Storm Lake, Iowa climate: Normal weather by month, frost dates and records
Storm Lake's normal year runs from 9°F January nights to 82°F July afternoons, with 33.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.4°C, January lows of −13°C, July highs of 28°C, 857 mm of precipitation a year.
- NOAA stationStorm Lake
- Station IDUSC00137979
- Location42.65°N 95.19°W
- Elevation1,442 ft (440 m)
- Population11,627
On October 23, the normal high in Storm Lake is 57°F and the normal low 37°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Storm Lake.
- Jan 26° 9°
- Feb 30° 13°
- Mar 43° 25°
- Apr 58° 37°
- May 69° 49°
- Jun 79° 60°
- Jul 82° 64°
- Aug 80° 61°
- Sep 74° 53°
- Oct 61° 40°
- Nov 44° 27°
- Dec 31° 15°
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 Storm Lake each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 9°F. The most precipitation falls in June (5.33 in), the least in January (0.77 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 26°F | 9°F | 17.3°F | 0.77 | – | <1 | 31 | 9 h 20 min |
| February | 30°F | 13°F | 21.7°F | 1.01 | – | <1 | 27 | 10 h 30 min |
| March | 43°F | 25°F | 34.2°F | 1.74 | – | <1 | 24 | 11 h 50 min |
| April | 58°F | 37°F | 47.5°F | 3.53 | – | <1 | 10 | 13 h 20 min |
| May | 69°F | 49°F | 59.3°F | 4.87 | – | 1 | 1 | 14 h 40 min |
| June | 79°F | 60°F | 69.7°F | 5.33 | – | 2 | <1 | 15 h 20 min |
| July | 82°F | 64°F | 73.0°F | 3.83 | – | 4 | <1 | 15 h |
| August | 80°F | 61°F | 70.6°F | 4.43 | – | 2 | <1 | 14 h |
| September | 74°F | 53°F | 63.3°F | 2.96 | – | 1 | <1 | 12 h 30 min |
| October | 61°F | 40°F | 50.1°F | 2.42 | – | <1 | 8 | 11 h 10 min |
| November | 44°F | 27°F | 35.5°F | 1.75 | – | <1 | 22 | 9 h 50 min |
| December | 31°F | 15°F | 23.2°F | 1.11 | – | <1 | 30 | 9 h |
| Year (annual) | 57°F | 38°F | 47.1°F | 33.75 | – | 10 | 151 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −3°C | −13°C | −8.2°C | 20 mm |
| February | −1°C | −10°C | −5.7°C | 26 mm |
| March | 6°C | −4°C | 1.2°C | 44 mm |
| April | 15°C | 3°C | 8.6°C | 90 mm |
| May | 21°C | 10°C | 15.2°C | 124 mm |
| June | 26°C | 16°C | 20.9°C | 135 mm |
| July | 28°C | 18°C | 22.8°C | 97 mm |
| August | 27°C | 16°C | 21.4°C | 113 mm |
| September | 23°C | 11°C | 17.4°C | 75 mm |
| October | 16°C | 4°C | 10.1°C | 61 mm |
| November | 7°C | −3°C | 1.9°C | 44 mm |
| December | 0°C | −9°C | −4.9°C | 28 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Sioux Rapids (18 miles away), gets 35 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137979; 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 Storm Lake?
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 USC00137979.
When is the last frost in Storm Lake?
In Storm Lake, the last spring frost (32°F) comes after April 25 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 13 in half of years and before October 1 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 251 year in 10 after May 7; 9 in 10 after April 11
- First autumn frost, half of years before
- October 131 year in 10 before October 1; 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 15 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Storm Lake in zone 5a in ZIP code 50588, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Storm Lake's NOAA station is in zone 5b: the coldest night of a typical year reaches −15°F (16 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 USC00137979; 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 Storm Lake?
