Glenwood, Iowa climate: Normal weather by month, frost dates and records
Glenwood's normal year runs from 12°F January nights to 87°F July afternoons, with 34.8 inches of precipitation and 24 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.5°C, January lows of −11°C, July highs of 31°C, 884 mm of precipitation a year.
- NOAA stationGlenwood (3 mi SW)
- Station IDUSC00133290
- Location41.01°N 95.77°W
- Elevation980 ft (299 m)
- From the center3 miles
- Population5,250
On October 23, the normal high in Glenwood is 63°F and the normal low 37°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 Glenwood.
- Jan 33° 12°
- Feb 38° 16°
- Mar 52° 28°
- Apr 64° 38°
- May 74° 50°
- Jun 83° 61°
- Jul 87° 65°
- Aug 85° 62°
- Sep 79° 53°
- Oct 67° 40°
- Nov 51° 28°
- Dec 38° 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 Glenwood each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 12°F. The most precipitation falls in June (5.96 in), the least in January (0.66 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 12°F | 22.6°F | 0.66 | 8.2 | 5 | <1 | 30 | 9 h 30 min |
| February | 38°F | 16°F | 27.3°F | 1.03 | 7.0 | 5 | <1 | 26 | 10 h 40 min |
| March | 52°F | 28°F | 39.5°F | 2.03 | 3.4 | 7 | <1 | 22 | 11 h 50 min |
| April | 64°F | 38°F | 50.9°F | 3.73 | 0.4 | 10 | 1 | 9 | 13 h 20 min |
| May | 74°F | 50°F | 62.2°F | 5.19 | 0.0 | 12 | 2 | 1 | 14 h 30 min |
| June | 83°F | 61°F | 72.3°F | 5.96 | 0.0 | 9 | 6 | <1 | 15 h 10 min |
| July | 87°F | 65°F | 75.8°F | 4.31 | 0.0 | 10 | 11 | <1 | 14 h 50 min |
| August | 85°F | 62°F | 73.6°F | 3.81 | 0.0 | 7 | 9 | <1 | 13 h 50 min |
| September | 79°F | 53°F | 66.1°F | 3.32 | 0.0 | 6 | 5 | 1 | 12 h 30 min |
| October | 67°F | 40°F | 53.3°F | 2.30 | 0.0 | 6 | 1 | 7 | 11 h 10 min |
| November | 51°F | 28°F | 39.2°F | 1.30 | 1.3 | 5 | <1 | 21 | 10 h |
| December | 38°F | 18°F | 27.6°F | 1.16 | 3.4 | 4 | <1 | 29 | 9 h 10 min |
| Year (annual) | 63°F | 39°F | 50.9°F | 34.80 | 23.7 | 84 | 34 | 146 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −11°C | −5.2°C | 17 mm | 21 cm |
| February | 3°C | −9°C | −2.6°C | 26 mm | 18 cm |
| March | 11°C | −2°C | 4.2°C | 52 mm | 9 cm |
| April | 18°C | 3°C | 10.5°C | 95 mm | 1 cm |
| May | 23°C | 10°C | 16.8°C | 132 mm | 0 cm |
| June | 29°C | 16°C | 22.4°C | 151 mm | 0 cm |
| July | 31°C | 18°C | 24.3°C | 109 mm | 0 cm |
| August | 30°C | 17°C | 23.1°C | 97 mm | 0 cm |
| September | 26°C | 12°C | 18.9°C | 84 mm | 0 cm |
| October | 19°C | 4°C | 11.8°C | 58 mm | 0 cm |
| November | 10°C | −2°C | 4.0°C | 33 mm | 3 cm |
| December | 3°C | −8°C | −2.4°C | 29 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00133290; 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 Glenwood?
Normal highs sit between 65°F and 85°F in May, June, 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 USC00133290.
When is the last frost in Glenwood?
In Glenwood, the last spring frost (32°F) comes after April 23 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 11 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 231 year in 10 after May 6; 9 in 10 after April 9
- First autumn frost, half of years before
- October 111 year in 10 before September 27; 9 in 10 before October 25
NOAA puts the median frost-free season at 170 days, and the season without a hard freeze (28°F) at 190 days.
