Le Mars, Iowa climate: Normal weather by month, frost dates and records
Le Mars's normal year runs from 7°F January nights to 85°F July afternoons, with 30.0 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, 762 mm of precipitation a year.
- NOAA stationLe Mars
- Station IDUSC00134735
- Location42.78°N 96.15°W
- Elevation1,195 ft (364 m)
- From the center1 miles
- Population10,674
On October 23, the normal high in Le Mars is 59°F and the normal low 34°F, and the chance of measurable rain or snow is 17%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Le Mars.
- Jan 27° 7°
- Feb 32° 11°
- Mar 46° 23°
- Apr 60° 34°
- May 72° 47°
- Jun 81° 58°
- Jul 85° 62°
- Aug 82° 59°
- Sep 76° 50°
- Oct 63° 37°
- Nov 46° 24°
- Dec 32° 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 Le Mars each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 7°F. The most precipitation falls in June (4.64 in), the least in January (0.72 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 27°F | 7°F | 17.3°F | 0.72 | 7.8 | 4 | <1 | 31 | 9 h 20 min |
| February | 32°F | 11°F | 21.8°F | 0.87 | 7.5 | 5 | <1 | 27 | 10 h 30 min |
| March | 46°F | 23°F | 34.5°F | 1.85 | 4.6 | 6 | <1 | 25 | 11 h 50 min |
| April | 60°F | 34°F | 47.0°F | 3.07 | 1.9 | 8 | <1 | 12 | 13 h 20 min |
| May | 72°F | 47°F | 59.3°F | 3.90 | 0.1 | 10 | 2 | 1 | 14 h 40 min |
| June | 81°F | 58°F | 69.8°F | 4.64 | 0.0 | 10 | 4 | <1 | 15 h 20 min |
| July | 85°F | 62°F | 73.1°F | 3.11 | 0.0 | 7 | 6 | <1 | 15 h |
| August | 82°F | 59°F | 70.5°F | 3.95 | 0.0 | 8 | 3 | <1 | 14 h |
| September | 76°F | 50°F | 62.7°F | 3.14 | 0.0 | 7 | 1 | 1 | 12 h 30 min |
| October | 63°F | 37°F | 49.7°F | 2.40 | 0.4 | 6 | <1 | 10 | 11 h 10 min |
| November | 46°F | 24°F | 34.6°F | 1.30 | 2.6 | 4 | <1 | 24 | 9 h 50 min |
| December | 32°F | 13°F | 22.4°F | 1.04 | 6.0 | 4 | <1 | 30 | 9 h |
| Year (annual) | 58°F | 35°F | 46.9°F | 29.99 | 30.9 | 77 | 17 | 160 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −14°C | −8.2°C | 18 mm | 20 cm |
| February | 0°C | −11°C | −5.7°C | 22 mm | 19 cm |
| March | 8°C | −5°C | 1.4°C | 47 mm | 12 cm |
| April | 16°C | 1°C | 8.3°C | 78 mm | 5 cm |
| May | 22°C | 8°C | 15.2°C | 99 mm | 0 cm |
| June | 27°C | 15°C | 21.0°C | 118 mm | 0 cm |
| July | 29°C | 17°C | 22.8°C | 79 mm | 0 cm |
| August | 28°C | 15°C | 21.4°C | 100 mm | 0 cm |
| September | 24°C | 10°C | 17.1°C | 80 mm | 0 cm |
| October | 17°C | 3°C | 9.8°C | 61 mm | 1 cm |
| November | 8°C | −5°C | 1.4°C | 33 mm | 7 cm |
| December | 0°C | −11°C | −5.3°C | 26 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00134735; 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 Le Mars?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, July 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 USC00134735.
When is the last frost in Le Mars?
In Le Mars, 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 4 in half of years and before September 21 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 41 year in 10 before September 21; 9 in 10 before October 19
NOAA puts the median frost-free season at 157 days, and the season without a hard freeze (28°F) at 178 days.
A hard freeze (28°F) comes after April 20 in half of springs and before October 16 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Le Mars in zone 5a in ZIP code 51031, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Le Mars's NOAA station is in zone 5a: the coldest night of a typical year reaches −18°F (25 complete years).
