Stanley, Iowa climate: Normal weather by month, frost dates and records
Stanley's normal year runs from 7°F January nights to 82°F July afternoons, with 38.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.4°C, January lows of −14°C, July highs of 28°C, 982 mm of precipitation a year.
- NOAA stationStanley
- Station IDUSC00137892
- Location42.63°N 91.86°W
- Elevation1,114 ft (340 m)
- From the center3 miles
- Population86
On October 23, the normal high in Stanley is 57°F and the normal low 33°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Stanley.
- Jan 25° 7°
- Feb 29° 9°
- Mar 43° 23°
- Apr 58° 34°
- May 70° 46°
- Jun 79° 57°
- Jul 82° 59°
- Aug 80° 57°
- Sep 74° 48°
- Oct 61° 36°
- Nov 44° 24°
- Dec 31° 14°
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 Stanley each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 7°F. The most precipitation falls in June (5.76 in), the least in February (1.18 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 25°F | 7°F | 15.8°F | 1.19 | – | <1 | 31 | 9 h 20 min |
| February | 29°F | 9°F | 19.3°F | 1.18 | – | <1 | 28 | 10 h 30 min |
| March | 43°F | 23°F | 33.1°F | 2.02 | – | <1 | 25 | 11 h 50 min |
| April | 58°F | 34°F | 45.6°F | 3.96 | – | <1 | 14 | 13 h 20 min |
| May | 70°F | 46°F | 57.9°F | 4.84 | – | 1 | 2 | 14 h 40 min |
| June | 79°F | 57°F | 68.2°F | 5.76 | – | 2 | <1 | 15 h 20 min |
| July | 82°F | 59°F | 70.5°F | 5.25 | – | 4 | <1 | 15 h |
| August | 80°F | 57°F | 68.1°F | 3.98 | – | 2 | <1 | 14 h |
| September | 74°F | 48°F | 60.9°F | 3.71 | – | 1 | 1 | 12 h 30 min |
| October | 61°F | 36°F | 48.5°F | 3.10 | – | <1 | 12 | 11 h 10 min |
| November | 44°F | 24°F | 34.3°F | 2.07 | – | <1 | 23 | 9 h 50 min |
| December | 31°F | 14°F | 22.4°F | 1.59 | – | <1 | 30 | 9 h |
| Year (annual) | 56°F | 35°F | 45.4°F | 38.65 | – | 9 | 163 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −4°C | −14°C | −9.0°C | 30 mm |
| February | −1°C | −13°C | −7.1°C | 30 mm |
| March | 6°C | −5°C | 0.6°C | 51 mm |
| April | 14°C | 1°C | 7.6°C | 101 mm |
| May | 21°C | 8°C | 14.4°C | 123 mm |
| June | 26°C | 14°C | 20.1°C | 146 mm |
| July | 28°C | 15°C | 21.4°C | 133 mm |
| August | 26°C | 14°C | 20.1°C | 101 mm |
| September | 23°C | 9°C | 16.1°C | 94 mm |
| October | 16°C | 2°C | 9.2°C | 79 mm |
| November | 7°C | −4°C | 1.3°C | 53 mm |
| December | −1°C | −10°C | −5.3°C | 40 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Oelwein (1 mi E) (3 miles away), gets 39 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137892; 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 Stanley?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
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 USC00137892.
When is the last frost in Stanley?
In Stanley, the last spring frost (32°F) comes after May 4 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 16 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
- May 41 year in 10 after May 15; 9 in 10 after April 21
- First autumn frost, half of years before
- October 11 year in 10 before September 16; 9 in 10 before October 15
NOAA puts the median frost-free season at 150 days, and the season without a hard freeze (28°F) at 169 days.
A hard freeze (28°F) comes after April 24 in half of springs and before October 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Stanley in zone 5a in ZIP code 50671, 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 USC00137892; 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 Stanley?
In a normal year in Stanley, 9 days a year reach 90°F and 163 nights fall to 32°F or colder.
- Days at 90°F or more
- 9a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 163a normal year
- Days that stay below freezing
- 69high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00137892.
How sunny is Stanley?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Stanley, 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 Stanley need?
A normal year in Stanley brings 7,646 heating degree days, 42% more than the median U.S. place (5,373), and 537 cooling degree days, 41% 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 2,547 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,525 | 0 |
| February | 1,279 | 0 |
| March | 989 | 0 |
| April | 583 | 2 |
| May | 255 | 36 |
| June | 35 | 130 |
| July | 15 | 185 |
| August | 34 | 129 |
| September | 173 | 49 |
| October | 518 | 6 |
| November | 921 | 0 |
| December | 1,319 | 0 |
| Year (annual) | 7,646 | 537 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137892. 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 Stanley been warmer than normal lately?
2025 averaged 47.3°F, 1.9°F above the 1991-2020 normal of 45.4°F. 3 of the 4 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 44.6°F | −0.8°F | 38.75 |
| 2023 | 48.4°F | +3.0°F | 28.31 |
| 2024 | 49.5°F | +4.1°F | 39.38 |
| 2025 | 47.3°F | +1.9°F | 37.31 |
Source: observed years: ACIS, station USC00137892. A year counts only with all twelve months complete.
How does Stanley's climate compare?
Stanley is warmer than 11 of the other 131 places with their own NOAA record in Iowa, and wetter than 106. Across the 7,247 U.S. stations with normals, its annual mean of 45.4°F is warmer than 21%.
In the Köppen classification computed from these normals, Stanley is Dfb: continental, no dry season, warm 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 Stanley 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.
- Lamont, IA429 people · 12 mi E
- Aurora, IA165 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 Stanley's climate
What is the coldest month in Stanley?
January, with a normal high of 25°F and a normal low of 7°F. The warmest is July (82°F by day, 59°F at night).
Does it snow in Stanley?
Yes. NOAA publishes no 1991-2020 snowfall normal for Stanley's NOAA station; the nearest record that keeps one, Oelwein (1 mi E) (3 miles away), records 39 inches of snow in a normal year.
What is the rainiest month in Stanley?
June, with 5.76 in of precipitation in a normal year; the driest is February with 1.18 in.
What plant hardiness zone is Stanley in?
The USDA's 2023 map puts Stanley in zone 5a in ZIP code 50671, the nearest ZIP area.
How late can frost come in Stanley?
In half of years the last 32°F night comes after May 4; in one year in ten it comes after May 15. Waiting until May 15 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Oelwein, IA2 miles from this station, 46.3°F a year
- Independence, IA7 miles from this station, 47.0°F a year
- Fayette, IA17 miles from this station, 45.0°F a year
- Elkader, IA23 miles from this station, 45.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made