Atlantic, Iowa climate: Normal weather by month, frost dates and records
Atlantic's normal year runs from 10°F January nights to 86°F July afternoons, with 37.1 inches of precipitation and 27 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.6°C, January lows of −12°C, July highs of 30°C, 943 mm of precipitation a year.
- NOAA stationAtlantic (1 mi NE)
- Station IDUSC00130364
- Location41.42°N 95.00°W
- Elevation1,152 ft (351 m)
- From the center2 miles
- Population6,717
On October 22, the normal high in Atlantic is 62°F and the normal low 36°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Atlantic.
- Jan 31° 10°
- Feb 36° 14°
- Mar 50° 25°
- Apr 63° 36°
- May 73° 49°
- Jun 83° 60°
- Jul 86° 64°
- Aug 84° 61°
- Sep 78° 51°
- Oct 65° 38°
- Nov 49° 25°
- Dec 36° 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 Atlantic each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 10°F. The most precipitation falls in June (5.74 in), the least in January (0.86 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 10°F | 20.6°F | 0.86 | 5.1 | 6 | <1 | 30 | 9 h 30 min |
| February | 36°F | 14°F | 24.9°F | 1.14 | 7.9 | 7 | <1 | 26 | 10 h 40 min |
| March | 50°F | 25°F | 37.4°F | 1.89 | 3.4 | 8 | <1 | 23 | 11 h 50 min |
| April | 63°F | 36°F | 49.3°F | 3.81 | 0.5 | 12 | <1 | 10 | 13 h 20 min |
| May | 73°F | 49°F | 61.2°F | 5.43 | 0.0 | 14 | 1 | 1 | 14 h 30 min |
| June | 83°F | 60°F | 71.3°F | 5.74 | 0.0 | 12 | 5 | <1 | 15 h 10 min |
| July | 86°F | 64°F | 74.8°F | 4.40 | 0.0 | 10 | 9 | <1 | 14 h 50 min |
| August | 84°F | 61°F | 72.5°F | 4.44 | 0.0 | 9 | 6 | <1 | 13 h 50 min |
| September | 78°F | 51°F | 64.5°F | 3.35 | 0.0 | 9 | 3 | 1 | 12 h 30 min |
| October | 65°F | 38°F | 51.5°F | 2.93 | 0.7 | 9 | <1 | 9 | 11 h 10 min |
| November | 49°F | 25°F | 37.3°F | 1.65 | 2.0 | 6 | <1 | 22 | 9 h 50 min |
| December | 36°F | 15°F | 25.8°F | 1.50 | 7.7 | 7 | <1 | 29 | 9 h 10 min |
| Year (annual) | 61°F | 37°F | 49.3°F | 37.14 | 27.3 | 107 | 22 | 152 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −12°C | −6.3°C | 22 mm | 13 cm |
| February | 2°C | −10°C | −3.9°C | 29 mm | 20 cm |
| March | 10°C | −4°C | 3.0°C | 48 mm | 9 cm |
| April | 17°C | 2°C | 9.6°C | 97 mm | 1 cm |
| May | 23°C | 10°C | 16.2°C | 138 mm | 0 cm |
| June | 28°C | 15°C | 21.8°C | 146 mm | 0 cm |
| July | 30°C | 18°C | 23.8°C | 112 mm | 0 cm |
| August | 29°C | 16°C | 22.5°C | 113 mm | 0 cm |
| September | 26°C | 10°C | 18.1°C | 85 mm | 0 cm |
| October | 18°C | 3°C | 10.8°C | 74 mm | 2 cm |
| November | 10°C | −4°C | 2.9°C | 42 mm | 5 cm |
| December | 2°C | −9°C | −3.4°C | 38 mm | 20 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00130364; 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 Atlantic?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. 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 USC00130364.
When is the last frost in Atlantic?
In Atlantic, the last spring frost (32°F) comes after April 30 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 2 in half of years and before September 17 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 15; 9 in 10 after April 17
- First autumn frost, half of years before
- October 21 year in 10 before September 17; 9 in 10 before October 16
NOAA puts the median frost-free season at 153 days, and the season without a hard freeze (28°F) at 171 days.