Frost dates for every NOAA station in Iowa · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00134735; 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 Le Mars?
In a normal year in Le Mars, 17 days a year reach 90°F, 160 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 160a normal year
- Days that stay below freezing
- 61high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
- Days with 1 inch of snow or more
- 9a normal year
The highest temperature in this station's record (since 1896) is 111°F, on July 17, 1936; the lowest is −37°F, on January 12, 1912.
The wettest calendar year on that record is 1951, with 42.35 in; the snowiest season is 1983–84, with 67.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00134735; records: ACIS (NOAA Regional Climate Centers), station USC00134735. Records use complete months only; a month missing more than three days is left out.
How sunny is Le Mars?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Le Mars, 4.2 kWh per square metre a day. July is the sunniest month (84%) and December the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.0 |
| February | 77% | 3.1 |
| March | 70% | 3.8 |
| April | 71% | 5.0 |
| May | 72% | 5.8 |
| June | 79% | 6.5 |
| July | 84% | 6.6 |
| August | 81% | 5.6 |
| September | 80% | 4.5 |
| October | 75% | 3.1 |
| November | 75% | 2.2 |
| December | 69% | 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 Le Mars need?
A normal year in Le Mars brings 7,312 heating degree days, 36% more than the median U.S. place (5,373), and 756 cooling degree days, 17% 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 2,887 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,479 | 0 |
| February | 1,210 | 0 |
| March | 946 | 1 |
| April | 543 | 5 |
| May | 225 | 50 |
| June | 32 | 176 |
| July | 6 | 257 |
| August | 17 | 188 |
| September | 142 | 73 |
| October | 482 | 8 |
| November | 912 | 0 |
| December | 1,319 | 0 |
| Year (annual) | 7,312 | 756 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00134735. 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 Le Mars been warmer than normal lately?
2025 averaged 48.9°F, 2.0°F above the 1991-2020 normal of 46.9°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.6°F | +2.7°F | 24.20 | 23.5 |
| 2022 | 47.2°F | +0.3°F | 19.94 | 15.8 |
| 2023 | 49.4°F | +2.5°F | 29.63 | 27.9 |
| 2024 | 50.0°F | +3.1°F | 32.80 | 26.1 |
| 2025 | 48.9°F | +2.0°F | 30.92 | 25.6 |
Over 106 complete years from 1898 to 2025, the station's annual mean temperature rose at a fitted 1.2°F per century (+0.07°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00134735; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Le Mars's climate compare?
Le Mars is warmer than 41 of the other 131 places with their own NOAA record in Iowa, and wetter than 9. Across the 7,247 U.S. stations with normals, its annual mean of 46.9°F is warmer than 27%.
In the Köppen classification computed from these normals, Le Mars 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 Le Mars 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.
- Remsen, IA1,681 people · 9 mi E
- Kingsley, IA1,394 people · 16 mi SE
- Hinton, IA959 people · 13 mi SW
- Merrill, IA713 people · 7 mi SW
- Brunsville, IA128 people · 6 mi W
- Oyens, IA88 people · 5 mi NE
- Craig, IA78 people · 11 mi NW
- Struble, IA72 people · 8 mi N
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 Le Mars's climate
What is the coldest month in Le Mars?
January, with a normal high of 27°F and a normal low of 7°F. The warmest is July (85°F by day, 62°F at night).
Does it snow in Le Mars?
Yes: 31 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (7.8 inches).
What is the rainiest month in Le Mars?
June, with 4.64 in of precipitation in a normal year; the driest is January with 0.72 in.
What plant hardiness zone is Le Mars in?
The USDA's 2023 map puts Le Mars in zone 5a in ZIP code 51031, the nearest ZIP area. By the same method at Le Mars's NOAA station, the coldest night of a typical year reaches −18°F (25 years, 1991-2020): zone 5a.
How late can frost come in Le Mars?
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
- Sioux Center, IA19 miles from this station, 48.0°F a year
- Hawarden, IA23 miles from this station, 46.7°F a year
- Sioux City Ang, IA29 miles from this station, 48.0°F a year
- Sioux City, IA29 miles from this station, 48.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made