A hard freeze (28°F) comes after April 12 in half of springs and before October 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glenwood in zone 6a in ZIP code 51534, 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 USC00133290; 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 Glenwood?
In a normal year in Glenwood, 34 days a year reach 90°F (1 of them 100°F or more), 146 nights fall to 32°F or colder and 84 days bring measurable precipitation.
- Days at 90°F or more
- 34a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 146a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 84a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1893) is 115°F, on July 25, 1936; the lowest is −30°F, on December 23, 1983.
The wettest calendar year on that record is 1998, with 47.91 in; the snowiest season is 1941–42, with 64.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00133290; records: ACIS (NOAA Regional Climate Centers), station USC00133290. Records use complete months only; a month missing more than three days is left out.
How sunny is Glenwood?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Glenwood, 4.2 kWh per square metre a day. July is the sunniest month (83%) and December the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 2.0 |
| February | 74% | 3.0 |
| March | 69% | 3.8 |
| April | 70% | 4.9 |
| May | 73% | 5.8 |
| June | 79% | 6.5 |
| July | 83% | 6.5 |
| August | 81% | 5.6 |
| September | 81% | 4.6 |
| October | 75% | 3.2 |
| November | 74% | 2.3 |
| December | 69% | 1.7 |
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 Glenwood need?
A normal year in Glenwood brings 6,188 heating degree days, 15% more than the median U.S. place (5,373), and 1,070 cooling degree days, 18% 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 3,476 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,314 | 0 |
| February | 1,055 | 0 |
| March | 792 | 1 |
| April | 435 | 13 |
| May | 159 | 72 |
| June | 16 | 235 |
| July | 2 | 336 |
| August | 6 | 272 |
| September | 90 | 122 |
| October | 383 | 18 |
| November | 776 | 1 |
| December | 1,161 | 0 |
| Year (annual) | 6,188 | 1,070 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00133290. 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 Glenwood's climate compare?
Glenwood is warmer than 122 of the other 131 places with their own NOAA record in Iowa, and wetter than 37. Across the 7,247 U.S. stations with normals, its annual mean of 50.9°F is warmer than 44%.
In the Köppen classification computed from these normals, Glenwood 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 Glenwood share this climate record?
12 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.
- Bellevue, NEalso near: Springfield (7 mi, 50.6°F a year); Omaha (12 mi, 52.4°F a year)64,777 people · 13 mi NW
- Plattsmouth, NE6,887 people · 6 mi W
- Offutt AFB, NE5,663 people · 11 mi NW
- Beaver Lake, NE2,198 people · 8 mi SW
- Buccaneer Bay, NE1,361 people · 10 mi W
- Malvern, IA1,056 people · 10 mi E
- Murray, NE499 people · 10 mi SW
- Silver City, IA244 people · 10 mi NE
- Nehawka, NE173 people · 17 mi SW
- Lake Waconda, NE161 people · 12 mi S
- Pacific Junction, IA99 people · 1 mi NW
- La Platte, NE35 people · 9 mi NW
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 Glenwood's climate
What is the coldest month in Glenwood?
January, with a normal high of 33°F and a normal low of 12°F. The warmest is July (87°F by day, 65°F at night).
Does it snow in Glenwood?
Yes: 24 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (8.2 inches).
What is the rainiest month in Glenwood?
June, with 5.96 in of precipitation in a normal year; the driest is January with 0.66 in.
What plant hardiness zone is Glenwood in?
The USDA's 2023 map puts Glenwood in zone 6a in ZIP code 51534, the nearest ZIP area.
How late can frost come in Glenwood?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 6. Waiting until May 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Springfield, NE12 miles from this station, 50.6°F a year
- Sidney, IA20 miles from this station, 50.7°F a year
- Weeping Water, NE22 miles from this station, 51.2°F a year
- Omaha, NE22 miles from this station, 52.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made