A hard freeze (28°F) comes after April 22 in half of springs and before October 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Atlantic in zone 5a in ZIP code 50022, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Atlantic's NOAA station is in zone 5a: the coldest night of a typical year reaches −19°F (30 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 USC00130364; 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 Atlantic?
In a normal year in Atlantic, 22 days a year reach 90°F (1 of them 100°F or more), 152 nights fall to 32°F or colder and 107 days bring measurable precipitation.
- Days at 90°F or more
- 22a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 152a normal year
- Days that stay below freezing
- 47high of 32°F or less
- Days with 0.01 inch of precipitation
- 107a normal year
- Days with 1 inch of snow or more
- 9a normal year
The highest temperature in this station's record (since 1893) is 117°F, on July 25, 1936; the lowest is −37°F, on January 12, 1974.
The wettest calendar year on that record is 1993, with 52.24 in; the snowiest season is 1911–12, with 69.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00130364; records: ACIS (NOAA Regional Climate Centers), station USC00130364. Records use complete months only; a month missing more than three days is left out.
How sunny is Atlantic?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Atlantic, 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 Atlantic need?
A normal year in Atlantic brings 6,638 heating degree days, 24% more than the median U.S. place (5,373), and 940 cooling degree days, 4% 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 3,215 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,378 | 0 |
| February | 1,123 | 0 |
| March | 857 | 1 |
| April | 478 | 7 |
| May | 180 | 62 |
| June | 19 | 208 |
| July | 3 | 307 |
| August | 11 | 243 |
| September | 114 | 99 |
| October | 430 | 13 |
| November | 831 | 0 |
| December | 1,215 | 0 |
| Year (annual) | 6,638 | 940 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00130364. 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 Atlantic been warmer than normal lately?
2024 averaged 51.7°F, 2.4°F above the 1991-2020 normal of 49.3°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 50.4°F | +1.1°F | 28.72 | 32.0 |
| 2022 | 48.3°F | −1.0°F | 23.43 | 17.7 |
| 2023 | 51.1°F | +1.9°F | 27.91 | – |
| 2024 | 51.7°F | +2.4°F | 32.25 | 19.3 |
Over 105 complete years from 1897 to 2024, the station's annual mean temperature rose at a fitted 2.0°F per century (+0.11°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00130364; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Atlantic's climate compare?
Atlantic is warmer than 92 of the other 131 places with their own NOAA record in Iowa, and wetter than 73. Across the 7,247 U.S. stations with normals, its annual mean of 49.3°F is warmer than 37%.
In the Köppen classification computed from these normals, Atlantic 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 Atlantic 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.
- Anita, IA953 people · 12 mi E
- Walnut, IA728 people · 12 mi NW
- Lewis, IA358 people · 9 mi SW
- Massena, IA352 people · 17 mi SE
- Cumberland, IA248 people · 12 mi SE
- Brayton, IA138 people · 10 mi NE
- Marne, IA109 people · 6 mi W
- Wiota, IA91 people · 6 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 Atlantic's climate
What is the coldest month in Atlantic?
January, with a normal high of 31°F and a normal low of 10°F. The warmest is July (86°F by day, 64°F at night).
Does it snow in Atlantic?
Yes: 27 inches in a normal year, falling on 19 days with 0.1 inch or more, the most in February (7.9 inches).
What is the rainiest month in Atlantic?
June, with 5.74 in of precipitation in a normal year; the driest is January with 0.86 in.
What plant hardiness zone is Atlantic in?
The USDA's 2023 map puts Atlantic in zone 5a in ZIP code 50022, the nearest ZIP area. By the same method at Atlantic's NOAA station, the coldest night of a typical year reaches −19°F (30 years, 1991-2020): zone 5a.
How late can frost come in Atlantic?
In half of years the last 32°F night comes after April 30; 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
- Audubon, IA21 miles from this station, 47.0°F a year
- Oakland, IA21 miles from this station, 49.4°F a year
- Harlan, IA23 miles from this station, 49.5°F a year
- Greenfield, IA30 miles from this station, 49.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made