −5.9°C | 30 mm | 22 cm |
| February | 2°C | −9°C | −3.4°C | 34 mm | 21 cm |
| March | 9°C | −2°C | 3.4°C | 52 mm | 10 cm |
| April | 17°C | 4°C | 10.5°C | 102 mm | 4 cm |
| May | 23°C | 10°C | 16.5°C | 120 mm | 0 cm |
| June | 28°C | 15°C | 21.7°C | 144 mm | 0 cm |
| July | 30°C | 17°C | 23.6°C | 114 mm | 0 cm |
| August | 29°C | 16°C | 22.4°C | 112 mm | 0 cm |
| September | 25°C | 12°C | 18.4°C | 101 mm | 0 cm |
| October | 18°C | 5°C | 11.6°C | 76 mm | 2 cm |
| November | 9°C | −1°C | 3.7°C | 56 mm | 6 cm |
| December | 2°C | −7°C | −2.9°C | 42 mm | 23 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00131319; 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 Marion?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, September has the fewest days with rain (9).
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 USC00131319.
When is the last frost in Marion?
In Marion, the last spring frost (32°F) comes after April 28 in half of years and after May 13 in one year in ten; the first autumn frost comes before October 12 in half of years and before September 29 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 281 year in 10 after May 13; 9 in 10 after April 14
- First autumn frost, half of years before
- October 121 year in 10 before September 29; 9 in 10 before October 25
NOAA puts the median frost-free season at 166 days, and the season without a hard freeze (28°F) at 186 days.
A hard freeze (28°F) comes after April 17 in half of springs and before October 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Marion in zone 5a in ZIP code 52302. By the map's own method, the average of each year's coldest night over 1991-2020, Marion's NOAA station is in zone 5b: the coldest night of a typical year reaches −15°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Iowa · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00131319; 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 Marion?
In a normal year in Marion, 18 days a year reach 90°F (1 of them 100°F or more), 134 nights fall to 32°F or colder and 118 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 49high of 32°F or less
- Days with 0.01 inch of precipitation
- 118a normal year
- Days with 1 inch of snow or more
- 11a normal year
The highest temperature in this station's record (since 1892) is 110°F, on July 6, 1911; the lowest is −33°F, on January 16, 2009.
The wettest calendar year on that record is 1993, with 60.12 in; the snowiest season is 1959–60, with 62.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00131319; records: ACIS (NOAA Regional Climate Centers), station USC00131319. Records use complete months only; a month missing more than three days is left out.
How sunny is Marion?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Marion, 4.0 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.8 |
| February | 72% | 2.9 |
| March | 70% | 3.8 |
| April | 68% | 4.7 |
| May | 71% | 5.6 |
| June | 75% | 6.2 |
| July | 80% | 6.3 |
| August | 80% | 5.5 |
| September | 79% | 4.4 |
| October | 70% | 2.9 |
| November | 69% | 2.0 |
| December | 63% | 1.5 |
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 Marion need?
A normal year in Marion brings 6,384 heating degree days, 19% more than the median U.S. place (5,373), and 918 cooling degree days, 1% 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 3,266 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,356 | 0 |
| February | 1,096 | 0 |
| March | 833 | 2 |
| April | 434 | 10 |
| May | 166 | 64 |
| June | 21 | 200 |
| July | 3 | 294 |
| August | 8 | 234 |
| September | 97 | 101 |
| October | 392 | 14 |
| November | 789 | 0 |
| December | 1,189 | 0 |
| Year (annual) | 6,384 | 918 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00131319. 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.
Has Marion been warmer than normal lately?
2025 averaged 52.1°F, 2.2°F above the 1991-2020 normal of 49.9°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.0°F | +2.1°F | 31.99 | 29.5 |
| 2023 | 53.0°F | +3.1°F | 26.77 | 32.7 |
| 2024 | 53.6°F | +3.7°F | 43.06 | 31.4 |
| 2025 | 52.1°F | +2.2°F | 37.43 | 34.2 |
Over 124 complete years from 1893 to 2025, the station's annual mean temperature rose at a fitted 2.1°F per century (+0.12°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00131319; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Marion's climate compare?
Marion is warmer than 105 of the other 131 places with their own NOAA record in Iowa, and wetter than 109. Across the 7,247 U.S. stations with normals, its annual mean of 49.9°F is warmer than 40%.
In the Köppen classification computed from these normals, Marion 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 Marion share this climate record?
8 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.
- Hiawatha, IA7,347 people · 5 mi W
- Mount Vernon, IA4,518 people · 12 mi SE
- Robins, IA3,362 people · 5 mi NW
- Lisbon, IA2,238 people · 13 mi SE
- Palo, IA1,554 people · 11 mi W
- Springville, IA1,161 people · 7 mi E
- Alburnett, IA672 people · 7 mi N
- Bertram, IA267 people · 7 mi S
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 Marion's climate
What is the coldest month in Marion?
January, with a normal high of 30°F and a normal low of 13°F. The warmest is July (86°F by day, 63°F at night).
Does it snow in Marion?
Yes: 34 inches in a normal year, falling on 25 days with 0.1 inch or more, the most in December (9.0 inches).
What is the rainiest month in Marion?
June, with 5.68 in of precipitation in a normal year; the driest is January with 1.17 in.
What plant hardiness zone is Marion in?
The USDA's 2023 map puts Marion in zone 5a in ZIP code 52302. By the same method at Marion's NOAA station, the coldest night of a typical year reaches −15°F (30 years, 1991-2020): zone 5b.
How late can frost come in Marion?
In half of years the last 32°F night comes after April 28; in one year in ten it comes after May 13. Waiting until May 13 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Cedar Rapids, IA13 miles from this station, 48.2°F a year
- Anamosa, IA16 miles from this station, 47.0°F a year
- Coggon, IA16 miles from this station, 46.5°F a year
- Vinton, IA23 miles from this station, 46.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made