In a normal year in Storm Lake, 10 days a year reach 90°F and 151 nights fall to 32°F or colder.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 151a normal year
- Days that stay below freezing
- 64high of 32°F or less
The highest temperature in this station's record (since 1893) is 109°F, on July 4, 1936; the lowest is −34°F, on February 3, 1905.
The wettest calendar year on that record is 1951, with 45.94 in; the snowiest season is 1982–83, with 73.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00137979; records: ACIS (NOAA Regional Climate Centers), station USC00137979. Records use complete months only; a month missing more than three days is left out.
How sunny is Storm Lake?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Storm Lake, 4.1 kWh per square metre a day. July is the sunniest month (84%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.0 |
| February | 77% | 3.1 |
| March | 70% | 3.9 |
| April | 70% | 4.9 |
| May | 71% | 5.7 |
| June | 77% | 6.4 |
| July | 84% | 6.6 |
| August | 81% | 5.6 |
| September | 79% | 4.5 |
| October | 74% | 3.1 |
| November | 73% | 2.2 |
| December | 70% | 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 Storm Lake need?
A normal year in Storm Lake brings 7,230 heating degree days, 35% more than the median U.S. place (5,373), and 754 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 2,908 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,479 | 0 |
| February | 1,211 | 0 |
| March | 954 | 1 |
| April | 530 | 5 |
| May | 225 | 47 |
| June | 30 | 171 |
| July | 6 | 254 |
| August | 15 | 190 |
| September | 129 | 79 |
| October | 470 | 8 |
| November | 887 | 0 |
| December | 1,296 | 0 |
| Year (annual) | 7,230 | 754 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137979. 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 Storm Lake been warmer than normal lately?
2025 averaged 48.9°F, 1.8°F above the 1991-2020 normal of 47.1°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 49.3°F | +2.2°F | 29.95 |
| 2022 | 46.4°F | −0.8°F | 21.13 |
| 2023 | 48.9°F | +1.8°F | 32.89 |
| 2024 | 50.5°F | +3.4°F | 32.71 |
| 2025 | 48.9°F | +1.8°F | 34.12 |
Over 91 complete years from 1890 to 2025, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00137979; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Storm Lake's climate compare?
Storm Lake is warmer than 49 of the other 131 places with their own NOAA record in Iowa, and wetter than 29. Across the 7,247 U.S. stations with normals, its annual mean of 47.1°F is warmer than 28%.
In the Köppen classification computed from these normals, Storm Lake 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 Storm Lake share this climate record?
5 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.
- Alta, IA2,039 people · 6 mi W
- Newell, IA850 people · 10 mi E
- Schaller, IA702 people · 12 mi SW
- Lakeside, IA695 people · 2 mi S
- Truesdale, IA64 people · 6 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 Storm Lake's climate
What is the coldest month in Storm Lake?
January, with a normal high of 26°F and a normal low of 9°F. The warmest is July (82°F by day, 64°F at night).
Does it snow in Storm Lake?
Yes. NOAA publishes no 1991-2020 snowfall normal for Storm Lake's NOAA station; the nearest record that keeps one, Sioux Rapids (18 miles away), records 35 inches of snow in a normal year.
What is the rainiest month in Storm Lake?
June, with 5.33 in of precipitation in a normal year; the driest is January with 0.77 in.
What plant hardiness zone is Storm Lake in?
The USDA's 2023 map puts Storm Lake in zone 5a in ZIP code 50588, the nearest ZIP area. By the same method at Storm Lake's NOAA station, the coldest night of a typical year reaches −15°F (16 years, 1991-2020): zone 5b.
How late can frost come in Storm Lake?
In half of years the last 32°F night comes after April 25; in one year in ten it comes after May 7. Waiting until May 7 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 Rapids, IA18 miles from this station, 46.4°F a year
- Cherokee, IA19 miles from this station, 46.7°F a year
- Sac City, IA19 miles from this station, 46.6°F a year
- Holstein, IA21 miles from this station, 46.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made